Background The environmental impact of feedlot operations is a growing concern,as cattle excrete a significant portion of feed nutrients as waste.Exogenous feed enzymes(EFE)have gained interest for their potential to ...Background The environmental impact of feedlot operations is a growing concern,as cattle excrete a significant portion of feed nutrients as waste.Exogenous feed enzymes(EFE)have gained interest for their potential to enhance feed efficiency in ruminants by improving nutrient digestion.However,EFE effects on ruminal parameters have shown inconsistencies,with limited research on nitrogen metabolism and rumen microbiome impacts.Moreover,the synergistic effects of combining different EFEs remain unclear.This study aimed to evaluate the effects of individual and combined EFE products in feedlot diets on ruminal fermentation parameters,nitrogen metabolism,and ruminal microbial communities.Ten rumen-cannulated Nellore steers[543±28.6 kg of body weight(BW)]were distributed in a replicated Latin-square design(5×5)in individual pens.Treatments included:control(CON,no EFE supplementation),amylase[AML,0.5 g/kg of diet dry matter(DM)],xylanase(FBL,0.9 g/kg DM),half dose combination(HD,0.25 g of AML+0.45 g of FBL/kg of DM),and full dose combination(FD,0.5 g of AML+0.90 g of FBL/kg of DM).The experimental period lasted 19 d and included total urine and feces collection(d 15 to 18)and rumen fluid sampling(d 19)at 0,4,8,12,and 16 h post-feeding for ammonia,volatile fatty acids(VFA),pH and microbiome analysis.Results EFE supplemented animals exhibited lower ruminal ammonia concentrations(P=0.040),and higher acetate proportions(P<0.001)compared to the control group.EFE supplementation resulted in reduced nitrogen(N)excretion in feces(P=0.049)and urine(P=0.036),contributing to improved N retention and efficiency(P=0.045).Additionally,EFE products induced shifts in various microbial taxa at family and genera levels(P≤0.10),which may be associated with the changes observed in ruminal fermentation.Conclusions Our findings demonstrate that EFE supplementation enhances nitrogen retention,reduces ruminal ammonia,and alters ruminal fermentation profiles and microbial populations in feedlot cattle.While the expected synergism between amylase and xylanase did not significantly impact rumen fermentation parameters,it did induce shifts in the rumen microbiome.These results suggest that EFE supplementation may be a promising strategy for improving nutrient utilization and potentially reducing the environmental impact of feedlot operations.展开更多
Natural enzymes are able to precisely bind substrates and catalyze activities because of their distinct framework structures.To mimic this ability,chemists are designing framework structures that resemble real enzymes...Natural enzymes are able to precisely bind substrates and catalyze activities because of their distinct framework structures.To mimic this ability,chemists are designing framework structures that resemble real enzymes.The use of metal-organic frameworks(MOFs)to mimic natural enzymes has advanced recently;this paper reviews these developments.This research specifically focuses on how the catalytically active center of natural enzymes can be exactly replicated by carefully controlling the composition and structure of MOFs.By identifying and attaching to substrates,MOFs can accelerate changes in a manner akin to that of real enzymes.The role of MOFs in simulating catalytic processes,enzyme activity,and potential uses in brain chemistry are also investigated in this work.It also discusses the most recent MOF applications in detecting and treating chemical abnormalities of the brain.The report finishes with a discussion of future research areas and potential applications,providing useful insights for researchers in the subject.展开更多
[Objectives]To prepare four kinds of fruit enzymes from pitaya(dragon fruit),papaya,orange and pineapple,and to detect their physicochemical properties and antioxidant activities.[Methods]Using pitaya,papaya,orange an...[Objectives]To prepare four kinds of fruit enzymes from pitaya(dragon fruit),papaya,orange and pineapple,and to detect their physicochemical properties and antioxidant activities.[Methods]Using pitaya,papaya,orange and pineapple as raw materials,pitaya enzyme,papaya enzyme,orange enzyme and pineapple enzyme were obtained by natural fermentation.The physical and chemical properties and antioxidant activity of the four fruit enzymes were analyzed,and the dominant strains in papaya ferment were identified.[Results]The pH of the four fruit enzymes ranged from 3.32 to 3.59.The sensory evaluation of orange and papaya enzymes was relatively superior;among them,the orange enzyme exhibited the highest hydroxyl radical scavenging rate(95.76%),while the pineapple enzyme had the highest total phenol content(27.21μg/mL).The papaya enzyme showed the highest values for DPPH,reducing power,and flavonoids,at 70.55,1.699,and 0.1216 mg/mL,respectively.Through the comprehensive comparing,the physicochemical properties and antioxidant activity of the papaya enzyme were relatively superior,with its dominant microbial species being Lactobacillus and Saccharomyces cerevisiae.[Conclusions]Papaya enzyme is a kind of functional food with great development potential,and this study can provide reference for the development of fruit enzyme with high added value.展开更多
DNA repair enzymes are important in the repair of DNA lesions for maintaining the genome stability,and their abnormal expression induced various human cancers.Simultaneous detection of these DNA enzymes could provide ...DNA repair enzymes are important in the repair of DNA lesions for maintaining the genome stability,and their abnormal expression induced various human cancers.Simultaneous detection of these DNA enzymes could provide convincing evidence based on the comparison of the activity of multiple enzymes than on that of single enzyme.Although fluorescence approach has been applied for the simultaneous detection both of DNA repair enzymes,the spectral overlap and multiwavelength excitation severely restrict the number of available fluorophores.Thus,it is difficult to simultaneously detect three enzymes in a single analysis by fluorescence detection.Herein,we developed a method for the simultaneous determination of three DNA repair enzymes including human flap DNA endonuclease 1(FEN1),human alkyladenine DNA glycosylase(hAAG)and uracil DNA glycosylase(UDG)based on the combination of template-free amplification system with capillary electrophoresis-laser induced fluorescence(CE-LIF)detection.The amplification system was adopted to transfer and amplify the enzymatic products into different length DNA fragments which could be separated effectively by CE-LIF without the complicated modification of the capillary inner wall or labeling different tails on signal probes for separation.The method demonstrated a detection limit of 0.07 U/mL(0.08-160 U/mL)for FEN1,2.40 U/mL(2.5-250U/mL)for hAAG and 2.1×10^(-4)U/mL(0.0004-2.5 U/mL)for UDG,the relative standard deviations(RSDs)of peak time and peak area for different analytes were as follows:2.50%-4,37%and 3.24%-7.18%(inter-day);1.37%-2.71%and 1.43%-3.02%(intra-day),4.28%-6.08%and 4.16%-7.57%(column to column),respectively.And it can identify the inhibitor-like drugs,evaluate enzymatic kinetics and achieve the detection of three enzymes in cell extracts,providing a simple and powerful platform for simultaneous detection of more DNA repair enzymes.展开更多
The acetylpolyamine oxidase(APAO),spermine oxidase(SMO),and spermidine/spermine N1-acetyltransferase(SSAT)are pivotal enzymes in polyamine metabolism,exerting direct influence on polyamine homeostasis regulation.Dysfu...The acetylpolyamine oxidase(APAO),spermine oxidase(SMO),and spermidine/spermine N1-acetyltransferase(SSAT)are pivotal enzymes in polyamine metabolism,exerting direct influence on polyamine homeostasis regulation.Dysfunctions in these enzymes are intricately linked to inflammatory diseases and cancers.Establishing their three-dimensional structures is essential for exploring enzymatic catalytic mechanisms and designing inhibitors at the atomic level.This article primarily assesses the precision of AlphaFold2 and molecular dynamics simulations in determining the three-dimensional structures of these enzymes,utilizing protein conformation rationality assessment,residue correlation matrix,and other techniques.This provides robust models for subsequent polyamine catabolic metabolism calculations and offers valuable insights for modeling proteins that have yet to acquire crystal structures.展开更多
BACKGROUND Elevated liver enzymes in rheumatoid arthritis(RA)are often attributed to multiple factors including disease activity and treatment-related adverse effects.Tumor necrosis factor inhibitors(TNFi)have shown m...BACKGROUND Elevated liver enzymes in rheumatoid arthritis(RA)are often attributed to multiple factors including disease activity and treatment-related adverse effects.Tumor necrosis factor inhibitors(TNFi)have shown mixed effects on liver function,with varying safety profiles among agents.AIM To evaluate the hepatic safety of TNFi therapy—etanercept and adalimumab—in RA patients with elevated liver enzymes.METHODS A retrospective chart review was conducted for RA patients with elevated liver enzymes receiving TNFi at a single center between January 1,2019,and September 30,2024.Out of the patients screened,9 met the inclusion criteria.Trends in liver enzymes,fibrosis-4(FIB-4)score,and changes in the Child-Pugh class were analyzed at 1-year and 3-year follow-up periods.RESULTS Among 9 patients(4 on adalimumab,5 on etanercept),the median age was 56 years[interquartile range(IQR):49.5–64.5 years],77.8%were female,and the median body mass index was 36.99 kg/m²(IQR:30.95–43.43 kg/m²).Median baseline FIB-4 was 1.25(IQR:1.02–1.65),with no cirrhosis observed at baseline.Aspartate aminotransferase,alanine aminotransferase,and alkaline phosphatase levels declined consistently,with significant reductions from baseline to 3 years(P=0.003).FIB-4 scores also significantly decreased(P=0.003),while albumin,bilirubin,and Child-Pugh class remained stable at the 3-year follow-up.At 3 years,66.7%achieved RA remission(P=0.03).CONCLUSION TNFi therapy(adalimumab or etanercept)was associated with significant improvement in liver enzymes and FIB-4 without hepatic decompensation,supporting its safety in our cohort of RA patients with liver involvement.Larger prospective studies are warranted to further validate these findings.展开更多
Hydrogen-bonded framework(HOF) offers an attractive platform to encapsulate enzymes and stabilize their conformation,due to the advantages of mild synthesis conditions,tailorable pore structure,and backbone biocompati...Hydrogen-bonded framework(HOF) offers an attractive platform to encapsulate enzymes and stabilize their conformation,due to the advantages of mild synthesis conditions,tailorable pore structure,and backbone biocompatibility.However,the efficiency of this HOF approach relies on the interfacial interactions between enzyme vip and the ligand precursors,limiting its adaptability to enzymes with varying surface chemistry property.In this study,we report a site-specific surface modification strategy to positively tailor the enzyme surface charge,facilitating the biomimetic encapsulation of enzymes within HOF in situ.Both experimental results and computational simulation reveal that site-specific amination of enzyme surface's acidic residues contributes to the interfacial accumulation of carboxylic ligand precursors in aqueous solutions via synergistic electrostatic and hydrogen bonding interactions.This substantially facilitates the in situ growth of porous HOF surrounding the aminated enzyme biotemplates,with up to 100% enzyme loading efficiency.The resultant hydrogen-bonded biohybrid framework(HBF) retains high biocatalytic functions while exhibiting exceptional stability under harsh conditions.By leveraging the marked catalytic activity of GOx-NH_(2)@HBF-1 and a H_(2)O_(2)-sensitive QD,a highly sensitive glucose fluorescence sensor is fabricated with a wide linear range(5-2000 μmol/L) and a low quantification limit of 5 μmol/L.This work presents a simple yet effective enzyme surface engineering approach for integrating enzyme into HOF,opening new avenues for the construction of multifunctional HOF biocomposites.展开更多
Cytochrome P450 enzymes(P450s or CYPs)are the primary metabolic contributors to the absorption,distribution,metabolism,and excretion(ADME)properties of small-molecule drugs.These enzymes can catalyze various types of ...Cytochrome P450 enzymes(P450s or CYPs)are the primary metabolic contributors to the absorption,distribution,metabolism,and excretion(ADME)properties of small-molecule drugs.These enzymes can catalyze various types of reactions,including metabolic reactions that occur at nitrogen(N)and sulfur(S)sites of small molecules.In this review,we conducted a comprehensive statistical analysis of 294 P450s-mediated small-molecule substrates,among which more than 47%substrates contained N and S.The purpose of the analysis is to elucidate the broad-spectrum cross-reactivity and specificity between these substrates and various CYP isoforms across five reaction types.Our findings reveal that substrates with molecular weights greater than 500 Da or less than 200 Da are predominantly governed by the dominant effect of the CYP isoform’s active sites.In contrast,small-to medium-sized molecules with molecular weights ranging from 200 to 400 Da exhibit a stronger dependence on the types of heteroatoms they contain,with the size of the enzyme’s catalytic site(cavity)playing a negligible role in determining substrate specificity.This review starts from the metabolic mechanisms of P450s-mediated N-and S-containing compounds,and systematically analyzes the structural characteristics of substrates involved in N-dealkylation,N-oxidation,and S-oxidation,as well as their metabolic interactions with P450s.These analyses provide a new perspective for improving the existing understanding of the relationship between the P450s substrate specificity and substrate structural characteristics,and offer a valuable perspective for enhancing drug design and predicting metabolic stability based on the P450s-catalyzed reaction framework.展开更多
BACKGROUND Chronic nonhealing wounds,such as diabetic foot ulcer(DFU),suffer from delayed healing.Identifying effective biomarkers or targets is crucial for managing these refractory wounds.While N7-methylguanosine(m7...BACKGROUND Chronic nonhealing wounds,such as diabetic foot ulcer(DFU),suffer from delayed healing.Identifying effective biomarkers or targets is crucial for managing these refractory wounds.While N7-methylguanosine(m7G)methylation is important in RNA modification,its connection to chronic nonhealing wounds is poorly understood.AIM To assess the potential m7G biomarkers in DFU and their underlying molecular mechanisms.METHODS Differential expression analysis and weighted gene coexpression network analysis identified key genes in DFU.Hub genes were determined through m7G-DFU intersection,and gene set enrichment analysis was conducted.Diagnostic potential of hub genes was assessed using receiver operating characteristic curves.The hub gene’s expression(decapping scavenger enzyme,DCPS)was confirmed using quantitative reverse transcription polymerase chain reaction and immunofluorescence.In vitro,normal human epidermal keratinocyte models were knocked down for DCPS,and the function was assessed through flow cytometry,western blotting,immunofluorescence,Transwell assays,and scratch assays.RESULTS Weighted gene coexpression network analysis and differential expression analysis revealed links between DFU datasets and methylation processes,identifying hub gene DCPS as a candidate biomarker.Notably,its diagnostic value was confirmed with a test set and receiver operating characteristic curve,achieving an area under the curve of 0.98 and 0.99.Quantitative reverse transcription polymerase chain reaction and immunofluorescence analyses showed significantly reduced expression of DCPS in the wound skin of DFU patients and streptozotocin-induced diabetic mice,indicating its role as a regulatory factor of m7G in diabetic wounds.Mechanistically,in vitro studies showed that DCPS knockdown significantly reduced cyclin-dependent kinase 6 and cyclin D1 expression,disrupted the epithelial cell cycle,inhibited cell proliferation and migration,and increased apoptosis rates.CONCLUSION DCPS was identified as a promising DFU biomarker and therapeutic target,regulating m7G to affect cell cycle,proliferation,and epithelial cell migration during DFU wound healing.展开更多
Background:Corchorus olitorius L.(Malvaceae)is a green leafy vegetable widely consumed in the Middle East and valued for its rich nutritional content.Its essential oils,an important class of secondary metabolites,are ...Background:Corchorus olitorius L.(Malvaceae)is a green leafy vegetable widely consumed in the Middle East and valued for its rich nutritional content.Its essential oils,an important class of secondary metabolites,are of growing interest for potential use in cosmetics and fragrance industries due to their bioactive properties.Methods:Leaves of C.olitorius cultivated in Egypt were extracted using microwave-assisted hydrodistillation(MAHD)and conventional hydrodistillation(HD).The oils were analyzed by gas chromatography-mass spectrometry(GC-MS)to characterize their chemical profiles.In vitro assays were conducted to evaluate their anti-elastase and anti-collagenase activities,and in silico studies were performed to predict the pharmacokinetic and pharmacodynamic properties of major constituents.Results:GC-MS analysis showed that aldehydes,alkanes,fatty alcohols,fatty acids,and their derivatives were the predominant compound classes in both oils.Notably,oxygenated diterpenes(11.22%)were present exclusively in the MAHD oil,while triterpenoids(16.37%)were found only in the HD oil.The MAHD oil demonstrated stronger In vitro anti-elastase(IC_(50)=42.5μg/mL)and anti-collagenase(IC_(50)=131.5μg/mL)activities compared to the HD oil(IC_(50)=66.7 and 206.8μg/mL,respectively),reflecting an approximate 36.3%improvement in elastase inhibition and 36.4%improvement in collagenase inhibition.In silico docking indicated that the triterpenoidβ-amyrin acetate showed the highest predicted binding affinity for porcine pancreatic elastase(PDB ID:6QEO,ΔG=−8.1 kcal/mol)and collagenase(PDB ID:456C,ΔG=−9.1 kcal/mol)among the major compounds analyzed.Conclusion:These findings demonstrate that MAHD is a greener and more efficient extraction method,yielding oil with enhanced enzyme inhibitory activity compared to conventional HD.The promising anti-elastase and anti-collagenase properties suggest that C.olitorius MAHD oil could serve as a potential candidate for anti-aging cosmetic formulations,following further validation.展开更多
Recent progress in nanotechnology has provided high-performance nanomaterials for enzyme immobilization.Nanobiocatalysts combining enzymes and nanocarriers are drawing increasing attention because of their high cataly...Recent progress in nanotechnology has provided high-performance nanomaterials for enzyme immobilization.Nanobiocatalysts combining enzymes and nanocarriers are drawing increasing attention because of their high catalytic performance,enhanced stabilities,improved enzyme-substrate affinities,and reusabilities.Many studies have been performed to investigate the efficient use of cellulose nanocrystals,polydopamine-based nanomaterials,and synthetic polymer nanogels for enzyme immobilization.Various nanobiocatalysts are highlighted in this review,with the emphasis on the design,preparation,properties,and potential applications of nanoscale enzyme carriers and nanobiocatalysts.展开更多
[ Objective] The aim was to study the effect of 12C6 ＋ ions beam irradiation to two varieties of sweet sorghum on seed germination and some enzymes activity in seedlings with different doses, and provided a theoretic...[ Objective] The aim was to study the effect of 12C6 ＋ ions beam irradiation to two varieties of sweet sorghum on seed germination and some enzymes activity in seedlings with different doses, and provided a theoretical foundation for sweet sorghum breeding. [ Method] After germination, the germination potential, germination fraction and enzyme activity were detected, respectively. [ Result] The results showed that with the dose increased, the germination potential of sweet sorghum increased first and then decreased, while their germination fraction presented ＂shoulder like shape＂ ; the activity of LDH, SOD, CAT and GSH-Px increased first and then decreased with doses, they presented slight differences among different enzymes. [ Conclusion] Low dose radiation could accelerate germination of sweet sorghum seeds and enzyme activity could remain at a relatively high level. Enzyme activity decreased with high doses and the growth of sweet sorghum was inhibited.展开更多
[Objective] The purpose was to study the effects of different arbuscular mycorrhizal fungi strains（AMF）on the mineral nutrition and antioxidant enzymes of Chrysanthemum morifolium.[Method] The pot experiment was con...[Objective] The purpose was to study the effects of different arbuscular mycorrhizal fungi strains（AMF）on the mineral nutrition and antioxidant enzymes of Chrysanthemum morifolium.[Method] The pot experiment was conducted in the greenhouse,C.morifolium ＇Jinba＇ was inoculated with five kinds of AMF,N,P,K,malondial dehyde（MDA）content,as well as the superoxide dismutase（SOD）,peroxidase（POD） and catalase（CAT） activity in roots,leaves and petals of C.morifolium were measured at seedling and flowering stages.[Result] The G.i,G.e and G.m treatments could promote mineral nutrient absorption,increase N,P,K content in roots,leaves and petals of C.morifolium compared with the control without inoculation.The G.d、G.e and G.m treatments could significantly reduce MDA content in roots and petals,thus alleviating membrane permeability and lipid peroxidation.The G.i treatments could also improve the SOD,POD and CAT activities of C.morifolium,thereby increasing the capability of scavenging oxygen free radicals.[Conclusion] According to the comprehensive analysis,G.i was screened out as the best strain to improve mineral nutrition and antioxidant enzyme activities of C.morifolium.展开更多
The eelgrass ( Zostera marina L.) was treated with artificial seawater (ASW) of different salinities ( 100%, 150% and 200% seawater) for 5 d. The activities of two enzymes extracted from the plant leaves were determin...The eelgrass ( Zostera marina L.) was treated with artificial seawater (ASW) of different salinities ( 100%, 150% and 200% seawater) for 5 d. The activities of two enzymes extracted from the plant leaves were determined under a salinity grade in vitro So were the photosynthesis rates of the plants from the three treatments in the media with different salinities 100%, 150%, 200%, 300% ASW) and Some physiological data. The data showed that under increased salinities (concentrated seawater), Na+, Cl-, MDA (malon dialdehyde) and glucose contents and the osmotic potentials ( absolute value) in the leaves increased with the salinity elevation in the medium (ASW), but both K+ and free amino acid (mainly proline) contents decreased. Malate dehydrogenase (MDH) from the plant leaves under a salinity grade showed its activities (A) as follows: A(100%) (ASW) > A(150%) (ASW) > A(200%) (ASW). Phosphoenolpyruvate carboxylase (PEPC) extracted from the 100% ASW- and 200% ASW-treated plants showed similar activities (both insensitive to salinities) under the salinity grade in vitro, but the activities of PEPC from plants treated with 150% ASW were dependent oil salinity. Whether the plant is stressed at 150% ASW and can stand higher salinity than seawater needs to be studied further. Meantime, die data do not agree with the opinion that the adaptation of the eelgrass to seawater salinity is partly fulfilled by its insensitiveness to salinities in Some metabolic enzymes. It can be inferred that the lack of transpiration may be an important aspect of tire plant's tolerance to seawater salinity.展开更多
The leaves of Bt (Bacillus thuringiensis) transgenic poplar (Populus nigra L.) and CpTI (Cowpea trypsin inhibitor) transgenic poplar ((P. tomentosa×P. bolleana)×P. Tomentosa) were taken to feed the 4th-5th-i...The leaves of Bt (Bacillus thuringiensis) transgenic poplar (Populus nigra L.) and CpTI (Cowpea trypsin inhibitor) transgenic poplar ((P. tomentosa×P. bolleana)×P. Tomentosa) were taken to feed the 4th-5th-instar larvae of American white moth (Hyphantria cunea (Drury)) for determination of the activities of the protective enzyme system inside larvae’s body. The physiological and biochemical effects of the transgenic poplars on the larvae were studied. The results showed that the two kinds of transgenic poplars had similar effects on the protective enzyme system in the midgut of larvae. The activities of superoxide dismutase, catalase, and peroxidase in midgut of the larvae increased gradually, reached the highest value at a certain time, and then decreased suddenly. For the larvae that were fed with the leaves of Bt transgenic poplar, the peak value of superoxide dismutase and catalase presented at the time of 24-h feeding, while the peak of peroxidase took place at the time of 12-h feeding. The activities of these protective enzymes for the larvae that were fed with leaves of CpTI transgenic poplar peaked 12 h later than that of those fed with leaves of Bt transgenic poplar. The comparison of activities of the protective enzymes was also carried out between the larvae with different levels of intoxication. It was found that the activities of protective enzyme of the seriously intoxicant larvae were higher than that of the lightly intoxicant larvae. This difference was more obvious in the group treated with CpTI transgenic poplar.展开更多
[Objective] This study aimed to determine activities of antioxidant enzymes during gland morphogenesis in cotton, thoroughly explore physiological changes of cotton and provide a scientific basis for the cultivation o...[Objective] This study aimed to determine activities of antioxidant enzymes during gland morphogenesis in cotton, thoroughly explore physiological changes of cotton and provide a scientific basis for the cultivation of excellent cotton varieties. [Method] Based on determination of gossypol contents and antioxidant enzymes ac- tivities during gland morphogenesis in three cotton varieties （Chuanmian2802, Xiang- mian18 and XianwuN5）, metabolism of gossypol and morphogenesis of gland in cot- ton were explored. [Result] After gland morphogenesis, the content of gossypol in Chuanmian2802 was gradually reduced in the early period of seed germination, which slowly increased since the 5th d after germination; however, during the seed germination period, the content of gossypol in Xiangmian18 had a slowly increasing trend and was gradually close to the content of gossypol in Chuanmian2802. The results showed that activities of SOD, POD and CAT increased in seed germination, which was contributive to remove the superoxide radicals, decrease the peroxide lev- el, reduce damages to the membrane, enhance the body＇s resistance to lipid oxida- tion and increase resistance ability to stress. [Conclusion] This study laid the scientif- ic foundation for understanding the characteristics of gland morphogenesis in cotton and cotton cultivation by using gland traits.展开更多
The distribution and ecological characters of grapefruit were analyzed mainly,and the research trends of stock and scion selection for grafting,the healing-anatomy process and enzymology were summarized systematically...The distribution and ecological characters of grapefruit were analyzed mainly,and the research trends of stock and scion selection for grafting,the healing-anatomy process and enzymology were summarized systematically.The results indicated that the range of stock and scion apolegamy decreased through the application of molecular technique.But the study on stock variety and scion selection was still in need of expanding and the key enzyme played a vital role in the healing of the stock and scion,which provided a chance for the regulation and control of healing force by hormones and also provided a theoretical basis for the regulation of gene.展开更多
[Objective] The aim was to understand defense mechanism of pear after inoculated Botryosphaeria berengeriana f. sp. piricolan and mechanism of antioxidant enzymes of biocontrol bacteria. [Method] Pears were treated by...[Objective] The aim was to understand defense mechanism of pear after inoculated Botryosphaeria berengeriana f. sp. piricolan and mechanism of antioxidant enzymes of biocontrol bacteria. [Method] Pears were treated by Botryosphaeria berengeriana f. sp. piricolan and bio control bacteria, and the change of antioxidant enzymes were determined. [Result] The biocontrol bacteria had little effect on MDA;the content of MDA treated by B. berengeriana reached high peak in 48 h, was 10.22nmol/g which was 1.86 times of CK; the content of MDA treated by B. berengeriana and biocontrol bacteria reached high peak in 24 h, was 8.92 nmol/g which was1.62 times of CK. The content of SOD treated by biocontrol bacteria reached high peak in 48 h, was 126.69 U/[g（FW）·min] which was 1.54 times of CK; the contents of SOD treated by B. berengeriana as well as B. berengeriana and biocontrol bacteria reached high peak in 24 h, were 122.10 and 135.32 U/[g（FW）·min] which were 1.48 and 1.65 times of CK respectively; the contents of POD on biocontrol bacteria treatment, B. ana treatment as well as B. berengeriana and biocontrol bacteria treatment reached high peak in 24 h, were 385.34, 342.50 and 290.00 U/[g（FW）·min] which were 1.83, 1.62 and 1.38 times of CK respectively. The contents of CAT on biocontrol bacteria treatment, B. rengeriana treatment as well as B. berengeriana and biocontrol bacteria treatment reached high peak in 6 h, were 133.33,114.17 and 113.35 U/[g（FW）·min] which were 1.33, 1.14 and 1.13 times of CK respectively. The biocontrol bacteria had little difference in CK; the content of PPO of B. berengeriana treatment reached high peak in 12 h, was 81.86 U/[g（FW）·min]which was 1.76 times of CK; B. berengeriana and biocontrol bacteria treatment reached high peak in 24 h, was 70.00 U/[g（FW）·min] which was 1.50 times of CK.[Conclusion] B. berengeriana and biocontrol bacteria had more effect on MDA; both B. berengeriana and biocontrol bacteria could increase the excitation of SOD enzyme activity; both B. berengeriana and biocontrol bacteria could increase the excitation of POD enzyme activity; both B. berengeriana and biocontrol bacteria could increase the excitation of CAT enzyme activity; using biocontrol bacteria alone had not obvious effect on PPO, B. berengeriana could increase the excitation of PPO enzyme activity.展开更多
The 3＇-OH, 4＇-OH and 2＂-OH of kanamycin A were modified in search of new aminoglycosides to overcome resistant enzymes, ANTs and APHs. The key intermediate was a dibenzylidene-protected derivative of kanamycin A. T...The 3＇-OH, 4＇-OH and 2＂-OH of kanamycin A were modified in search of new aminoglycosides to overcome resistant enzymes, ANTs and APHs. The key intermediate was a dibenzylidene-protected derivative of kanamycin A. The aimed sites were masked by benzyl, methyl and allyl groups. Multi-step reactions gave the desired aminoglycoside derivatives but showed less antibiotic activity than kanamycin A.展开更多
[Objective] This study aimed to explore the effects of spores and crude toxins of Helminthosporium gramineum Rabenh f. sp. echinochloae（HGE） on the ac- tivity of defensive enzymes of barnyardgrass [Echinochloa crus-...[Objective] This study aimed to explore the effects of spores and crude toxins of Helminthosporium gramineum Rabenh f. sp. echinochloae（HGE） on the ac- tivity of defensive enzymes of barnyardgrass [Echinochloa crus-galli （L.） Beauv.]. [Method] The effects of spores and crude toxins of HGE, as well as the mixture of spores and crude toxins on the activity of defensive enzymes in barnyardgrass were determined under laboratory conditions. [Result] Spores and crude toxins of HGE had varying degrees of effects on PAL and POD activity, and no obvious effect on SOD activity in barnyardgrass. In addition, spores and toxins had some similar im- pacts on the defensive enzymes in barnyardgrass. [Conclusion] Since toxins have similar effects on the hosts as spores of fungal pathogen do, they can be a substi- tute for the fungal pathogen in studying the partial pathogenic mechanism of this pathogen due to its complexity in pathogenic process.展开更多
基金supported by the Fundacao de Amparo a Pesquisa do Estado de Sao Paulo(FAPESP,Sao Paulo,SP,BRAZIL)for the scholarship of the first authors(2019/24820-3 and 2022/00989-1)and the PDIP grant(2017/50339-5).
文摘Background The environmental impact of feedlot operations is a growing concern,as cattle excrete a significant portion of feed nutrients as waste.Exogenous feed enzymes(EFE)have gained interest for their potential to enhance feed efficiency in ruminants by improving nutrient digestion.However,EFE effects on ruminal parameters have shown inconsistencies,with limited research on nitrogen metabolism and rumen microbiome impacts.Moreover,the synergistic effects of combining different EFEs remain unclear.This study aimed to evaluate the effects of individual and combined EFE products in feedlot diets on ruminal fermentation parameters,nitrogen metabolism,and ruminal microbial communities.Ten rumen-cannulated Nellore steers[543±28.6 kg of body weight(BW)]were distributed in a replicated Latin-square design(5×5)in individual pens.Treatments included:control(CON,no EFE supplementation),amylase[AML,0.5 g/kg of diet dry matter(DM)],xylanase(FBL,0.9 g/kg DM),half dose combination(HD,0.25 g of AML+0.45 g of FBL/kg of DM),and full dose combination(FD,0.5 g of AML+0.90 g of FBL/kg of DM).The experimental period lasted 19 d and included total urine and feces collection(d 15 to 18)and rumen fluid sampling(d 19)at 0,4,8,12,and 16 h post-feeding for ammonia,volatile fatty acids(VFA),pH and microbiome analysis.Results EFE supplemented animals exhibited lower ruminal ammonia concentrations(P=0.040),and higher acetate proportions(P<0.001)compared to the control group.EFE supplementation resulted in reduced nitrogen(N)excretion in feces(P=0.049)and urine(P=0.036),contributing to improved N retention and efficiency(P=0.045).Additionally,EFE products induced shifts in various microbial taxa at family and genera levels(P≤0.10),which may be associated with the changes observed in ruminal fermentation.Conclusions Our findings demonstrate that EFE supplementation enhances nitrogen retention,reduces ruminal ammonia,and alters ruminal fermentation profiles and microbial populations in feedlot cattle.While the expected synergism between amylase and xylanase did not significantly impact rumen fermentation parameters,it did induce shifts in the rumen microbiome.These results suggest that EFE supplementation may be a promising strategy for improving nutrient utilization and potentially reducing the environmental impact of feedlot operations.
基金financially supported by the National Natural Science Foundation,China(Nos.22074095&22374103(Y.Lin))Beijing Natural Science Foundation(No.2222005(Y.Lin))。
文摘Natural enzymes are able to precisely bind substrates and catalyze activities because of their distinct framework structures.To mimic this ability,chemists are designing framework structures that resemble real enzymes.The use of metal-organic frameworks(MOFs)to mimic natural enzymes has advanced recently;this paper reviews these developments.This research specifically focuses on how the catalytically active center of natural enzymes can be exactly replicated by carefully controlling the composition and structure of MOFs.By identifying and attaching to substrates,MOFs can accelerate changes in a manner akin to that of real enzymes.The role of MOFs in simulating catalytic processes,enzyme activity,and potential uses in brain chemistry are also investigated in this work.It also discusses the most recent MOF applications in detecting and treating chemical abnormalities of the brain.The report finishes with a discussion of future research areas and potential applications,providing useful insights for researchers in the subject.
文摘[Objectives]To prepare four kinds of fruit enzymes from pitaya(dragon fruit),papaya,orange and pineapple,and to detect their physicochemical properties and antioxidant activities.[Methods]Using pitaya,papaya,orange and pineapple as raw materials,pitaya enzyme,papaya enzyme,orange enzyme and pineapple enzyme were obtained by natural fermentation.The physical and chemical properties and antioxidant activity of the four fruit enzymes were analyzed,and the dominant strains in papaya ferment were identified.[Results]The pH of the four fruit enzymes ranged from 3.32 to 3.59.The sensory evaluation of orange and papaya enzymes was relatively superior;among them,the orange enzyme exhibited the highest hydroxyl radical scavenging rate(95.76%),while the pineapple enzyme had the highest total phenol content(27.21μg/mL).The papaya enzyme showed the highest values for DPPH,reducing power,and flavonoids,at 70.55,1.699,and 0.1216 mg/mL,respectively.Through the comprehensive comparing,the physicochemical properties and antioxidant activity of the papaya enzyme were relatively superior,with its dominant microbial species being Lactobacillus and Saccharomyces cerevisiae.[Conclusions]Papaya enzyme is a kind of functional food with great development potential,and this study can provide reference for the development of fruit enzyme with high added value.
基金supported by the National Natural Science Foundation of China(Nos.21874060 and 22174058,U21A20282)the Science and Technology program of Gansu Province(No.22JR5RA476)。
文摘DNA repair enzymes are important in the repair of DNA lesions for maintaining the genome stability,and their abnormal expression induced various human cancers.Simultaneous detection of these DNA enzymes could provide convincing evidence based on the comparison of the activity of multiple enzymes than on that of single enzyme.Although fluorescence approach has been applied for the simultaneous detection both of DNA repair enzymes,the spectral overlap and multiwavelength excitation severely restrict the number of available fluorophores.Thus,it is difficult to simultaneously detect three enzymes in a single analysis by fluorescence detection.Herein,we developed a method for the simultaneous determination of three DNA repair enzymes including human flap DNA endonuclease 1(FEN1),human alkyladenine DNA glycosylase(hAAG)and uracil DNA glycosylase(UDG)based on the combination of template-free amplification system with capillary electrophoresis-laser induced fluorescence(CE-LIF)detection.The amplification system was adopted to transfer and amplify the enzymatic products into different length DNA fragments which could be separated effectively by CE-LIF without the complicated modification of the capillary inner wall or labeling different tails on signal probes for separation.The method demonstrated a detection limit of 0.07 U/mL(0.08-160 U/mL)for FEN1,2.40 U/mL(2.5-250U/mL)for hAAG and 2.1×10^(-4)U/mL(0.0004-2.5 U/mL)for UDG,the relative standard deviations(RSDs)of peak time and peak area for different analytes were as follows:2.50%-4,37%and 3.24%-7.18%(inter-day);1.37%-2.71%and 1.43%-3.02%(intra-day),4.28%-6.08%and 4.16%-7.57%(column to column),respectively.And it can identify the inhibitor-like drugs,evaluate enzymatic kinetics and achieve the detection of three enzymes in cell extracts,providing a simple and powerful platform for simultaneous detection of more DNA repair enzymes.
基金National Natural Science Foundation of China(22073023)Natural Science Foundation of Henan Province(242300421134)+1 种基金the Young Backbone Teacher in Colleges and Universities of Henan Province(2021GGJS020)Foundation of State Key Laboratory of Antiviral Drugs。
文摘The acetylpolyamine oxidase(APAO),spermine oxidase(SMO),and spermidine/spermine N1-acetyltransferase(SSAT)are pivotal enzymes in polyamine metabolism,exerting direct influence on polyamine homeostasis regulation.Dysfunctions in these enzymes are intricately linked to inflammatory diseases and cancers.Establishing their three-dimensional structures is essential for exploring enzymatic catalytic mechanisms and designing inhibitors at the atomic level.This article primarily assesses the precision of AlphaFold2 and molecular dynamics simulations in determining the three-dimensional structures of these enzymes,utilizing protein conformation rationality assessment,residue correlation matrix,and other techniques.This provides robust models for subsequent polyamine catabolic metabolism calculations and offers valuable insights for modeling proteins that have yet to acquire crystal structures.
文摘BACKGROUND Elevated liver enzymes in rheumatoid arthritis(RA)are often attributed to multiple factors including disease activity and treatment-related adverse effects.Tumor necrosis factor inhibitors(TNFi)have shown mixed effects on liver function,with varying safety profiles among agents.AIM To evaluate the hepatic safety of TNFi therapy—etanercept and adalimumab—in RA patients with elevated liver enzymes.METHODS A retrospective chart review was conducted for RA patients with elevated liver enzymes receiving TNFi at a single center between January 1,2019,and September 30,2024.Out of the patients screened,9 met the inclusion criteria.Trends in liver enzymes,fibrosis-4(FIB-4)score,and changes in the Child-Pugh class were analyzed at 1-year and 3-year follow-up periods.RESULTS Among 9 patients(4 on adalimumab,5 on etanercept),the median age was 56 years[interquartile range(IQR):49.5–64.5 years],77.8%were female,and the median body mass index was 36.99 kg/m²(IQR:30.95–43.43 kg/m²).Median baseline FIB-4 was 1.25(IQR:1.02–1.65),with no cirrhosis observed at baseline.Aspartate aminotransferase,alanine aminotransferase,and alkaline phosphatase levels declined consistently,with significant reductions from baseline to 3 years(P=0.003).FIB-4 scores also significantly decreased(P=0.003),while albumin,bilirubin,and Child-Pugh class remained stable at the 3-year follow-up.At 3 years,66.7%achieved RA remission(P=0.03).CONCLUSION TNFi therapy(adalimumab or etanercept)was associated with significant improvement in liver enzymes and FIB-4 without hepatic decompensation,supporting its safety in our cohort of RA patients with liver involvement.Larger prospective studies are warranted to further validate these findings.
基金financial support from projects of the National Natural Science Foundation of China(Nos.22104159,22174164)Guangdong Basic and Applied Basic Research Foundation(Nos.2023A1515011632,2024B1515020070)。
文摘Hydrogen-bonded framework(HOF) offers an attractive platform to encapsulate enzymes and stabilize their conformation,due to the advantages of mild synthesis conditions,tailorable pore structure,and backbone biocompatibility.However,the efficiency of this HOF approach relies on the interfacial interactions between enzyme vip and the ligand precursors,limiting its adaptability to enzymes with varying surface chemistry property.In this study,we report a site-specific surface modification strategy to positively tailor the enzyme surface charge,facilitating the biomimetic encapsulation of enzymes within HOF in situ.Both experimental results and computational simulation reveal that site-specific amination of enzyme surface's acidic residues contributes to the interfacial accumulation of carboxylic ligand precursors in aqueous solutions via synergistic electrostatic and hydrogen bonding interactions.This substantially facilitates the in situ growth of porous HOF surrounding the aminated enzyme biotemplates,with up to 100% enzyme loading efficiency.The resultant hydrogen-bonded biohybrid framework(HBF) retains high biocatalytic functions while exhibiting exceptional stability under harsh conditions.By leveraging the marked catalytic activity of GOx-NH_(2)@HBF-1 and a H_(2)O_(2)-sensitive QD,a highly sensitive glucose fluorescence sensor is fabricated with a wide linear range(5-2000 μmol/L) and a low quantification limit of 5 μmol/L.This work presents a simple yet effective enzyme surface engineering approach for integrating enzyme into HOF,opening new avenues for the construction of multifunctional HOF biocomposites.
基金support from the National Natural Science Foundation of China(8227131503).
文摘Cytochrome P450 enzymes(P450s or CYPs)are the primary metabolic contributors to the absorption,distribution,metabolism,and excretion(ADME)properties of small-molecule drugs.These enzymes can catalyze various types of reactions,including metabolic reactions that occur at nitrogen(N)and sulfur(S)sites of small molecules.In this review,we conducted a comprehensive statistical analysis of 294 P450s-mediated small-molecule substrates,among which more than 47%substrates contained N and S.The purpose of the analysis is to elucidate the broad-spectrum cross-reactivity and specificity between these substrates and various CYP isoforms across five reaction types.Our findings reveal that substrates with molecular weights greater than 500 Da or less than 200 Da are predominantly governed by the dominant effect of the CYP isoform’s active sites.In contrast,small-to medium-sized molecules with molecular weights ranging from 200 to 400 Da exhibit a stronger dependence on the types of heteroatoms they contain,with the size of the enzyme’s catalytic site(cavity)playing a negligible role in determining substrate specificity.This review starts from the metabolic mechanisms of P450s-mediated N-and S-containing compounds,and systematically analyzes the structural characteristics of substrates involved in N-dealkylation,N-oxidation,and S-oxidation,as well as their metabolic interactions with P450s.These analyses provide a new perspective for improving the existing understanding of the relationship between the P450s substrate specificity and substrate structural characteristics,and offer a valuable perspective for enhancing drug design and predicting metabolic stability based on the P450s-catalyzed reaction framework.
基金Supported by National Natural Science Foundation of China,No.82370903Noncommunicable Chronic Diseases-National Science and Technology Major Project,No.2023ZD0509400 and No.2023ZD0509402+1 种基金2023 Key Disciplines on Public Health Construction of Chongqing,the Natural Science Foundation of Chongqing Municipal Science and Technology Bureau,No.cstc2024ycjh-bgzxm0014Major Project of Science and Technology Research Program of Chongqing Education Commission of China,No.KJZD-M202400102.
文摘BACKGROUND Chronic nonhealing wounds,such as diabetic foot ulcer(DFU),suffer from delayed healing.Identifying effective biomarkers or targets is crucial for managing these refractory wounds.While N7-methylguanosine(m7G)methylation is important in RNA modification,its connection to chronic nonhealing wounds is poorly understood.AIM To assess the potential m7G biomarkers in DFU and their underlying molecular mechanisms.METHODS Differential expression analysis and weighted gene coexpression network analysis identified key genes in DFU.Hub genes were determined through m7G-DFU intersection,and gene set enrichment analysis was conducted.Diagnostic potential of hub genes was assessed using receiver operating characteristic curves.The hub gene’s expression(decapping scavenger enzyme,DCPS)was confirmed using quantitative reverse transcription polymerase chain reaction and immunofluorescence.In vitro,normal human epidermal keratinocyte models were knocked down for DCPS,and the function was assessed through flow cytometry,western blotting,immunofluorescence,Transwell assays,and scratch assays.RESULTS Weighted gene coexpression network analysis and differential expression analysis revealed links between DFU datasets and methylation processes,identifying hub gene DCPS as a candidate biomarker.Notably,its diagnostic value was confirmed with a test set and receiver operating characteristic curve,achieving an area under the curve of 0.98 and 0.99.Quantitative reverse transcription polymerase chain reaction and immunofluorescence analyses showed significantly reduced expression of DCPS in the wound skin of DFU patients and streptozotocin-induced diabetic mice,indicating its role as a regulatory factor of m7G in diabetic wounds.Mechanistically,in vitro studies showed that DCPS knockdown significantly reduced cyclin-dependent kinase 6 and cyclin D1 expression,disrupted the epithelial cell cycle,inhibited cell proliferation and migration,and increased apoptosis rates.CONCLUSION DCPS was identified as a promising DFU biomarker and therapeutic target,regulating m7G to affect cell cycle,proliferation,and epithelial cell migration during DFU wound healing.
基金Egyptian Science and Technology and Innovation Fund(STIFA)for the support of the study through grant No.46667 entitled“Sustainability of Lab Capacities of the Center of Drug Discovery Research and Development”.
文摘Background:Corchorus olitorius L.(Malvaceae)is a green leafy vegetable widely consumed in the Middle East and valued for its rich nutritional content.Its essential oils,an important class of secondary metabolites,are of growing interest for potential use in cosmetics and fragrance industries due to their bioactive properties.Methods:Leaves of C.olitorius cultivated in Egypt were extracted using microwave-assisted hydrodistillation(MAHD)and conventional hydrodistillation(HD).The oils were analyzed by gas chromatography-mass spectrometry(GC-MS)to characterize their chemical profiles.In vitro assays were conducted to evaluate their anti-elastase and anti-collagenase activities,and in silico studies were performed to predict the pharmacokinetic and pharmacodynamic properties of major constituents.Results:GC-MS analysis showed that aldehydes,alkanes,fatty alcohols,fatty acids,and their derivatives were the predominant compound classes in both oils.Notably,oxygenated diterpenes(11.22%)were present exclusively in the MAHD oil,while triterpenoids(16.37%)were found only in the HD oil.The MAHD oil demonstrated stronger In vitro anti-elastase(IC_(50)=42.5μg/mL)and anti-collagenase(IC_(50)=131.5μg/mL)activities compared to the HD oil(IC_(50)=66.7 and 206.8μg/mL,respectively),reflecting an approximate 36.3%improvement in elastase inhibition and 36.4%improvement in collagenase inhibition.In silico docking indicated that the triterpenoidβ-amyrin acetate showed the highest predicted binding affinity for porcine pancreatic elastase(PDB ID:6QEO,ΔG=−8.1 kcal/mol)and collagenase(PDB ID:456C,ΔG=−9.1 kcal/mol)among the major compounds analyzed.Conclusion:These findings demonstrate that MAHD is a greener and more efficient extraction method,yielding oil with enhanced enzyme inhibitory activity compared to conventional HD.The promising anti-elastase and anti-collagenase properties suggest that C.olitorius MAHD oil could serve as a potential candidate for anti-aging cosmetic formulations,following further validation.
基金supported by the National Natural Science Foundation of China(21336002,21222606,21376096)the Key Program of Guangdong Natural Science Foundation(S2013020013049)+2 种基金the Fundamental Research Funds for the Chinese Universities(2015PT002,2015ZP009)the Program of State Key Laboratory of Pulp and Paper Engineering(2015C04)the South China University of Technology Doctoral Student Short-Term Overseas Visiting Study Funding Project~~
文摘Recent progress in nanotechnology has provided high-performance nanomaterials for enzyme immobilization.Nanobiocatalysts combining enzymes and nanocarriers are drawing increasing attention because of their high catalytic performance,enhanced stabilities,improved enzyme-substrate affinities,and reusabilities.Many studies have been performed to investigate the efficient use of cellulose nanocrystals,polydopamine-based nanomaterials,and synthetic polymer nanogels for enzyme immobilization.Various nanobiocatalysts are highlighted in this review,with the emphasis on the design,preparation,properties,and potential applications of nanoscale enzyme carriers and nanobiocatalysts.
基金Supported by Director Fund for the Year 2008 Project(0806230SZO)Training Projects of Light of Western in Chinese Academy of Sciences(0906040XBO)Chinese Academy of science and Technology Project in Support of Gansu(0806300YDO)~~
文摘[ Objective] The aim was to study the effect of 12C6 ＋ ions beam irradiation to two varieties of sweet sorghum on seed germination and some enzymes activity in seedlings with different doses, and provided a theoretical foundation for sweet sorghum breeding. [ Method] After germination, the germination potential, germination fraction and enzyme activity were detected, respectively. [ Result] The results showed that with the dose increased, the germination potential of sweet sorghum increased first and then decreased, while their germination fraction presented ＂shoulder like shape＂ ; the activity of LDH, SOD, CAT and GSH-Px increased first and then decreased with doses, they presented slight differences among different enzymes. [ Conclusion] Low dose radiation could accelerate germination of sweet sorghum seeds and enzyme activity could remain at a relatively high level. Enzyme activity decreased with high doses and the growth of sweet sorghum was inhibited.
基金Supported by National Science and Technology Support Project(2006BAD07B05)Cooperation Project of Institute of Vegetables and Flowers,Chinese Academy of Agricultural Sciences,with Bei-jing Daxing District(2009-2011)~~
文摘[Objective] The purpose was to study the effects of different arbuscular mycorrhizal fungi strains（AMF）on the mineral nutrition and antioxidant enzymes of Chrysanthemum morifolium.[Method] The pot experiment was conducted in the greenhouse,C.morifolium ＇Jinba＇ was inoculated with five kinds of AMF,N,P,K,malondial dehyde（MDA）content,as well as the superoxide dismutase（SOD）,peroxidase（POD） and catalase（CAT） activity in roots,leaves and petals of C.morifolium were measured at seedling and flowering stages.[Result] The G.i,G.e and G.m treatments could promote mineral nutrient absorption,increase N,P,K content in roots,leaves and petals of C.morifolium compared with the control without inoculation.The G.d、G.e and G.m treatments could significantly reduce MDA content in roots and petals,thus alleviating membrane permeability and lipid peroxidation.The G.i treatments could also improve the SOD,POD and CAT activities of C.morifolium,thereby increasing the capability of scavenging oxygen free radicals.[Conclusion] According to the comprehensive analysis,G.i was screened out as the best strain to improve mineral nutrition and antioxidant enzyme activities of C.morifolium.
文摘The eelgrass ( Zostera marina L.) was treated with artificial seawater (ASW) of different salinities ( 100%, 150% and 200% seawater) for 5 d. The activities of two enzymes extracted from the plant leaves were determined under a salinity grade in vitro So were the photosynthesis rates of the plants from the three treatments in the media with different salinities 100%, 150%, 200%, 300% ASW) and Some physiological data. The data showed that under increased salinities (concentrated seawater), Na+, Cl-, MDA (malon dialdehyde) and glucose contents and the osmotic potentials ( absolute value) in the leaves increased with the salinity elevation in the medium (ASW), but both K+ and free amino acid (mainly proline) contents decreased. Malate dehydrogenase (MDH) from the plant leaves under a salinity grade showed its activities (A) as follows: A(100%) (ASW) > A(150%) (ASW) > A(200%) (ASW). Phosphoenolpyruvate carboxylase (PEPC) extracted from the 100% ASW- and 200% ASW-treated plants showed similar activities (both insensitive to salinities) under the salinity grade in vitro, but the activities of PEPC from plants treated with 150% ASW were dependent oil salinity. Whether the plant is stressed at 150% ASW and can stand higher salinity than seawater needs to be studied further. Meantime, die data do not agree with the opinion that the adaptation of the eelgrass to seawater salinity is partly fulfilled by its insensitiveness to salinities in Some metabolic enzymes. It can be inferred that the lack of transpiration may be an important aspect of tire plant's tolerance to seawater salinity.
文摘The leaves of Bt (Bacillus thuringiensis) transgenic poplar (Populus nigra L.) and CpTI (Cowpea trypsin inhibitor) transgenic poplar ((P. tomentosa×P. bolleana)×P. Tomentosa) were taken to feed the 4th-5th-instar larvae of American white moth (Hyphantria cunea (Drury)) for determination of the activities of the protective enzyme system inside larvae’s body. The physiological and biochemical effects of the transgenic poplars on the larvae were studied. The results showed that the two kinds of transgenic poplars had similar effects on the protective enzyme system in the midgut of larvae. The activities of superoxide dismutase, catalase, and peroxidase in midgut of the larvae increased gradually, reached the highest value at a certain time, and then decreased suddenly. For the larvae that were fed with the leaves of Bt transgenic poplar, the peak value of superoxide dismutase and catalase presented at the time of 24-h feeding, while the peak of peroxidase took place at the time of 12-h feeding. The activities of these protective enzymes for the larvae that were fed with leaves of CpTI transgenic poplar peaked 12 h later than that of those fed with leaves of Bt transgenic poplar. The comparison of activities of the protective enzymes was also carried out between the larvae with different levels of intoxication. It was found that the activities of protective enzyme of the seriously intoxicant larvae were higher than that of the lightly intoxicant larvae. This difference was more obvious in the group treated with CpTI transgenic poplar.
基金Supported by National Natural Science Foundation of China(3044003230771311)+1 种基金Natural Science Foundation of Chongqing City(cstc2009BB1328)Project of Nan'an District Science and Technology Commission of Chongqing City(2008)~~
文摘[Objective] This study aimed to determine activities of antioxidant enzymes during gland morphogenesis in cotton, thoroughly explore physiological changes of cotton and provide a scientific basis for the cultivation of excellent cotton varieties. [Method] Based on determination of gossypol contents and antioxidant enzymes ac- tivities during gland morphogenesis in three cotton varieties （Chuanmian2802, Xiang- mian18 and XianwuN5）, metabolism of gossypol and morphogenesis of gland in cot- ton were explored. [Result] After gland morphogenesis, the content of gossypol in Chuanmian2802 was gradually reduced in the early period of seed germination, which slowly increased since the 5th d after germination; however, during the seed germination period, the content of gossypol in Xiangmian18 had a slowly increasing trend and was gradually close to the content of gossypol in Chuanmian2802. The results showed that activities of SOD, POD and CAT increased in seed germination, which was contributive to remove the superoxide radicals, decrease the peroxide lev- el, reduce damages to the membrane, enhance the body＇s resistance to lipid oxida- tion and increase resistance ability to stress. [Conclusion] This study laid the scientif- ic foundation for understanding the characteristics of gland morphogenesis in cotton and cotton cultivation by using gland traits.
基金Supported by Grapefruit Project under State Forestry(2010-2012[2010]47)Basic Academic Discipline Project of Yunnan Province,Southwest Forestry University[xkz200906]~~
文摘The distribution and ecological characters of grapefruit were analyzed mainly,and the research trends of stock and scion selection for grafting,the healing-anatomy process and enzymology were summarized systematically.The results indicated that the range of stock and scion apolegamy decreased through the application of molecular technique.But the study on stock variety and scion selection was still in need of expanding and the key enzyme played a vital role in the healing of the stock and scion,which provided a chance for the regulation and control of healing force by hormones and also provided a theoretical basis for the regulation of gene.
文摘[Objective] The aim was to understand defense mechanism of pear after inoculated Botryosphaeria berengeriana f. sp. piricolan and mechanism of antioxidant enzymes of biocontrol bacteria. [Method] Pears were treated by Botryosphaeria berengeriana f. sp. piricolan and bio control bacteria, and the change of antioxidant enzymes were determined. [Result] The biocontrol bacteria had little effect on MDA;the content of MDA treated by B. berengeriana reached high peak in 48 h, was 10.22nmol/g which was 1.86 times of CK; the content of MDA treated by B. berengeriana and biocontrol bacteria reached high peak in 24 h, was 8.92 nmol/g which was1.62 times of CK. The content of SOD treated by biocontrol bacteria reached high peak in 48 h, was 126.69 U/[g（FW）·min] which was 1.54 times of CK; the contents of SOD treated by B. berengeriana as well as B. berengeriana and biocontrol bacteria reached high peak in 24 h, were 122.10 and 135.32 U/[g（FW）·min] which were 1.48 and 1.65 times of CK respectively; the contents of POD on biocontrol bacteria treatment, B. ana treatment as well as B. berengeriana and biocontrol bacteria treatment reached high peak in 24 h, were 385.34, 342.50 and 290.00 U/[g（FW）·min] which were 1.83, 1.62 and 1.38 times of CK respectively. The contents of CAT on biocontrol bacteria treatment, B. rengeriana treatment as well as B. berengeriana and biocontrol bacteria treatment reached high peak in 6 h, were 133.33,114.17 and 113.35 U/[g（FW）·min] which were 1.33, 1.14 and 1.13 times of CK respectively. The biocontrol bacteria had little difference in CK; the content of PPO of B. berengeriana treatment reached high peak in 12 h, was 81.86 U/[g（FW）·min]which was 1.76 times of CK; B. berengeriana and biocontrol bacteria treatment reached high peak in 24 h, was 70.00 U/[g（FW）·min] which was 1.50 times of CK.[Conclusion] B. berengeriana and biocontrol bacteria had more effect on MDA; both B. berengeriana and biocontrol bacteria could increase the excitation of SOD enzyme activity; both B. berengeriana and biocontrol bacteria could increase the excitation of POD enzyme activity; both B. berengeriana and biocontrol bacteria could increase the excitation of CAT enzyme activity; using biocontrol bacteria alone had not obvious effect on PPO, B. berengeriana could increase the excitation of PPO enzyme activity.
基金National Basic Research Program(973 Program,Grant No.2004CB518904).
文摘The 3＇-OH, 4＇-OH and 2＂-OH of kanamycin A were modified in search of new aminoglycosides to overcome resistant enzymes, ANTs and APHs. The key intermediate was a dibenzylidene-protected derivative of kanamycin A. The aimed sites were masked by benzyl, methyl and allyl groups. Multi-step reactions gave the desired aminoglycoside derivatives but showed less antibiotic activity than kanamycin A.
基金Supported by Research Fund of the State Tobacco Monopoly Bureau(110201002002)the Open Research Project of Key Laboratory of Tobacco Genetics and Breeding in the Tobacco Industry(TB201006)~~
文摘[Objective] This study aimed to explore the effects of spores and crude toxins of Helminthosporium gramineum Rabenh f. sp. echinochloae（HGE） on the ac- tivity of defensive enzymes of barnyardgrass [Echinochloa crus-galli （L.） Beauv.]. [Method] The effects of spores and crude toxins of HGE, as well as the mixture of spores and crude toxins on the activity of defensive enzymes in barnyardgrass were determined under laboratory conditions. [Result] Spores and crude toxins of HGE had varying degrees of effects on PAL and POD activity, and no obvious effect on SOD activity in barnyardgrass. In addition, spores and toxins had some similar im- pacts on the defensive enzymes in barnyardgrass. [Conclusion] Since toxins have similar effects on the hosts as spores of fungal pathogen do, they can be a substi- tute for the fungal pathogen in studying the partial pathogenic mechanism of this pathogen due to its complexity in pathogenic process.
