Food-derived polysaccharides are gaining popularity across diverse food applications due to their wideranging bioactivities and distinctive properties.The specific targeting of glycoside hydrolases towards glycosidic ...Food-derived polysaccharides are gaining popularity across diverse food applications due to their wideranging bioactivities and distinctive properties.The specific targeting of glycoside hydrolases towards glycosidic bonds lays the groundwork for synthesizing and exploring specific structural segments of polysaccharides,offering crucial implications in the food industry.However,macromolecular polysaccharides demonstrate limited biological activities as their active centers are tightly enveloped,posing challenges for traversing cell membrane barriers.By selectively cleaving partial glycosidic linkages in polysaccharides,glycoside hydrolases decrease the polymerization of polysaccharide molecules and effectively change the structural characteristics,where a series of smaller polysaccharide fragments can be generated for improving the bioactivities and properties in some respects.This review examines the role of glycoside hydrolases in degrading food-derived polysaccharides,the structure-function relationships,reaction conditions,and the current application status of degraded polysaccharides is discussed in particular.In addition,we also highlight challenges and future directions worth attention in the application of enzymes and polysaccharides.Overall,the present review will provide an efficient method for producing bioactivity-enhanced polysaccharides,which can improve the effectiveness and safety of functional foods to safeguard human wellness.展开更多
In a genome the set of proteins are formed by duplication and combination of domain superfamilies. P-loop containing nucleotide triphosphate （NTP） hydrolases superfamily is massively duplicated and has the most diff...In a genome the set of proteins are formed by duplication and combination of domain superfamilies. P-loop containing nucleotide triphosphate （NTP） hydrolases superfamily is massively duplicated and has the most different partner superfamilies among archaea, bacteria and eukarya, Here, we study the distributions of duplication and combination of p-loop containing NTP hydrolases superfamily in 169 completed genomes. When the total number of domains in a genome is larger, duplication and combination partners of p-loop conraining NTP hydrolases are more. This phenomenon is more obvious in metazoa. The distributions of abundance and corn bination of partners relate to the functions of the protein. Those distributions in metazoa are very different from those in other kingdoms because of complexity of metazoa. Finally the relationship between duplication and combination of p-loop containing NTP hydrolases superfamily in different genomes is described. It fits a power law.展开更多
A two-layer method based on support vector machines (SVMs) has been developed to distinguish epoxide hydrolases (EHs) from other enzymes and to classify its subfamilies using its primary protein sequences. SVM classif...A two-layer method based on support vector machines (SVMs) has been developed to distinguish epoxide hydrolases (EHs) from other enzymes and to classify its subfamilies using its primary protein sequences. SVM classifiers were built using three different feature vectors extracted from the primary sequence of EHs: the amino acid composition (AAC), the dipeptide composition (DPC), and the pseudo-amino acid composition (PAAC). Validated by 5-fold cross tests, the first layer SVM clas- sifier can differentiate EHs and non-EHs with an accuracy of 94.2% and has a Matthew’s correlation coefficient (MCC) of 0.84. Using 2-fold cross validation, PAAC-based second layer SVM can further classify EH subfamilies with an overall accuracy of 90.7% and MCC of 0.87 as compared to AAC (80.0%) and DPC (84.9%). A program called EHPred has also been developed to assist readers to recognize EHs and to classify their subfamilies using primary protein sequences with greater accuracy.展开更多
The epididymal epithelia, by secretion, fluid reabsorption and transition, provide a favorable environment for sperm maturation. We observed, with histochemical method, the regional differences of four hydrolases and ...The epididymal epithelia, by secretion, fluid reabsorption and transition, provide a favorable environment for sperm maturation. We observed, with histochemical method, the regional differences of four hydrolases and five dehydrogenases in caput, corpus and cauda of rat epididymis展开更多
[Objective] This study aimed to isolate an acidophilic fungus and analyze the acidophilic enzymes secreted by this fungus. [Method] A heterotrophic fungus was isolated from the leaching solution of a uranium ore in Ji...[Objective] This study aimed to isolate an acidophilic fungus and analyze the acidophilic enzymes secreted by this fungus. [Method] A heterotrophic fungus was isolated from the leaching solution of a uranium ore in Jiangxi Province using oligotrophic acid selective medium （pH 2.5）, and was named RBS-6. This strain was then identified according to its colony morphology and molecular indicator rDNA-ITS. Finally, the glycoside hydrolases secreted by RBS-6 were analyzed. [Result] This fungus RBS-6 was acidophilic, and grew best at pH4.0. Its rDNA-ITS sequence shared the highest homology （98%） with that of Phialophora sp. CGMCC 3329 （GU 082377）. So it was identified as a fungus of Phialophora sp., and was temporarily named as Phialophora sp. RBS-6. It can produce six glycoside hydrolases, in cluding α-galactosidase glucosidase, β-glucosidase, β-mannanase and β-glucanase. All the enzymes were acidophilic, for which the optimum reaction pH was 3.0-4.0. Among them, β-glucanase exhibited the highest activity at pH 3.5 and 50 ℃; in addition, it was heat-stable as 58% of the enzyme activity was remained after incubation at 50 ℃ for 60 min. [Conclusion] The isolated fungus which was identified as an acidophilic member of Phialophora sp., was a new strain producing acidophilic enzymes. This study supplied new data for the research on Phialophora fungi.展开更多
UDP-glucose hydrolases are a group of relatively little known membrane-bound or periplasmic enzymes found in Salmonella enterica and E. coli. UDP-glucose is an agonist for a specific P2 receptor (P2Y14) found on epith...UDP-glucose hydrolases are a group of relatively little known membrane-bound or periplasmic enzymes found in Salmonella enterica and E. coli. UDP-glucose is an agonist for a specific P2 receptor (P2Y14) found on epithelial cells and cells associated with innate immunity. It is also recognised as a ‘danger signal’. Cells respond to mechanical damage by releasing UDP-glucose which activates P2Y14 to trigger an innate immune response;it is postulated that a similar response to bacterial infection may be protective against infection. However, the UDP-glucose hydrolases may constitute virulence factors able to abrogate this response by degradation of the released UDP-glucose.展开更多
Polyethylene terephthalate(PET),a synthetic polyester that is widely used in packaging,textiles,and bottles,poses a significant environmental challenge because of its resistance to biodegradation.
Microplastics provide a new ecological niche for microorganisms,and the accumulation levels of microplastics(MPs)in terrestrial ecosystems are higher than those in marine ecosystems.Here,we applied the zymography to i...Microplastics provide a new ecological niche for microorganisms,and the accumulation levels of microplastics(MPs)in terrestrial ecosystems are higher than those in marine ecosystems.Here,we applied the zymography to investigate how MPs–polyethylene[PE],and polyvinyl chloride[PVC])at two levels(0.01%and 1%soil weight)impacted the spatial distribution of soil hydrolases,nutrient availability,and rice growth in paddy soil.MPs increased the above-ground biomass by 13.0%–15.5%and decreased the below-ground biomass by 8.0%–15.1%.Addition of 0.01%and 1%MPs reduced soil NH4+content by 18.3%–63.2%and 52.2%–80.2%,respectively.The average activities of N-and P-hydrolases increased by 0.8%–4.8%and 1.9%–6.3%with addition of MPs,respectively.The nutrient uptake by rice plants and the enzyme activities in hotspots increased with MP content in soil.The accumulation of MPs in paddy soil could provide an ecological niche that facilitates microbial survival,alters the spatial distribution of soil hydrolases,and decreases nutrient availability.展开更多
Soil organic carbon in forest affects nutrient availability,microbial processes,and organic matter inputs.Dominant tree species have increasingly shifted from ectomycorrhizal to arbuscular mycorrhizal associations in ...Soil organic carbon in forest affects nutrient availability,microbial processes,and organic matter inputs.Dominant tree species have increasingly shifted from ectomycorrhizal to arbuscular mycorrhizal associations in subtropical forests.However,the consequences of this shift for soil organic carbon is poorly understood.To address this,a field study was conducted across a natural gradient of arbuscular tree associations to investigate how different mycorrhizal associations affect soil organic carbon quantity,composition,chemical stability,and related soil properties.Soil organic carbon fractions,functional groups,microbial enzyme activities were analyzed.Results showed that increasing arbuscular mycorrhizal dominance was associated with declines in total soil organic carbon,particularly in recalcitrant and aromatic carbon forms.Ectomycorrhizaldominated forests exhibited higher nitrogen availability and elevated nitrogen-hydrolyzing enzyme activity,suggesting enhanced nitrogen acquisition strategies that suppress soil organic carbon decomposition and promote carbon retention.These findings indicate that mycorrhizal-mediated shifts in tree composition may significantly alter soil carbon sequestration potential.Incorporating mycorrhizal functional traits into forest management and carbon modeling could improve predictions of soil organic carbon responses under future environmental change.展开更多
The trend of employing machine learning methods has been increasing to develop promising biocatalysts.Leveraging the experimental findings and simulation data,these methods facilitate enzyme engineering and even the d...The trend of employing machine learning methods has been increasing to develop promising biocatalysts.Leveraging the experimental findings and simulation data,these methods facilitate enzyme engineering and even the design of new-to-nature enzymes.This review focuses on the application of machine learning methods in the engineering of polyethylene terephthalate(PET)hydrolases,enzymes that have the potential to help address plastic pollution.We introduce an overview of machine learning workflows,useful methods and tools for protein design and engineering,and discuss the recent progress of machine learning-aided PET hydrolase engineering and de novo design of PET hydrolases.Finally,as machine learning in enzyme engineering is still evolving,we foresee that advancements in computational power and quality data resources will considerably increase the use of data-driven approaches in enzyme engineering in the coming decades.展开更多
Nitrogen(N)enrichment has resulted in widespread alteration of grassland ecosystem processes and functions mainly through disturbance in soil enzyme activities.However,we lack a comprehensive understanding of how N de...Nitrogen(N)enrichment has resulted in widespread alteration of grassland ecosystem processes and functions mainly through disturbance in soil enzyme activities.However,we lack a comprehensive understanding of how N deposition affects specific key soil enzymes that mediate plant-soil feedback of grassland.Here,with a meta-analysis on 1446 cases from field observations in China,we show that N deposition differently affects soil enzymes associated with soil biochemical processes.Specifically,N-promoted C,N,and P-acquiring hydrolase activities significantly increased by 8.73%,7.67%,and 8.69%,respectively,related to an increase in microbial-specific enzyme secretion.The increased relative N availability and soil acidification were two potential mechanisms accounting for the changes in soil enzyme activities with N enrichment.The mixed N addition in combination of NH_(4)NO_(3) and urea showed greater stimulation effect on soil enzyme activities.However,the high rate and long-term N addition tended to weaken the positive responses of soil C-,Nand P-acquiring hydrolase activities to N enrichment.Spatially increased mean annual precipitation and temperature primarily promoted the positive effects of N enrichment on N-and P-acquiring hydrolase activities,and the stimulation of C-and N-acquiring hydrolase activities by N enrichment was intensified with the increase in soil depth.Finally,multimodal inference showed that grassland type was the most important regulator of responses of microbial C,N,and P-acquiring hydrolase activities to N enrichment.This meta-analysis provides a comprehensive insight into understanding the key role of N enrichment in shaping soil enzyme activities of grassland ecosystems.展开更多
The current study deals with cloning and expressing a maltogenic α-amylase gene from thermophilic Bacillus stercoris YSP18(AmyYSP)in Escherichia coli BL21(DE3).AmyYSP belongs to the GH13_20 subfamily of Glycoside Hyd...The current study deals with cloning and expressing a maltogenic α-amylase gene from thermophilic Bacillus stercoris YSP18(AmyYSP)in Escherichia coli BL21(DE3).AmyYSP belongs to the GH13_20 subfamily of Glycoside Hydrolases and entails five conserved regions found in maltogenic α-amylases.As a monomer of 67 kDa,AmyYSP exhibits maximal activity at 80℃,pH 5.0 and retains>75%residual activity at 70-100℃ and pH 5.0-8.0.The kinetic and thermodynamic studies displayed that it has a high affinity for soluble starch(K_(m)=1.54±0.236 mgmL^(−1)),exhibits a longer half-life(38.5 h at 80℃ and 8.88 h at 100℃),and a higher EaD value of 3824±1.03 kJ mol^(−1).It was characterised as a Ca^(2+)-independent α-amylase,resistant to various denaturing additives.It hydrolyses soluble starch and raw corn starch efficiently,liberating glucose,maltose,maltotriose and maltotetraose as the main products.The thermostable and acid-stable,maltooligosaccharide forming AmyYSP is a versatile enzyme with prerequisites for successful application in starch-saccharification industries.展开更多
[Objective] This study aimed to investigate the functions and related mechanisms of xyloglucan Endotransglycosylase/hydrolases （XTHs） during the growth and development of dahlia. [Method] Using /3-actin as the refer...[Objective] This study aimed to investigate the functions and related mechanisms of xyloglucan Endotransglycosylase/hydrolases （XTHs） during the growth and development of dahlia. [Method] Using /3-actin as the reference gene, the rela- tive transcription levels of DpXTH1 and DpXTH2 genes in roots, stems, leaves and petals of dahlia were analyzed by real-time RT-PCR. [Result] The DpXTH1 and DpXTH2 were not expressed in the roots, but expressed abundantly in the petals of dahlia. There were little expressions in the stems and leaves of dahlia. [Conclusion] The DpXTH1 and DpXTH2 were petal-specific genes and closely related to the growth and development of petals in dahlia.展开更多
Plant pathogens secrete various cell wall-degrading enzymes that compromise host cell wall integrity and facilitate pathogen invasion.This study identified VdGH7a,a glycoside hydrolase family 7(GH7)cellobiohydrolase f...Plant pathogens secrete various cell wall-degrading enzymes that compromise host cell wall integrity and facilitate pathogen invasion.This study identified VdGH7a,a glycoside hydrolase family 7(GH7)cellobiohydrolase from Verticillium dahliae,which demonstrated hydrolytic activity against 1,4-β-glucan.Notably,VdGH7a induced cell death in Nicotiana benthamiana when signal peptides were present,though this effect was inhibited by the carbohydrate-binding type-1(CBM1)protein domain.The deletion of VdGH7a substantially reduced V.dahliae pathogenicity in cotton plants,as demonstrated by the mutants’inability to penetrate cellophane membrane.These knockout mutants also exhibited reduced carbon source utilization capacity and increased sensitivity to osmotic and cell wall stresses.Through yeast two-hybrid screening,bi-molecular fluorescence complementation(BiFC),and luciferase complementation imaging(LCI),we identified that VdGH7a interacts with an osmotin-like protein(GhOLP1)in cotton.Virus-induced gene silencing of GhOLP1 resulted in decreased salicylic acid(SA)content and reduced resistance to V.dahliae in cotton,while heterologous overexpression of GhOLP1 in Arabidopsis enhanced both resistance and SA signaling pathway gene expression.These results reveal a virulence mechanism wherein the secreted protein VdGH7a from V.dahliae interacts with GhOLP1 to activate host immunity and contribute significantly to plant resistance against V.dahliae.展开更多
Camptothecin,a plant-derived pentacyclic pyrroloquinoline alkaloid,and its derivatives like topotecan and irinotecan have been used as clinical anticancer agents for decades.However,the complete biosynthetic pathway o...Camptothecin,a plant-derived pentacyclic pyrroloquinoline alkaloid,and its derivatives like topotecan and irinotecan have been used as clinical anticancer agents for decades.However,the complete biosynthetic pathway of camptothecin still remains unelucidated due to the unknown complex formation processes and corresponding enzymes for the downstream biosynthetic pathway including the committed hydrolysis of glycosides.Herein,a novel glycoside hydrolase(CaGH1)responsible for the deglycosylation of biosynthetic glycoside intermediates including both quinoline-type alkaloids pumiloside(1),(3S)-deoxypumiloside(2)and indole-type alkaloid strictosamide(3)has been functionally identified.Moreover,CaGH1 exhibits the highly strict stereoselectivity towards the substrates with 3S configuration.Furthermore,a combined strategy for the discovery of the unknown biosynthetic enzyme by employing activity-guided enzyme verification,transcriptome-based gene mining,biochemical assay in vitro,and structurally characterizing the unstable enzymatic products by derivatization,is reported.These findings not only provide a better understanding of the deglycosylation in camptothecin biosynthesis,also lay the foundation for the complete elucidation of camptothecin biosynthetic pathway and biological production of camptothecin.展开更多
Trehalose is a widely used and safe natural disaccharide.Maltooligosyl trehalose hydrolase(MTHase)is one of the key enzymes for trehalose preparation by double enzyme method using starch or dextrin as substrate.In ind...Trehalose is a widely used and safe natural disaccharide.Maltooligosyl trehalose hydrolase(MTHase)is one of the key enzymes for trehalose preparation by double enzyme method using starch or dextrin as substrate.In industrial production,the thermalstability of MTHase is of great significance.We first heterogeneously expressed MTHase from Arthrobacter in E.coli strains BL21(DE3).Based on the overall stability of the protein after virtual saturation mutation predicted by FoldX and the evolutionary information from PSSM,15 mutations were selected and combined.Finally,the combinatorial mutant G589P/A57P was obtained.At 60℃,the t_(1/2)of G589P/A57P and wild type are 37 min and 19 min,respectively,which is 1.9 times higher than that of wild type.The enzyme kinetic parameters of G589P/A57P were analyzed.The K_(M)and k_(cat)are 4.82 mM and 1136 s^(−1),respectively,and the results were close to the wild type,indicating that the mutation did not reduce the catalytic efficiency of the enzyme.The molecular dynamics simulation results show that the rigidity and thermal stability of G589P/A57P protein increase in the range of residues 50-100 and 400-500,which may be due to the proline effect caused by the introduction of proline.展开更多
Objective:Soluble epoxide hydrolase(sEH)emerges as a target of interest for inflammatory diseases.Piperine is a natural amide alkaloid from Piper nigrum and displays an inhibitory effect toward sEH,its chemical struct...Objective:Soluble epoxide hydrolase(sEH)emerges as a target of interest for inflammatory diseases.Piperine is a natural amide alkaloid from Piper nigrum and displays an inhibitory effect toward sEH,its chemical structural transformation was carried out in order to obtain a library of sEH inhibitors based on its skeleton.Methods:Structural transformation of piperine was carried out by chemical methods,and piperine derivatives were assayed for their sEH potentials.A mouse acute lung injury model was constructed by lipopolysaccharide(LPS).Hematoxylin and eosin(H&E)staining,immunofluorescence staining,Western Blot,and enzyme-linked immunosorbent assay were used for investigating the protective potential of sEH inhibitor 11h.Results:Piperine derivatives 11e,11h,11j,and 11o showed inhibitory potentials toward sEH with values of half maximal inhibitory concentration(IC50)from 20 to 70 nM.Compound 11h attenuated the pathological course of LPS-mediated acute lung injury(ALI)in vivo.Furthermore,levels of cytokines tumor necrosis factor alpha(TNF-α),interleukin 6(IL-6),myeloperoxidase(MPO),and lactate dehydrogenase(LDH)were decreased after administration of 11h.The LPS-mediated inflammation and redox unbalance,including expressions of cyclooxygenase-2(COX-2),heme oxygenase-1(HO-1),intercellular cell adhesion molecule-1(ICAM-1),vascular cell adhesion molecule-1(VCAM-1),p-p65/p65,glutamate-cysteine ligase modifier subunit(GCLM),and nuclear factor erythroid-2-related factor 2(Nrf2),were ameliorated through nuclear factor kappa B(NF-κB)and Nrf2 pathways via enhancing levels of epoxyeicosatrienoic acids(EETs)in LPS-exposed ALI mice after compound 11h treatment.Molecular docking demonstrated that the aromatic unsaturated group of 11h occupied a hydrophobic pocket and its urea group formed three hydrogen bonds with Asp333,Tyr381,and Tyr465,which stabilized the active conformation of the ligand.Conclusions:These findings demonstrated that compound 11h may serve as a lead compound for developing sEH inhibitors and treating inflammation related to diseases,such as ALI.展开更多
Background Body weight is an important indicator of the overall health and production efficiency in broiler chickens.In broiler houses,body weight of chicks is variable despite the same genetics,hatching and feeding p...Background Body weight is an important indicator of the overall health and production efficiency in broiler chickens.In broiler houses,body weight of chicks is variable despite the same genetics,hatching and feeding practices within a production system.The objective of this study was to investigate the intestinal microbiota and bile salt hydrolase(BSH)activity in slow and fast growing broiler chickens,which belonged to the 10th and 90th percentile body weight groups,respectively.Methods A total of 300 Ross 308 broiler chickens(100 per cohort from three independent cohorts)were selected and mucosal samples from the jejunum,ileum,and cecum were collected at day of arrival,11 and 25(n=450).Then,bacterial counts,16S rRNA amplicon sequencing,species specific real-time qPCR,as well as BSH activity were analyzed.Results Results of bacterial counts showed no significant difference between slow and fast growing cohorts(P>0.05),but they tended to be higher in the slow growing chickens in all measured bacterial groups in cecum.The 16S rRNA amplicon sequencing revealed higher relative abundance of E.coli-Shigella(71.3%−79.8%)at day of arrival,while the most abundant microorganisms at d 25 was Candidatus Arthromitus(slow:44.5%;fast:27.4%)in small intestine.qPCR results indicated significant differences in bacterial populations between the slow and fast growing chickens,especially higher total bacteria,Enterococcus,and Clostridium cluster I in the slow growing chickens at d 25.BSH activity was higher in the slow growing chickens than the fast growing chickens[slow:0.476ΔOD/protein(μg/mL);fast:0.258ΔOD/protein(μg/mL);P<0.0001],and correlation analysis highlighted associations between BSH activity,body weight,feed intake,body weight gain,and bacterial counts.Conclusions We postulate that high total bacteria and Enterococcus abundance are associated with high BSH activity,impacting low feed intake and body weight gain,ultimately resulting in separation into slow and fast growing birds.The findings of this study contribute to understanding the relationship between gut microbiota,BSH activity,and host physiology in broiler chickens,with potential implications for poultry production.展开更多
Soil enzymes activities and microbial biomass have an important influence on nutrient cycling. The spatial distribution of soil enzymes activities and microbial biomass were examined along a latitudinal gradient in fa...Soil enzymes activities and microbial biomass have an important influence on nutrient cycling. The spatial distribution of soil enzymes activities and microbial biomass were examined along a latitudinal gradient in farmlands of Songliao Plain, Northeast China to assess the impact of climatic changes along the latitudinal transect on nutrient cycling in agroecosystems. Top soils （0-20 cm depth） were sampled in fields at 7 locations from north （Hallun） to south （Dashiqiao） in the end of October 2005 after maize harvest. The contents of total C, N, and P, C/N, available N, and available P increased with the latitude. The activities of invertase and acid phosphatase, microbial biomass （MB） C and N, and MBC/MBN were significantly correlated with latitude （P 〈 0.05, r^2 = 0.198, 0.635, 0.558, 0.211 and 0.317, respectively）, that is, increasing with the latitude. Significant positive correlations （P 〈 0.05） were observed between invertase activity and the total N and available P, and between acid phosphatase activity and the total C, C/N, available N, total P and available P. The urease, acid phosphatase, and dehydrogenase activities were significantly correlated with the soil pH and electrical conductivity （EC） （P 〈 0.05）. MBC and MBN were positively correlated with the total C, C/N, and available P （P 〈 0.05）. The MBC/MBN ratio was positively correlated with the total C, total N, C/N, and available N （P 〈 0.05）. The spatial distribution of soil enzyme activities and microbial biomass resulted from the changes in soil properties such as soil organic matter, soil pH, and EC, partially owing to variations in temperature and rainfall along the latitudinal gradient.展开更多
AIM:To determine the association of hOGG1 (8-oxoguanine glycosylase I,OGG1) polymorphism of Ser326Cys substitution with colon cancer risk and possible interaction with known environmental risk factors. METHODS:A case-...AIM:To determine the association of hOGG1 (8-oxoguanine glycosylase I,OGG1) polymorphism of Ser326Cys substitution with colon cancer risk and possible interaction with known environmental risk factors. METHODS:A case-control study with 125 colon cancer cases and 247 controls was conducted, RESULTS:There was no major difference in Ser326Cys genotype distribution between cases and controls.The meat intake tended to increase the odds ratio for colon cancer with an OR of 1.72 (95 % confidence interval;CI=1.12-2.76). Such tendency was more prominent in Cys/Cys carriers (OR=4.31,95 % CI=1.64-11.48),but meat intake was not a significant risk factor for colon cancer in Ser/Ser or Ser/ Cys carriers.The OR for colon cancer was elevated with marginal significance in smokers who were Cys/Cys carriers (OR=2.75,95 % CI=1.07-7.53) but not in Ser/Ser or Ser/ Cys carriers. CONCLUSION:These results suggest that the hOGG1 Ser326Cys polymorphism is probably not a major contributor to individual colon cancer susceptibility overall,but the Cys/ Cys genotype may alter the impact of some environmental factors on colon cancer development.展开更多
基金supported by the Jiangsu Province University Basic Science(Natural Science)Research Major Project(24KJA360007)Nanjing University of Chinese Medicine TCM First-Class Discipline"Leading Plan"Scientific Research Project(ZYXYL2024-001)+3 种基金Jiangsu Provincial TCM Science and Technology Development Program Project(MS2021004)High Level Key Discipline Construction Project of the National Administration of Traditional Chinese Medicine-Resource Chemistry of Chinese Medicinal Materials(ZYYZDXK-2023083)National Administration of Traditional Chinese Medicine Chinese Medicine Innovation Team and Talent Support Program Project(ZYYCXTD-D-202005)2022 Student Innovation Training Program Project(103152022075).
文摘Food-derived polysaccharides are gaining popularity across diverse food applications due to their wideranging bioactivities and distinctive properties.The specific targeting of glycoside hydrolases towards glycosidic bonds lays the groundwork for synthesizing and exploring specific structural segments of polysaccharides,offering crucial implications in the food industry.However,macromolecular polysaccharides demonstrate limited biological activities as their active centers are tightly enveloped,posing challenges for traversing cell membrane barriers.By selectively cleaving partial glycosidic linkages in polysaccharides,glycoside hydrolases decrease the polymerization of polysaccharide molecules and effectively change the structural characteristics,where a series of smaller polysaccharide fragments can be generated for improving the bioactivities and properties in some respects.This review examines the role of glycoside hydrolases in degrading food-derived polysaccharides,the structure-function relationships,reaction conditions,and the current application status of degraded polysaccharides is discussed in particular.In addition,we also highlight challenges and future directions worth attention in the application of enzymes and polysaccharides.Overall,the present review will provide an efficient method for producing bioactivity-enhanced polysaccharides,which can improve the effectiveness and safety of functional foods to safeguard human wellness.
基金Supported by the National Natural Science Foun-dation of China (10374072)
文摘In a genome the set of proteins are formed by duplication and combination of domain superfamilies. P-loop containing nucleotide triphosphate （NTP） hydrolases superfamily is massively duplicated and has the most different partner superfamilies among archaea, bacteria and eukarya, Here, we study the distributions of duplication and combination of p-loop containing NTP hydrolases superfamily in 169 completed genomes. When the total number of domains in a genome is larger, duplication and combination partners of p-loop conraining NTP hydrolases are more. This phenomenon is more obvious in metazoa. The distributions of abundance and corn bination of partners relate to the functions of the protein. Those distributions in metazoa are very different from those in other kingdoms because of complexity of metazoa. Finally the relationship between duplication and combination of p-loop containing NTP hydrolases superfamily in different genomes is described. It fits a power law.
基金Project (No. 20542006) supported by the National Natural ScienceFoundation of China
文摘A two-layer method based on support vector machines (SVMs) has been developed to distinguish epoxide hydrolases (EHs) from other enzymes and to classify its subfamilies using its primary protein sequences. SVM classifiers were built using three different feature vectors extracted from the primary sequence of EHs: the amino acid composition (AAC), the dipeptide composition (DPC), and the pseudo-amino acid composition (PAAC). Validated by 5-fold cross tests, the first layer SVM clas- sifier can differentiate EHs and non-EHs with an accuracy of 94.2% and has a Matthew’s correlation coefficient (MCC) of 0.84. Using 2-fold cross validation, PAAC-based second layer SVM can further classify EH subfamilies with an overall accuracy of 90.7% and MCC of 0.87 as compared to AAC (80.0%) and DPC (84.9%). A program called EHPred has also been developed to assist readers to recognize EHs and to classify their subfamilies using primary protein sequences with greater accuracy.
文摘The epididymal epithelia, by secretion, fluid reabsorption and transition, provide a favorable environment for sperm maturation. We observed, with histochemical method, the regional differences of four hydrolases and five dehydrogenases in caput, corpus and cauda of rat epididymis
基金Supported by Manufacture - Learning - Research Cooperation Project of Education Department of Jiangxi Province(GJJ09008)Nuclear Power Development Projects [COSTIND, (2009)1230]~~
文摘[Objective] This study aimed to isolate an acidophilic fungus and analyze the acidophilic enzymes secreted by this fungus. [Method] A heterotrophic fungus was isolated from the leaching solution of a uranium ore in Jiangxi Province using oligotrophic acid selective medium （pH 2.5）, and was named RBS-6. This strain was then identified according to its colony morphology and molecular indicator rDNA-ITS. Finally, the glycoside hydrolases secreted by RBS-6 were analyzed. [Result] This fungus RBS-6 was acidophilic, and grew best at pH4.0. Its rDNA-ITS sequence shared the highest homology （98%） with that of Phialophora sp. CGMCC 3329 （GU 082377）. So it was identified as a fungus of Phialophora sp., and was temporarily named as Phialophora sp. RBS-6. It can produce six glycoside hydrolases, in cluding α-galactosidase glucosidase, β-glucosidase, β-mannanase and β-glucanase. All the enzymes were acidophilic, for which the optimum reaction pH was 3.0-4.0. Among them, β-glucanase exhibited the highest activity at pH 3.5 and 50 ℃; in addition, it was heat-stable as 58% of the enzyme activity was remained after incubation at 50 ℃ for 60 min. [Conclusion] The isolated fungus which was identified as an acidophilic member of Phialophora sp., was a new strain producing acidophilic enzymes. This study supplied new data for the research on Phialophora fungi.
文摘UDP-glucose hydrolases are a group of relatively little known membrane-bound or periplasmic enzymes found in Salmonella enterica and E. coli. UDP-glucose is an agonist for a specific P2 receptor (P2Y14) found on epithelial cells and cells associated with innate immunity. It is also recognised as a ‘danger signal’. Cells respond to mechanical damage by releasing UDP-glucose which activates P2Y14 to trigger an innate immune response;it is postulated that a similar response to bacterial infection may be protective against infection. However, the UDP-glucose hydrolases may constitute virulence factors able to abrogate this response by degradation of the released UDP-glucose.
基金supported by the National Key R&D Program of China(Grant No.2024YFC3407100)National Natural Science Foundation of China(Grant No.32200081)Young Taishan Scholars Program of Shandong Province(Grant No.tsqn202312029).
文摘Polyethylene terephthalate(PET),a synthetic polyester that is widely used in packaging,textiles,and bottles,poses a significant environmental challenge because of its resistance to biodegradation.
基金We are grateful for financial support from the National Key Research and Development Plan(2019YFC1805100)the National Natural Science Foundation of China(42107341,21767012)+2 种基金the UK Natural Environment Research Council and the Global Challenges Research Fund(NE/V005871/1)sponsorship by K.C.Wong Magna Fund in Ningbo Universitythe Science and Technology Plan of Ganzhou City(GSKF201850).
文摘Microplastics provide a new ecological niche for microorganisms,and the accumulation levels of microplastics(MPs)in terrestrial ecosystems are higher than those in marine ecosystems.Here,we applied the zymography to investigate how MPs–polyethylene[PE],and polyvinyl chloride[PVC])at two levels(0.01%and 1%soil weight)impacted the spatial distribution of soil hydrolases,nutrient availability,and rice growth in paddy soil.MPs increased the above-ground biomass by 13.0%–15.5%and decreased the below-ground biomass by 8.0%–15.1%.Addition of 0.01%and 1%MPs reduced soil NH4+content by 18.3%–63.2%and 52.2%–80.2%,respectively.The average activities of N-and P-hydrolases increased by 0.8%–4.8%and 1.9%–6.3%with addition of MPs,respectively.The nutrient uptake by rice plants and the enzyme activities in hotspots increased with MP content in soil.The accumulation of MPs in paddy soil could provide an ecological niche that facilitates microbial survival,alters the spatial distribution of soil hydrolases,and decreases nutrient availability.
基金supported by the National Natural Science Foundation of China(grant numbers 32471851,32171759 and 32201533)Double Thousand Plan of Jiangxi Province(jxsq2023201058)Jiangxi Province Ganpo Juncai Support Plan(2024BCE50043).
文摘Soil organic carbon in forest affects nutrient availability,microbial processes,and organic matter inputs.Dominant tree species have increasingly shifted from ectomycorrhizal to arbuscular mycorrhizal associations in subtropical forests.However,the consequences of this shift for soil organic carbon is poorly understood.To address this,a field study was conducted across a natural gradient of arbuscular tree associations to investigate how different mycorrhizal associations affect soil organic carbon quantity,composition,chemical stability,and related soil properties.Soil organic carbon fractions,functional groups,microbial enzyme activities were analyzed.Results showed that increasing arbuscular mycorrhizal dominance was associated with declines in total soil organic carbon,particularly in recalcitrant and aromatic carbon forms.Ectomycorrhizaldominated forests exhibited higher nitrogen availability and elevated nitrogen-hydrolyzing enzyme activity,suggesting enhanced nitrogen acquisition strategies that suppress soil organic carbon decomposition and promote carbon retention.These findings indicate that mycorrhizal-mediated shifts in tree composition may significantly alter soil carbon sequestration potential.Incorporating mycorrhizal functional traits into forest management and carbon modeling could improve predictions of soil organic carbon responses under future environmental change.
基金This work was supported by the National Natural Science Foundation of China under grant number 32371325the Seed Funding of China Petrochemical Corporation(Sinopec Group)under grant number 223260the Fundamental Research Funds for the Central Universities(QNTD2023-01).
文摘The trend of employing machine learning methods has been increasing to develop promising biocatalysts.Leveraging the experimental findings and simulation data,these methods facilitate enzyme engineering and even the design of new-to-nature enzymes.This review focuses on the application of machine learning methods in the engineering of polyethylene terephthalate(PET)hydrolases,enzymes that have the potential to help address plastic pollution.We introduce an overview of machine learning workflows,useful methods and tools for protein design and engineering,and discuss the recent progress of machine learning-aided PET hydrolase engineering and de novo design of PET hydrolases.Finally,as machine learning in enzyme engineering is still evolving,we foresee that advancements in computational power and quality data resources will considerably increase the use of data-driven approaches in enzyme engineering in the coming decades.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA28110300)National Natural Science Foundation of China(No.U23A2004)+3 种基金Natural Science Foundation of Jilin Province,China(No.YDZJ202201ZYTS522)Science and Technology Cooperation Program between Jilin Province and Chinese Academy of Sciences(No.2023SYHZ0053)Innovation Team Program of Northeast Institute of Geography and Agroecology,Chinese Academy of Sciences(No.2023CXTD02)the European Commission under Marie Sk?odowska-Curie(No.101034371)。
文摘Nitrogen(N)enrichment has resulted in widespread alteration of grassland ecosystem processes and functions mainly through disturbance in soil enzyme activities.However,we lack a comprehensive understanding of how N deposition affects specific key soil enzymes that mediate plant-soil feedback of grassland.Here,with a meta-analysis on 1446 cases from field observations in China,we show that N deposition differently affects soil enzymes associated with soil biochemical processes.Specifically,N-promoted C,N,and P-acquiring hydrolase activities significantly increased by 8.73%,7.67%,and 8.69%,respectively,related to an increase in microbial-specific enzyme secretion.The increased relative N availability and soil acidification were two potential mechanisms accounting for the changes in soil enzyme activities with N enrichment.The mixed N addition in combination of NH_(4)NO_(3) and urea showed greater stimulation effect on soil enzyme activities.However,the high rate and long-term N addition tended to weaken the positive responses of soil C-,Nand P-acquiring hydrolase activities to N enrichment.Spatially increased mean annual precipitation and temperature primarily promoted the positive effects of N enrichment on N-and P-acquiring hydrolase activities,and the stimulation of C-and N-acquiring hydrolase activities by N enrichment was intensified with the increase in soil depth.Finally,multimodal inference showed that grassland type was the most important regulator of responses of microbial C,N,and P-acquiring hydrolase activities to N enrichment.This meta-analysis provides a comprehensive insight into understanding the key role of N enrichment in shaping soil enzyme activities of grassland ecosystems.
基金the Department of Biotechnology,Ministry of Science and Technology,India for providing a project(BT/PR25092/NER/95/1009/2017)the Council of Scientific and Industrial Research(CSIR),Govt.of India for providing the CSIR-NET JRF fellowship.
文摘The current study deals with cloning and expressing a maltogenic α-amylase gene from thermophilic Bacillus stercoris YSP18(AmyYSP)in Escherichia coli BL21(DE3).AmyYSP belongs to the GH13_20 subfamily of Glycoside Hydrolases and entails five conserved regions found in maltogenic α-amylases.As a monomer of 67 kDa,AmyYSP exhibits maximal activity at 80℃,pH 5.0 and retains>75%residual activity at 70-100℃ and pH 5.0-8.0.The kinetic and thermodynamic studies displayed that it has a high affinity for soluble starch(K_(m)=1.54±0.236 mgmL^(−1)),exhibits a longer half-life(38.5 h at 80℃ and 8.88 h at 100℃),and a higher EaD value of 3824±1.03 kJ mol^(−1).It was characterised as a Ca^(2+)-independent α-amylase,resistant to various denaturing additives.It hydrolyses soluble starch and raw corn starch efficiently,liberating glucose,maltose,maltotriose and maltotetraose as the main products.The thermostable and acid-stable,maltooligosaccharide forming AmyYSP is a versatile enzyme with prerequisites for successful application in starch-saccharification industries.
基金Supported by Applied Basic Research Project of Suzhou City(SYN201405)National College Students’Innovative Entrepreneurial Training Program(201410285049Z)~~
文摘[Objective] This study aimed to investigate the functions and related mechanisms of xyloglucan Endotransglycosylase/hydrolases （XTHs） during the growth and development of dahlia. [Method] Using /3-actin as the reference gene, the rela- tive transcription levels of DpXTH1 and DpXTH2 genes in roots, stems, leaves and petals of dahlia were analyzed by real-time RT-PCR. [Result] The DpXTH1 and DpXTH2 were not expressed in the roots, but expressed abundantly in the petals of dahlia. There were little expressions in the stems and leaves of dahlia. [Conclusion] The DpXTH1 and DpXTH2 were petal-specific genes and closely related to the growth and development of petals in dahlia.
基金supported by the Project of Sanya Yazhou Bay Science and Technology City,China(SCKJ-JYRC-2022-75)the Natural Science Foundation of Hainan Province,China(322QN398).
文摘Plant pathogens secrete various cell wall-degrading enzymes that compromise host cell wall integrity and facilitate pathogen invasion.This study identified VdGH7a,a glycoside hydrolase family 7(GH7)cellobiohydrolase from Verticillium dahliae,which demonstrated hydrolytic activity against 1,4-β-glucan.Notably,VdGH7a induced cell death in Nicotiana benthamiana when signal peptides were present,though this effect was inhibited by the carbohydrate-binding type-1(CBM1)protein domain.The deletion of VdGH7a substantially reduced V.dahliae pathogenicity in cotton plants,as demonstrated by the mutants’inability to penetrate cellophane membrane.These knockout mutants also exhibited reduced carbon source utilization capacity and increased sensitivity to osmotic and cell wall stresses.Through yeast two-hybrid screening,bi-molecular fluorescence complementation(BiFC),and luciferase complementation imaging(LCI),we identified that VdGH7a interacts with an osmotin-like protein(GhOLP1)in cotton.Virus-induced gene silencing of GhOLP1 resulted in decreased salicylic acid(SA)content and reduced resistance to V.dahliae in cotton,while heterologous overexpression of GhOLP1 in Arabidopsis enhanced both resistance and SA signaling pathway gene expression.These results reveal a virulence mechanism wherein the secreted protein VdGH7a from V.dahliae interacts with GhOLP1 to activate host immunity and contribute significantly to plant resistance against V.dahliae.
基金financially supported by the National Key Research and Development Program of China(No.2020YFA0908000)CAMS Innovation Fund for Medical Sciences(No.CIFMS-2023I2M-2–006)。
文摘Camptothecin,a plant-derived pentacyclic pyrroloquinoline alkaloid,and its derivatives like topotecan and irinotecan have been used as clinical anticancer agents for decades.However,the complete biosynthetic pathway of camptothecin still remains unelucidated due to the unknown complex formation processes and corresponding enzymes for the downstream biosynthetic pathway including the committed hydrolysis of glycosides.Herein,a novel glycoside hydrolase(CaGH1)responsible for the deglycosylation of biosynthetic glycoside intermediates including both quinoline-type alkaloids pumiloside(1),(3S)-deoxypumiloside(2)and indole-type alkaloid strictosamide(3)has been functionally identified.Moreover,CaGH1 exhibits the highly strict stereoselectivity towards the substrates with 3S configuration.Furthermore,a combined strategy for the discovery of the unknown biosynthetic enzyme by employing activity-guided enzyme verification,transcriptome-based gene mining,biochemical assay in vitro,and structurally characterizing the unstable enzymatic products by derivatization,is reported.These findings not only provide a better understanding of the deglycosylation in camptothecin biosynthesis,also lay the foundation for the complete elucidation of camptothecin biosynthetic pathway and biological production of camptothecin.
基金supported by the National Natural Science Foundation of China(No.32171471)Key Research and Development Project of Shandong Province,China(2019JZZY020605)the Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions,Top-notch Academic Programs Project of Jiangsu Higher Education Institutions.
文摘Trehalose is a widely used and safe natural disaccharide.Maltooligosyl trehalose hydrolase(MTHase)is one of the key enzymes for trehalose preparation by double enzyme method using starch or dextrin as substrate.In industrial production,the thermalstability of MTHase is of great significance.We first heterogeneously expressed MTHase from Arthrobacter in E.coli strains BL21(DE3).Based on the overall stability of the protein after virtual saturation mutation predicted by FoldX and the evolutionary information from PSSM,15 mutations were selected and combined.Finally,the combinatorial mutant G589P/A57P was obtained.At 60℃,the t_(1/2)of G589P/A57P and wild type are 37 min and 19 min,respectively,which is 1.9 times higher than that of wild type.The enzyme kinetic parameters of G589P/A57P were analyzed.The K_(M)and k_(cat)are 4.82 mM and 1136 s^(−1),respectively,and the results were close to the wild type,indicating that the mutation did not reduce the catalytic efficiency of the enzyme.The molecular dynamics simulation results show that the rigidity and thermal stability of G589P/A57P protein increase in the range of residues 50-100 and 400-500,which may be due to the proline effect caused by the introduction of proline.
基金supported by the National Natural Science Foundation of China(82274069 and 82003580)Shenzhen science and technology research and development funds(JCYJ20190808171803553 and 2022071718149001)+4 种基金Young Scientific and Technological Talents(Level Two)in Tianjin(QN20230212)Tianjin Education Commission Research Program Project(2024KJ004)Young Elite Scientists Sponsorship Program by China Association of Chinese Medicine(2022-QNRC2-B09)“1+X”Research Project of the Second Hospital of Dalian Medical University(2024JJ11PT005)Eaglet Plan Project of Tianjin University of Traditional Chinese Medicine(XJS2024101)。
文摘Objective:Soluble epoxide hydrolase(sEH)emerges as a target of interest for inflammatory diseases.Piperine is a natural amide alkaloid from Piper nigrum and displays an inhibitory effect toward sEH,its chemical structural transformation was carried out in order to obtain a library of sEH inhibitors based on its skeleton.Methods:Structural transformation of piperine was carried out by chemical methods,and piperine derivatives were assayed for their sEH potentials.A mouse acute lung injury model was constructed by lipopolysaccharide(LPS).Hematoxylin and eosin(H&E)staining,immunofluorescence staining,Western Blot,and enzyme-linked immunosorbent assay were used for investigating the protective potential of sEH inhibitor 11h.Results:Piperine derivatives 11e,11h,11j,and 11o showed inhibitory potentials toward sEH with values of half maximal inhibitory concentration(IC50)from 20 to 70 nM.Compound 11h attenuated the pathological course of LPS-mediated acute lung injury(ALI)in vivo.Furthermore,levels of cytokines tumor necrosis factor alpha(TNF-α),interleukin 6(IL-6),myeloperoxidase(MPO),and lactate dehydrogenase(LDH)were decreased after administration of 11h.The LPS-mediated inflammation and redox unbalance,including expressions of cyclooxygenase-2(COX-2),heme oxygenase-1(HO-1),intercellular cell adhesion molecule-1(ICAM-1),vascular cell adhesion molecule-1(VCAM-1),p-p65/p65,glutamate-cysteine ligase modifier subunit(GCLM),and nuclear factor erythroid-2-related factor 2(Nrf2),were ameliorated through nuclear factor kappa B(NF-κB)and Nrf2 pathways via enhancing levels of epoxyeicosatrienoic acids(EETs)in LPS-exposed ALI mice after compound 11h treatment.Molecular docking demonstrated that the aromatic unsaturated group of 11h occupied a hydrophobic pocket and its urea group formed three hydrogen bonds with Asp333,Tyr381,and Tyr465,which stabilized the active conformation of the ligand.Conclusions:These findings demonstrated that compound 11h may serve as a lead compound for developing sEH inhibitors and treating inflammation related to diseases,such as ALI.
基金supported by research funding provided by Arm&Hammer Animal and Food Production,Waukesha,WI 53186,USA.
文摘Background Body weight is an important indicator of the overall health and production efficiency in broiler chickens.In broiler houses,body weight of chicks is variable despite the same genetics,hatching and feeding practices within a production system.The objective of this study was to investigate the intestinal microbiota and bile salt hydrolase(BSH)activity in slow and fast growing broiler chickens,which belonged to the 10th and 90th percentile body weight groups,respectively.Methods A total of 300 Ross 308 broiler chickens(100 per cohort from three independent cohorts)were selected and mucosal samples from the jejunum,ileum,and cecum were collected at day of arrival,11 and 25(n=450).Then,bacterial counts,16S rRNA amplicon sequencing,species specific real-time qPCR,as well as BSH activity were analyzed.Results Results of bacterial counts showed no significant difference between slow and fast growing cohorts(P>0.05),but they tended to be higher in the slow growing chickens in all measured bacterial groups in cecum.The 16S rRNA amplicon sequencing revealed higher relative abundance of E.coli-Shigella(71.3%−79.8%)at day of arrival,while the most abundant microorganisms at d 25 was Candidatus Arthromitus(slow:44.5%;fast:27.4%)in small intestine.qPCR results indicated significant differences in bacterial populations between the slow and fast growing chickens,especially higher total bacteria,Enterococcus,and Clostridium cluster I in the slow growing chickens at d 25.BSH activity was higher in the slow growing chickens than the fast growing chickens[slow:0.476ΔOD/protein(μg/mL);fast:0.258ΔOD/protein(μg/mL);P<0.0001],and correlation analysis highlighted associations between BSH activity,body weight,feed intake,body weight gain,and bacterial counts.Conclusions We postulate that high total bacteria and Enterococcus abundance are associated with high BSH activity,impacting low feed intake and body weight gain,ultimately resulting in separation into slow and fast growing birds.The findings of this study contribute to understanding the relationship between gut microbiota,BSH activity,and host physiology in broiler chickens,with potential implications for poultry production.
基金the National Key Basic Research Support Foundation of China (No.2005CB121105)theNational Natural Science Foundation of China (No.30670379).
文摘Soil enzymes activities and microbial biomass have an important influence on nutrient cycling. The spatial distribution of soil enzymes activities and microbial biomass were examined along a latitudinal gradient in farmlands of Songliao Plain, Northeast China to assess the impact of climatic changes along the latitudinal transect on nutrient cycling in agroecosystems. Top soils （0-20 cm depth） were sampled in fields at 7 locations from north （Hallun） to south （Dashiqiao） in the end of October 2005 after maize harvest. The contents of total C, N, and P, C/N, available N, and available P increased with the latitude. The activities of invertase and acid phosphatase, microbial biomass （MB） C and N, and MBC/MBN were significantly correlated with latitude （P 〈 0.05, r^2 = 0.198, 0.635, 0.558, 0.211 and 0.317, respectively）, that is, increasing with the latitude. Significant positive correlations （P 〈 0.05） were observed between invertase activity and the total N and available P, and between acid phosphatase activity and the total C, C/N, available N, total P and available P. The urease, acid phosphatase, and dehydrogenase activities were significantly correlated with the soil pH and electrical conductivity （EC） （P 〈 0.05）. MBC and MBN were positively correlated with the total C, C/N, and available P （P 〈 0.05）. The MBC/MBN ratio was positively correlated with the total C, total N, C/N, and available N （P 〈 0.05）. The spatial distribution of soil enzyme activities and microbial biomass resulted from the changes in soil properties such as soil organic matter, soil pH, and EC, partially owing to variations in temperature and rainfall along the latitudinal gradient.
基金the grants from the Korea Research Foundation,No. 2001-003-F00117
文摘AIM:To determine the association of hOGG1 (8-oxoguanine glycosylase I,OGG1) polymorphism of Ser326Cys substitution with colon cancer risk and possible interaction with known environmental risk factors. METHODS:A case-control study with 125 colon cancer cases and 247 controls was conducted, RESULTS:There was no major difference in Ser326Cys genotype distribution between cases and controls.The meat intake tended to increase the odds ratio for colon cancer with an OR of 1.72 (95 % confidence interval;CI=1.12-2.76). Such tendency was more prominent in Cys/Cys carriers (OR=4.31,95 % CI=1.64-11.48),but meat intake was not a significant risk factor for colon cancer in Ser/Ser or Ser/ Cys carriers.The OR for colon cancer was elevated with marginal significance in smokers who were Cys/Cys carriers (OR=2.75,95 % CI=1.07-7.53) but not in Ser/Ser or Ser/ Cys carriers. CONCLUSION:These results suggest that the hOGG1 Ser326Cys polymorphism is probably not a major contributor to individual colon cancer susceptibility overall,but the Cys/ Cys genotype may alter the impact of some environmental factors on colon cancer development.
