Calcium-chelating peptide is a new type of calcium supplement with excellent absorption properties and high bioavailability,safety and stability.This study synthesized calcium chelating peptide from gluten by enzymati...Calcium-chelating peptide is a new type of calcium supplement with excellent absorption properties and high bioavailability,safety and stability.This study synthesized calcium chelating peptide from gluten by enzymatic hydrolysis,determined peptide sequences with high activity,and analyzed their digestive characteristics and stability.The enzymatic hydrolysis process was optimized using response surface methodology to determine the optimal enzymatic hydrolysis conditions of temperature 55?C,p H 8.5,and the ratio of alkaline protease to flavor protease(proportion of enzymes)2.63:1 under a liquid-to-solid ratio of 20:1.The calcium chelation rate of gluten hydrolysate was up to 40.1%under the optimal conditions.Fractional purification was then carried out and results showed that peptides with a molecular weight below 500 Da exhibited the highest chelation rate(51.1%).LC-MS/MS analysis was applied to identify 1224 distinct peptide sequences,among which V.YIPPY?C(WCP1)exhibited a higher calcium chelation rate after screening and molecular docking studies.The synthesized WCP1 displayed a calcium chelation rate as high as 53.5%.Fourier Transform Infrared Spectroscopy(FTIR)confirmed that both carboxyl and phosphate groups play crucial roles in mediating interactions between calcium ions and wheat polypeptides.Circular Dichroism(CD)revealed that the structure of wheat peptide became more compact after chelation.Furthermore,stability experiments indicated that the calcium-chelating peptides displayed notable resistance to digestion as well as excellent p H stability and thermal stability.This study provides technical support for deep processing and functional product development of gluten flour.展开更多
The processes of scallop meats can produce a large amount of by-products like scallop skirts,which are rich in nutrients. This work aimed to obtain the information about antioxidant peptides derived from scallop skirt...The processes of scallop meats can produce a large amount of by-products like scallop skirts,which are rich in nutrients. This work aimed to obtain the information about antioxidant peptides derived from scallop skirts of Mimachlamys nobilis. The hydro-lysates obtained by trypsin exhibited the highest antioxidant activity( 75.6%,79.5% and 76.7% using DPPH,hydroxyl and superoxide anion radical scavenging activity assays,respectively). The antioxidant peptides( MNAP) were separated and purified using UF membranes,GFC processes and RP-HPLC,and the antioxidant activity of MNAP was identified to be 85.7% using DPPH radical scavenging activity assay. The peptides( MNAP) were composed of two peptides with their molecular weights2 855.6 Da and 3 007.2 Da using MALDI-TOF-MS,respectively. The results suggested that the scallop skirts of Mimachlamys nobilis could be explored as a source of antioxidant peptides.展开更多
Four peptides PSPP1,PSPP2,PSPP3 and PSPP4 were purified from the water-extract of Papaver somniferum pollen.Their sequences,with 21,17,13 and 16 amino acid residues respectively,have been determined by Edman degradati...Four peptides PSPP1,PSPP2,PSPP3 and PSPP4 were purified from the water-extract of Papaver somniferum pollen.Their sequences,with 21,17,13 and 16 amino acid residues respectively,have been determined by Edman degradation-N-terminal dansylation.PSPP2, PSPP3 and PSPP4 were synthesized using solid phase method.The immunopromotive activities of PSPP1,PSPP2,PSPP3,PSPP4 and the initially separated sample PSPP have been also observed by the methods of counting erythrocyte rosette forming cells(ERFC) and T-lymphocyte transformation test in vitro.展开更多
[ Objective ] This study aimed to extract antibacterial peptides from mussel. [ Method ] Blue mussels were used as raw materials for direct extraction of antibacterial peptides by using O. 5 % acetic acid, and the ant...[ Objective ] This study aimed to extract antibacterial peptides from mussel. [ Method ] Blue mussels were used as raw materials for direct extraction of antibacterial peptides by using O. 5 % acetic acid, and the antibacterial peptides were isolated and purified by Sephacryl S-100 polyacrylamide gel chromatography. The fractions were collected for measurement of antibacterial activity and minimum inhibitory concentration for a variety of bacterial species by filter paper diffusion assay. Molecular weight of the antibacterial peptides was determined by SDS-PAGE. Variation of antibacterial activity of antibacterial peptides was measured at 100 ~C under conditions of different processing time and different pH. [ Result] The O. 5% acetic acid was used for crude extraction of antibacterial peptides as extrac- tion solution and led to relatively high extraction efficiency. By using Sephacryl S-100, the antibacterial peptides could be purified as a single substance. The isola- ted and purified antibacterial peptides of mussel had relatively strong antibacterial properties with molecular weight of 5 908, showing heat-resistance acid-alkaline resistance. [ Conclusion] This study laid the theoretical foundation for large-scale production of antibacterial peotides.展开更多
Antioxidant peptides of flatfish skin protein hydrolyzed by four enzymes （Papain, Pepsin, Trypsin and Neutrase, respectively）were investigated. The Trypsin hydrotysate obtained by hydrolysis exhibited the highest 1,...Antioxidant peptides of flatfish skin protein hydrolyzed by four enzymes （Papain, Pepsin, Trypsin and Neutrase, respectively）were investigated. The Trypsin hydrotysate obtained by hydrolysis exhibited the highest 1,1- dipheny-l-2-picrylhydrazyl（DPPH） radical scavenging activity （DRSA） compared with other hydrolysates. Re- sponse surface method ology （RSM）, based on Box-Behnken design, was used to study the influence of hydrolysis conditions on the DRSA. The optimal hydrolysis conditions were as follows： pH 7.38, temperature 48.2~C and en- zyme/substrate （E/S）ratio 2 840 U/g. Under these conditions, the maximum DRSA was （22.85 ＋ 0.57）%. The experimental values agreed with the value （23.09%） predicted by the model within a 95% confidence interval. By using gel filtration chromatography and reversed-phase high performance liquid chromatography （RP-HPLC）, anti- oxidant peptide （D2-P）was isolated from flatfish skin protein hydrolysates （FSPH）and could exhibit a （54.28 ± 1.37） % scavenging activity on DPPH radical at the concentration of 5 mg/mL. This is the first report of a scientific basis for the preparation of antioxidant peptides from flatfish skin. The results suggested that the antioxidant pep- tides can be exploited into functional foods or used as a novel source of nutraceuticals.展开更多
Anti-hepatic fibrosis peptide from Carapax Trionycis was purified, characterized, and inhibitory effect was assessed. Carapax Trionycis extract peptide hydrolysates （CTEPHs） were separated by ultrafiltration, Sephad...Anti-hepatic fibrosis peptide from Carapax Trionycis was purified, characterized, and inhibitory effect was assessed. Carapax Trionycis extract peptide hydrolysates （CTEPHs） were separated by ultrafiltration, Sephadex G-15 gel chromatography and RP-HPLC. One novel anti-hepatic fibrosis peptide （CTEPH-I： Asn-Pro-Asn-Pro-Thr） was obtained and identified. MTS assay and enzyme-linked immunosorbent assay were applied to evaluate the anti-fibrotic effect of CTEPH-1 on activated hepatic stellate cells （HSCs） in vitro. CTEPH-1 efficiently inhibited activation and proliferation of cultured HSC-T6 cells via lowering the contents of collagen and TIMP- 1 except for matrix metalloproteinase- 1 （MMP- 1）. The purified peptide might be beneficial as functional food or potential drug for treatment of liver fibrogenesis.展开更多
AIM:To purify the heat shock protein (HSP) 70-associated tumor peptides and to observe its non-MHC-I molecule restrictive antitumor effect.METHODS:By ConA-sepharose affinity chromatography,ADP-agarose affinity chromat...AIM:To purify the heat shock protein (HSP) 70-associated tumor peptides and to observe its non-MHC-I molecule restrictive antitumor effect.METHODS:By ConA-sepharose affinity chromatography,ADP-agarose affinity chromatography, and DEAE anion exchange chromatography, we were able to purify HSP70-associated peptides from mouse hepatoma (HCaF) cells treated in heat shock at 42℃. Specific active immunization and adoptive cellular immunization assay were adopted to observe the immunoprotective effect elicited by HSP70-associated peptide complexes isolated from HcaF.RESULTS: The finally purified HSP-associated peptides had a very high purity and specificity found by SDS-PAGE and Western blot. Mice immunized with HSP70-associated peptide complexes purified from HCaF cells were protected from HCaF living cell challenge. This effect was dose dependent.Adoptive immunization of immune spleen cells of mice immunized with HSP70-associated peptide complexes could elicit immunity against HCaF challenge, and the tumor-free mice could resist repeated challenges. This effect could be continuously enhanced by repeated challenge with HCaF living cells. The tumor-free mice could tolerate the challenge for as high as 1×10^7 HCaF cells. The mice immunized once with spleen cells pulsed with HSP70-associated peptide complexes in vitro could also result in a certain adoptive immunity against HCaF.CONCLUSION:High purity and specificity of HSP70-associated peptides could be achieved from tumor cells by the low-pressure affinity chromatography method used in this study. HSP70-associated peptide complexes derived from the HCaF can elicit non-MHC-I molecule restrictive immunoprotective effect against HCaF.This effect can be transferred by adoptive immunization to mice and enhanced by repeated challenge with HCaF live cells.展开更多
Mackerel （Pneumatophorus japonicus） proteins were hydrolyzed by five proteases： trypsin, papain, neutrase, acid protease, and flavourzyme. The hydrolysate treated by neutrase exhibited the highest antioxidant activ...Mackerel （Pneumatophorus japonicus） proteins were hydrolyzed by five proteases： trypsin, papain, neutrase, acid protease, and flavourzyme. The hydrolysate treated by neutrase exhibited the highest antioxidant activity. Response surface methodology （RSM） was employed to optimize the hydrolysis conditions in an effort to obtain a mackerel protein hydrolysate （MPH） with the highest DPPH radical scavenging activity. The MPH was fractioned using a series of ultrafiltration membranes and five fractions, namely, MPH-I （〉10 kDa）, MPH-II （10-2.5 kDa）, MPH-III （1-2.5 kDa）, MPH-IV （0.4-1 kDa）, and MPH-V （below 0.4 kDa）, were obtained. DPPH radical scavenging activity, reducing power, hydroxyl radical scavenging activity, and the lipid peroxidation inhibition capability of these fractions were evaluated. The fractions in molecular weights 〈2.5 kDa （MPH-III, MPH-IV, and MPH-V）, which occupied 93.4% of the total fractions, showed the strongest antioxidant activity; and the antioxidant activities of the three fractions are similar to each other. Using SP Sephadex C-25 and Sephadex G-25 columns, eight fractions were obtained from the MPH （〈2.5 kDa）. The isolated peptide I （1 664 kDa） displayed the highest DPPH radical scavenging activity. Therefore, MPH is a potential source of antioxidant peptides.展开更多
Three angiotensin I converting enzyme(ACE) inhibition peptides were isolated from sandworm Sipunculus nudus protein hydrolysate prepared using protamex. Consecutive purification methods, including size exclusion chrom...Three angiotensin I converting enzyme(ACE) inhibition peptides were isolated from sandworm Sipunculus nudus protein hydrolysate prepared using protamex. Consecutive purification methods, including size exclusion chromatography and reverse-phase high performance liquid chromatography(RP-HPLC), were used to isolate the ACE inhibition peptides. The amino acid sequences of the peptides were identified as Ile-Asn-Asp, Val-Glu-Pro-Gly and Leu-Ala-Asp-Glu-Phe. The IC_(50) values of the purified peptides for ACE inhibition activity were 34.72 μmol L^(-1), 20.55 μmol L^(-1) and 22.77 μmol L^(-1), respectively. These results suggested that S. nudus proteins contain specific peptides that can be released by enzymatic hydrolysis. This study may provide an experimental basis for further systematic research, rational development and clinical utilization of sandworm resources.展开更多
Objective To try making huZP3a^22-176 and huZP3b^177-348 polypeptides （representing an intact huZP^322-348 protein without its N-terminal signal peptide and C-terminal transmembrane domain ） express in E. coli at a ...Objective To try making huZP3a^22-176 and huZP3b^177-348 polypeptides （representing an intact huZP^322-348 protein without its N-terminal signal peptide and C-terminal transmembrane domain ） express in E. coli at a higher level Methods The cDNAs encoding huZP3a and huZP3b were obtained with PCR method. The pBV221 plasmid was used to construct thermo-inducible recombinant expression vector. Purification of two target expression products employed an improved method of preparative gel polyacrylamide gel electrophoresis. Results Two polypeptides of recombinant huZP3a （rhuZP3a） and recombinant huZP3b （rhuZP3b） were all expressed respectively in an E. coli BL21（DE3）pLysS strain at a higher level, which were recognized by two specific polyclonal antisera in Western blotting test which recognize a linear B cell epitope present in rhuZP3a or rhuZP3b respectively. Using the shake-flask method, approximately 5 mg of rhuZP3a and rhuZP3b with more than 95% relative homogeneity were harvested from 1 L culture respectively. Conclusion The availability of two rhuZP3 polypeptides will help in detecting the immunogenicities of rhuZP3a and rhuZP3b through animal experiments and confirming the function domain of non-glycosylated huZP3 to induce acrosome reaction in vitro.展开更多
Four peptide components RP1,RP2,RP3Ⅰ and RP3Ⅱ were purified from the water—ex- tract of rape(Brassica campestris L.)pollen.The primary sequence of RP3I,with 12 amino acid residues,has been determined by Edman degra...Four peptide components RP1,RP2,RP3Ⅰ and RP3Ⅱ were purified from the water—ex- tract of rape(Brassica campestris L.)pollen.The primary sequence of RP3I,with 12 amino acid residues,has been determined by Edman degradation—N—terminal dansylation.The immunopro- motive activities of the initially separated sample and RP3I have been also observed in vitro.展开更多
Globally, peptide-based anticancer therapies have drawn much attention. Marine organisms are a reservoir of anticancer peptides that await discovery. In this study, we aimed to identify cytotoxic oligopeptides from Sa...Globally, peptide-based anticancer therapies have drawn much attention. Marine organisms are a reservoir of anticancer peptides that await discovery. In this study, we aimed to identify cytotoxic oligopeptides from Sarcophyton glaucum. Peptides were purified from among the S. glaucum hydrolysates produced by alcalase, chymotrypsin, papain, and trypsin, guided by a methylthiazolyldiphenyl-tetrazolium bromide(MTT) assay on the human cervical cancer(HeLa) cell line for cytotoxicity evaluation. Purification techniques adopted were membrane ultrafiltration, gel filtration chromatography, solid phase extraction(SPE), and reversed-phase high-performance liquid chromatography(RP-HPLC). Purified peptides were identified by de novo peptide sequencing. From papain hydrolysate, three peptide sequences were identified: AGAPGG, AERQ, and RDTQ(428.45, 502.53, and 518.53 Da, respectively). Peptides synthesized from these sequences exhibited cytotoxicity on HeLa cells with median effect concentration(EC50) values of 8.6, 4.9, and 5.6 mmol/L, respectively, up to 5.8-fold stronger than the anticancer drug 5-fluorouracil. When tested at their respective EC50, AGAPGG, AERQ, and RDTQ showed only 16%, 25%, and 11% cytotoxicity to non-cancerous Hek293 cells, respectively. In conclusion, AERQ, AGAPGG, and RDTQ are promising candidates for future development as peptide-based anticancer drugs.展开更多
Developing on-demand biomass valorization represents an ideal path to alleviate the double burden of a sustainable energy-environment future,yet exploring tunable lignin-first chemistry to accomplish multifunctional w...Developing on-demand biomass valorization represents an ideal path to alleviate the double burden of a sustainable energy-environment future,yet exploring tunable lignin-first chemistry to accomplish multifunctional water purification remains elusive.Herein,we report a versatile solvent-fractionation to construct heteroatom-doped multicolor lignin carbon quantum dots(CQDs)with the functions of bimodal pollutant sensing,metal-ionic visualization,and photocatalytic antibiotic dissociation.With the aid of oxidation cleavage and biphasic extraction,the underlying lignin features of molecular weight and functional linkages influence the quantum size and core-surface state of CQDs conferring the unique optical-structure-performance.The N,S co-doped blue-emitting CQDs via light-quenching offer the selective identification of Fe^(3+)-ions in a broad response range with an acceptable limit of detection.The addition of L-cysteine can efficiently restore the fluorescence of CQDs by forming a stable Fe^(3+)-L-cys complex.The green-emissive CQDs are facilely embedded into cellulose hydrogel to directly visualize the presence of metal-ions.A red-CQDs modified ternary ZnIn2S4(ZIS)composite is fabricated to achieve photocatalytic antibiotic removal with an efficiency of~85%.The excellent photo-generated electron and storage capabilities of CQDs improve the light-capturing,electron conduction,and charge carrier separation of ZIS.The reactive species are of importance to photocatalytic tetracycline oxidation,wherein the electron holes(h+)function as the main contributor followed by∙O_(2)^(-),1O2 and∙OH.The directly interfacial electron escaping-shuttling with the help of optimized electronic and energy-band structures is confirmed via electrochemical test and theoretical computation.We anticipate that the present work not only sheds substantial light to manipulate polychromatic lignin-based CQDs via a tailored solvent-engineering,but also presents an emerging green route of emphasizing biomass-water nexus.展开更多
Fluorescent probes,with their superior optical properties and labeling versatility,have greatly advanced the visualization of intracellular molecules and subcellular structures.However,poor cytoplasmic delivery,caused...Fluorescent probes,with their superior optical properties and labeling versatility,have greatly advanced the visualization of intracellular molecules and subcellular structures.However,poor cytoplasmic delivery,caused by charge,size,or targeting groups,limits the effective use of many fluorescent probes in live cells.Recently,cell-penetrating peptides(CPPs)have emerged as efficient carriers,offering great potential for the cytoplasmic delivery of fluorescent probes in live cells.This review provides a comprehensive overview of CPPs as vehicles for probe delivery,outlining advances in their development,conjugation chemistries,and intracellular delivery mechanisms.Recent applications in live-cell imaging are highlighted and organized according to major CPP modification strategies,including sequence engineering,cyclization,hybrid design and enhancement by chemical reagents.Finally,the challenges that remain and the future outlook of this rapidly evolvingfield are discussed.展开更多
High-quality steel production requires superior-performance refractories.To meet the requirements of quality enhancement and efficiency improvement in the steelmaking industry,the application of the novel microporous ...High-quality steel production requires superior-performance refractories.To meet the requirements of quality enhancement and efficiency improvement in the steelmaking industry,the application of the novel microporous magnesia with high strength,remarkable slag resistance,and excellent thermal insulation is promoted.The interface reaction between H13 steel and novel microporous magnesia castable was investigated by using the crucible method,to elucidate the molten steel purification mechanism.The interface microstructure was observed by scanning electron microscopy,and the composition,size,and amount of inclusions were statistically analyzed.A thermal calculation was conducted to gain a deeper understanding of the modification process of inclusions.Fused magnesia castables were used as the blank control.The results show that the average number density and size of inclusions were reduced by 5.99 mm^(−2) and 0.28μm respectively after the same reaction time because the micropores enhanced the inclusion adsorption.The size of inclusions caused by erosion decreased.Also,more[Mg]dissolved into molten steel over 60 min reaction time and resulted in a 0.49 wt.%increase in inclusion Mg content,which modified the inclusion by decreasing their melting point.Therefore,applying novel microporous magnesia was beneficial for purifying H13 steel.展开更多
Peptides play important roles in chemistry,medicinal chemistry and life science,due to their high efficiency and specificity,unusual biological and therapeutic properties.As naturally occurring peptides often face wit...Peptides play important roles in chemistry,medicinal chemistry and life science,due to their high efficiency and specificity,unusual biological and therapeutic properties.As naturally occurring peptides often face with their intrinsic limitations including metabolic instability and low membrane permeability,the strategies for synthesizing unnatural amino acids and peptides are explored.Among the methods for modifying amino acids and peptides,chemo-and site-selective approaches are preferred because of the ability to fine-tuning structural features.Recently,transition metal-catalyzed C–H activation has been employed for the functionalization of amino acids and peptides.Through domino C–H activation/annulation,a series of structurally complex and diverse amino acids and peptides is constructed.This review highlights recent advances in the synthesis of unnatural amino acids and peptides via transition metal-catalyzed C–H activation/annulation.展开更多
The escalating global crisis of antibiotic resistance necessitates urgent development of novel antimicrobial agents.In this context,antimicrobial peptides(AMPs)derived from fish emerge as a highly promising strategic ...The escalating global crisis of antibiotic resistance necessitates urgent development of novel antimicrobial agents.In this context,antimicrobial peptides(AMPs)derived from fish emerge as a highly promising strategic resource,owing to their unique structural diversity and the exceptional adaptability and tolerance conferred by evolutionary pressures in aquatic environments.This review systematically synthesizes key advances in fish-derived AMP research.It details their diverse sourcing avenues,encompassing tissues from live fish(e.g.,skin,mucus,gills,intestines)and processing byproducts(e.g.,scales,skins,viscera).The discussion covers efficient isolation,purification,and synthesis strategies,and critically examines their defining feature:unique multi-target synergistic antimicrobial mechanisms(including microbial membrane disruption,intracellular targeting,and immunomodulation),which contribute to a reduced propensity for resistance development.To address inherent limitations of natural AMPs(such as susceptibility to proteolysis and potential toxicity),the review highlights innovative optimization approaches,including computational-aided rational design,amino acid modification,cyclization,and hybrid peptide construction.Furthermore,the review elaborates on their significant application potential across crucial domains:food preservation(inhibiting spoilage organisms,extending shelf-life),sustainable aquaculture(as antibiotic alternatives,enhancing disease resistance,improving water quality),and the development of novel anti-infective therapeutics(particularly against drug-resistant infections).Therefore,this work aims to provide a comprehensive theoretical foundation and innovative strategic insights to foster in-depth research and the sustainable exploitation of this vital strategic biological resource.展开更多
Insects represent emerging sources of bioactive peptides and functional materials.Mantidis Oötheca(Sang-Piao-Xiao in Chinese,SPX)serves as an insect-derived medicine for treating kidney disease.This study demonst...Insects represent emerging sources of bioactive peptides and functional materials.Mantidis Oötheca(Sang-Piao-Xiao in Chinese,SPX)serves as an insect-derived medicine for treating kidney disease.This study demonstrated that supernatant(SPX)improved kidney function in adriamycin(ADR)-induced nephropathy mice model.Transcriptomic analysis revealed that SPX inhibited complement activation by targeting the MASP1-C3/C3a receptor(C3aR)pathway.Peptidomic analysis identified 304 peptides from SPX,with 49 peptides selected for evaluation using prediction tools and molecular docking with complement core protein C3.Three peptides(PMGFPFDR,FNDPK,AAQFFNR)exhibiting docking scores below-8.0 were synthesized to verify complement inhibition and anti-fibrotic activities.The synthetic peptide AAQFFNR demonstrated complement inhibitory activity,with an inhibitory complement hemolytic 50%(ICH_(50))value of 24.54μmol·L^(-1),and exhibited superior protective effects in ADR-induced HK-2 cells.Surface plasmon resonance(SPR)assay revealed direct interaction between AAQFFNR and complement C3 with K_(d)value of 16.8μmol·L^(-1).The reno-protective effect of AAQFFNR was subsequently verified in ADR-induced mice.This research provides initial evidence that complement C3-inhibiting peptides from insects demonstrate potential in preventing nephropathy through in silico and in vivo validation approaches.展开更多
The naturally fermented Inner Mongolian cheese’s flavor and nutritional value make it a popular choice among customers.In this work,to create multi-functional peptides that have taste and biological activity,peptidom...The naturally fermented Inner Mongolian cheese’s flavor and nutritional value make it a popular choice among customers.In this work,to create multi-functional peptides that have taste and biological activity,peptidomics and bioinformatics were used to screen flavor peptides from Inner Mongolian cheese and further assess their antioxidant and angiotensin I-converting enzyme(ACE)inhibitory properties.According to sensory data,YH8 and IL7 had detectable bitter tastes with low thresholds of 0.03 and 0.06 mmol/L,respectively.With an umami threshold range of 0.24‒0.81 mmol/L,VQ6,FK13,HP13 and QT14 exhibited a range of flavors dominated by umami,including sweet,bitter,salty,sour and kokumi.Antioxidant activity wise,YH8,VQ6,HP13 and QT14 were well represented.The above-mentioned peptides all had some ACE inhibitory effect.The bitter peptide IL7(IC_(50)=0.08 mmol/L)had the highest level of ACE inhibitory activity,followed by YH8(IC_(50)=0.33 mmol/L).These multi-functional peptides,which have been assessed for bioactive and taste features in Inner Mongolian cheese,may have positive impacts on health and harmonize the cheese’s overall flavor.These results suggest that some flavor peptides produced in fermented foods might be with bioactivities while providing a basis for the exploration and application of multi-functional peptides.展开更多
The equilibrium between the supply and demand of water purification services is essential for safeguarding watershed ecosystems and supporting sustainable socio-economic growth.While current research mainly emphasizes...The equilibrium between the supply and demand of water purification services is essential for safeguarding watershed ecosystems and supporting sustainable socio-economic growth.While current research mainly emphasizes the static analysis of this balance,dynamic investigations into service flow characteristics remain scarce.This study focuses on the Xiangjiang River Basin in southern China,utilizing the InVEST model,differential equations governing supply and demand,and social network analysis to investigate the spatio-temporal patterns of water purification service supply and demand.The results reveal that between 2000 and 2020,the supply of water purification services showed a slight upward trend,while demand exhibited a fluctuating downward tendency,and the supply-demand surplus fluctuated.On an annual basis,the supply generally met the demand,but significant spatial variation in supply-demand balance was observed,with high-risk zones concentrated in the central Hengshao arid corridor and the northern Changzhutan metropolitan area.In the water purification service network,surplus nodes increased,while deficit nodes decreased over time.Network density improved from 98.96%in 2000 to 100%in 2020.The flow of surplus services from upstream regions alleviated supply-demand imbalances downstream,notably in the Hengyang-Shaoyang(Hengshao)arid corridor and the Changsha-Zhuzhou-Xiangtan(Changzhutan)metropolitan area.However,during drought years,diminished water volume intensified supply-demand pressures in these regions.This research framework,which incorporates the dynamic effects of service flow,broadens the scope of water purification service studies and provides a solid foundation for integrated water resource and environmental management.展开更多
基金Innovation Ability Improvement Project of Science and Technology Small and Medium-sized Enterprises in Shandong Province:2023TSGC0892,2022TSGC2520Project supported by Qingdao Natural Science Foundation:23-2-1-180-zyyd-jch+3 种基金Key R&D Program of Shandong Province,China:2023TZXD078Shandong Province Technology Innovation Guidance Plan:YDZX2023035Qingdao People’s Livelihood Science and Technology Plan Project:23-2-8-xdny-6-nsh,23-3-8-xdny-1-nshThe Two Hundred Talents Project of Yantai City in 2020。
文摘Calcium-chelating peptide is a new type of calcium supplement with excellent absorption properties and high bioavailability,safety and stability.This study synthesized calcium chelating peptide from gluten by enzymatic hydrolysis,determined peptide sequences with high activity,and analyzed their digestive characteristics and stability.The enzymatic hydrolysis process was optimized using response surface methodology to determine the optimal enzymatic hydrolysis conditions of temperature 55?C,p H 8.5,and the ratio of alkaline protease to flavor protease(proportion of enzymes)2.63:1 under a liquid-to-solid ratio of 20:1.The calcium chelation rate of gluten hydrolysate was up to 40.1%under the optimal conditions.Fractional purification was then carried out and results showed that peptides with a molecular weight below 500 Da exhibited the highest chelation rate(51.1%).LC-MS/MS analysis was applied to identify 1224 distinct peptide sequences,among which V.YIPPY?C(WCP1)exhibited a higher calcium chelation rate after screening and molecular docking studies.The synthesized WCP1 displayed a calcium chelation rate as high as 53.5%.Fourier Transform Infrared Spectroscopy(FTIR)confirmed that both carboxyl and phosphate groups play crucial roles in mediating interactions between calcium ions and wheat polypeptides.Circular Dichroism(CD)revealed that the structure of wheat peptide became more compact after chelation.Furthermore,stability experiments indicated that the calcium-chelating peptides displayed notable resistance to digestion as well as excellent p H stability and thermal stability.This study provides technical support for deep processing and functional product development of gluten flour.
基金Sponsored by the National Science&Technology Pillar Program During the 12th Five-year Plan Period(Grant No.2015BAD17B03)Subject Construction Fund Guided by HIT(Grant No.WH20150206,WH20160206)Key Research and Development Plan of Shandong Province(Grant No.2015GSF115016)
文摘The processes of scallop meats can produce a large amount of by-products like scallop skirts,which are rich in nutrients. This work aimed to obtain the information about antioxidant peptides derived from scallop skirts of Mimachlamys nobilis. The hydro-lysates obtained by trypsin exhibited the highest antioxidant activity( 75.6%,79.5% and 76.7% using DPPH,hydroxyl and superoxide anion radical scavenging activity assays,respectively). The antioxidant peptides( MNAP) were separated and purified using UF membranes,GFC processes and RP-HPLC,and the antioxidant activity of MNAP was identified to be 85.7% using DPPH radical scavenging activity assay. The peptides( MNAP) were composed of two peptides with their molecular weights2 855.6 Da and 3 007.2 Da using MALDI-TOF-MS,respectively. The results suggested that the scallop skirts of Mimachlamys nobilis could be explored as a source of antioxidant peptides.
文摘Four peptides PSPP1,PSPP2,PSPP3 and PSPP4 were purified from the water-extract of Papaver somniferum pollen.Their sequences,with 21,17,13 and 16 amino acid residues respectively,have been determined by Edman degradation-N-terminal dansylation.PSPP2, PSPP3 and PSPP4 were synthesized using solid phase method.The immunopromotive activities of PSPP1,PSPP2,PSPP3,PSPP4 and the initially separated sample PSPP have been also observed by the methods of counting erythrocyte rosette forming cells(ERFC) and T-lymphocyte transformation test in vitro.
基金Supported by Natural Science Foundation of Shandong Province ( ZR2009BM0190A)
文摘[ Objective ] This study aimed to extract antibacterial peptides from mussel. [ Method ] Blue mussels were used as raw materials for direct extraction of antibacterial peptides by using O. 5 % acetic acid, and the antibacterial peptides were isolated and purified by Sephacryl S-100 polyacrylamide gel chromatography. The fractions were collected for measurement of antibacterial activity and minimum inhibitory concentration for a variety of bacterial species by filter paper diffusion assay. Molecular weight of the antibacterial peptides was determined by SDS-PAGE. Variation of antibacterial activity of antibacterial peptides was measured at 100 ~C under conditions of different processing time and different pH. [ Result] The O. 5% acetic acid was used for crude extraction of antibacterial peptides as extrac- tion solution and led to relatively high extraction efficiency. By using Sephacryl S-100, the antibacterial peptides could be purified as a single substance. The isola- ted and purified antibacterial peptides of mussel had relatively strong antibacterial properties with molecular weight of 5 908, showing heat-resistance acid-alkaline resistance. [ Conclusion] This study laid the theoretical foundation for large-scale production of antibacterial peotides.
基金Supported by the Key Technology R&D Program of Tianjin(No.14ZCZDNC00008)
文摘Antioxidant peptides of flatfish skin protein hydrolyzed by four enzymes （Papain, Pepsin, Trypsin and Neutrase, respectively）were investigated. The Trypsin hydrotysate obtained by hydrolysis exhibited the highest 1,1- dipheny-l-2-picrylhydrazyl（DPPH） radical scavenging activity （DRSA） compared with other hydrolysates. Re- sponse surface method ology （RSM）, based on Box-Behnken design, was used to study the influence of hydrolysis conditions on the DRSA. The optimal hydrolysis conditions were as follows： pH 7.38, temperature 48.2~C and en- zyme/substrate （E/S）ratio 2 840 U/g. Under these conditions, the maximum DRSA was （22.85 ＋ 0.57）%. The experimental values agreed with the value （23.09%） predicted by the model within a 95% confidence interval. By using gel filtration chromatography and reversed-phase high performance liquid chromatography （RP-HPLC）, anti- oxidant peptide （D2-P）was isolated from flatfish skin protein hydrolysates （FSPH）and could exhibit a （54.28 ± 1.37） % scavenging activity on DPPH radical at the concentration of 5 mg/mL. This is the first report of a scientific basis for the preparation of antioxidant peptides from flatfish skin. The results suggested that the antioxidant pep- tides can be exploited into functional foods or used as a novel source of nutraceuticals.
基金The Foundation of the Education Department of Hubei Province(Grant No.D20162004)
文摘Anti-hepatic fibrosis peptide from Carapax Trionycis was purified, characterized, and inhibitory effect was assessed. Carapax Trionycis extract peptide hydrolysates （CTEPHs） were separated by ultrafiltration, Sephadex G-15 gel chromatography and RP-HPLC. One novel anti-hepatic fibrosis peptide （CTEPH-I： Asn-Pro-Asn-Pro-Thr） was obtained and identified. MTS assay and enzyme-linked immunosorbent assay were applied to evaluate the anti-fibrotic effect of CTEPH-1 on activated hepatic stellate cells （HSCs） in vitro. CTEPH-1 efficiently inhibited activation and proliferation of cultured HSC-T6 cells via lowering the contents of collagen and TIMP- 1 except for matrix metalloproteinase- 1 （MMP- 1）. The purified peptide might be beneficial as functional food or potential drug for treatment of liver fibrogenesis.
基金Supported by the National Natural Science Foundation of China,No.3973440-Ⅱ
文摘AIM:To purify the heat shock protein (HSP) 70-associated tumor peptides and to observe its non-MHC-I molecule restrictive antitumor effect.METHODS:By ConA-sepharose affinity chromatography,ADP-agarose affinity chromatography, and DEAE anion exchange chromatography, we were able to purify HSP70-associated peptides from mouse hepatoma (HCaF) cells treated in heat shock at 42℃. Specific active immunization and adoptive cellular immunization assay were adopted to observe the immunoprotective effect elicited by HSP70-associated peptide complexes isolated from HcaF.RESULTS: The finally purified HSP-associated peptides had a very high purity and specificity found by SDS-PAGE and Western blot. Mice immunized with HSP70-associated peptide complexes purified from HCaF cells were protected from HCaF living cell challenge. This effect was dose dependent.Adoptive immunization of immune spleen cells of mice immunized with HSP70-associated peptide complexes could elicit immunity against HCaF challenge, and the tumor-free mice could resist repeated challenges. This effect could be continuously enhanced by repeated challenge with HCaF living cells. The tumor-free mice could tolerate the challenge for as high as 1×10^7 HCaF cells. The mice immunized once with spleen cells pulsed with HSP70-associated peptide complexes in vitro could also result in a certain adoptive immunity against HCaF.CONCLUSION:High purity and specificity of HSP70-associated peptides could be achieved from tumor cells by the low-pressure affinity chromatography method used in this study. HSP70-associated peptide complexes derived from the HCaF can elicit non-MHC-I molecule restrictive immunoprotective effect against HCaF.This effect can be transferred by adoptive immunization to mice and enhanced by repeated challenge with HCaF live cells.
基金Supported by the Commonweal Item of State Oceanic Administration of the People's Republic of China(Nos.201305016-2,201405038-2)
文摘Mackerel （Pneumatophorus japonicus） proteins were hydrolyzed by five proteases： trypsin, papain, neutrase, acid protease, and flavourzyme. The hydrolysate treated by neutrase exhibited the highest antioxidant activity. Response surface methodology （RSM） was employed to optimize the hydrolysis conditions in an effort to obtain a mackerel protein hydrolysate （MPH） with the highest DPPH radical scavenging activity. The MPH was fractioned using a series of ultrafiltration membranes and five fractions, namely, MPH-I （〉10 kDa）, MPH-II （10-2.5 kDa）, MPH-III （1-2.5 kDa）, MPH-IV （0.4-1 kDa）, and MPH-V （below 0.4 kDa）, were obtained. DPPH radical scavenging activity, reducing power, hydroxyl radical scavenging activity, and the lipid peroxidation inhibition capability of these fractions were evaluated. The fractions in molecular weights 〈2.5 kDa （MPH-III, MPH-IV, and MPH-V）, which occupied 93.4% of the total fractions, showed the strongest antioxidant activity; and the antioxidant activities of the three fractions are similar to each other. Using SP Sephadex C-25 and Sephadex G-25 columns, eight fractions were obtained from the MPH （〈2.5 kDa）. The isolated peptide I （1 664 kDa） displayed the highest DPPH radical scavenging activity. Therefore, MPH is a potential source of antioxidant peptides.
基金supported by research grant of Guangxi Key Laboratory Traditional Chinese Medicine Quality Standards (No. GXGZZK201501)the Open Research Fund Program of Guangxi Key Laboratory of Marine Biotechnology (No. GLMBT-201407)+1 种基金partly supported by Shanghai Fengxian District Science and Technology Project (Nos. 20141001 and 20151205)Shanghai No. 6 People’s Medical Group Project and research project of Shanghai municipal health and Family Planning Commission (No. 201540027)
文摘Three angiotensin I converting enzyme(ACE) inhibition peptides were isolated from sandworm Sipunculus nudus protein hydrolysate prepared using protamex. Consecutive purification methods, including size exclusion chromatography and reverse-phase high performance liquid chromatography(RP-HPLC), were used to isolate the ACE inhibition peptides. The amino acid sequences of the peptides were identified as Ile-Asn-Asp, Val-Glu-Pro-Gly and Leu-Ala-Asp-Glu-Phe. The IC_(50) values of the purified peptides for ACE inhibition activity were 34.72 μmol L^(-1), 20.55 μmol L^(-1) and 22.77 μmol L^(-1), respectively. These results suggested that S. nudus proteins contain specific peptides that can be released by enzymatic hydrolysis. This study may provide an experimental basis for further systematic research, rational development and clinical utilization of sandworm resources.
基金This work was supported by grant (No. 03JG05014) from the Population Family Planning Commission ofShanghai. China and the Medical and Health Science Research Foundation of Zhejiang Province(No. 2004A002)
文摘Objective To try making huZP3a^22-176 and huZP3b^177-348 polypeptides （representing an intact huZP^322-348 protein without its N-terminal signal peptide and C-terminal transmembrane domain ） express in E. coli at a higher level Methods The cDNAs encoding huZP3a and huZP3b were obtained with PCR method. The pBV221 plasmid was used to construct thermo-inducible recombinant expression vector. Purification of two target expression products employed an improved method of preparative gel polyacrylamide gel electrophoresis. Results Two polypeptides of recombinant huZP3a （rhuZP3a） and recombinant huZP3b （rhuZP3b） were all expressed respectively in an E. coli BL21（DE3）pLysS strain at a higher level, which were recognized by two specific polyclonal antisera in Western blotting test which recognize a linear B cell epitope present in rhuZP3a or rhuZP3b respectively. Using the shake-flask method, approximately 5 mg of rhuZP3a and rhuZP3b with more than 95% relative homogeneity were harvested from 1 L culture respectively. Conclusion The availability of two rhuZP3 polypeptides will help in detecting the immunogenicities of rhuZP3a and rhuZP3b through animal experiments and confirming the function domain of non-glycosylated huZP3 to induce acrosome reaction in vitro.
文摘Four peptide components RP1,RP2,RP3Ⅰ and RP3Ⅱ were purified from the water—ex- tract of rape(Brassica campestris L.)pollen.The primary sequence of RP3I,with 12 amino acid residues,has been determined by Edman degradation—N—terminal dansylation.The immunopro- motive activities of the initially separated sample and RP3I have been also observed in vitro.
基金Project supported by the Fundamental Research Grant Scheme of the Ministry of Higher Education,Malaysia(FRGS/1/2013/ST04/UTAR/02/1)
文摘Globally, peptide-based anticancer therapies have drawn much attention. Marine organisms are a reservoir of anticancer peptides that await discovery. In this study, we aimed to identify cytotoxic oligopeptides from Sarcophyton glaucum. Peptides were purified from among the S. glaucum hydrolysates produced by alcalase, chymotrypsin, papain, and trypsin, guided by a methylthiazolyldiphenyl-tetrazolium bromide(MTT) assay on the human cervical cancer(HeLa) cell line for cytotoxicity evaluation. Purification techniques adopted were membrane ultrafiltration, gel filtration chromatography, solid phase extraction(SPE), and reversed-phase high-performance liquid chromatography(RP-HPLC). Purified peptides were identified by de novo peptide sequencing. From papain hydrolysate, three peptide sequences were identified: AGAPGG, AERQ, and RDTQ(428.45, 502.53, and 518.53 Da, respectively). Peptides synthesized from these sequences exhibited cytotoxicity on HeLa cells with median effect concentration(EC50) values of 8.6, 4.9, and 5.6 mmol/L, respectively, up to 5.8-fold stronger than the anticancer drug 5-fluorouracil. When tested at their respective EC50, AGAPGG, AERQ, and RDTQ showed only 16%, 25%, and 11% cytotoxicity to non-cancerous Hek293 cells, respectively. In conclusion, AERQ, AGAPGG, and RDTQ are promising candidates for future development as peptide-based anticancer drugs.
基金the National Natural Science Foundation of China(32171728 and 22008159)Wuhan Knowledge Innovation Project(2022020801020312).
文摘Developing on-demand biomass valorization represents an ideal path to alleviate the double burden of a sustainable energy-environment future,yet exploring tunable lignin-first chemistry to accomplish multifunctional water purification remains elusive.Herein,we report a versatile solvent-fractionation to construct heteroatom-doped multicolor lignin carbon quantum dots(CQDs)with the functions of bimodal pollutant sensing,metal-ionic visualization,and photocatalytic antibiotic dissociation.With the aid of oxidation cleavage and biphasic extraction,the underlying lignin features of molecular weight and functional linkages influence the quantum size and core-surface state of CQDs conferring the unique optical-structure-performance.The N,S co-doped blue-emitting CQDs via light-quenching offer the selective identification of Fe^(3+)-ions in a broad response range with an acceptable limit of detection.The addition of L-cysteine can efficiently restore the fluorescence of CQDs by forming a stable Fe^(3+)-L-cys complex.The green-emissive CQDs are facilely embedded into cellulose hydrogel to directly visualize the presence of metal-ions.A red-CQDs modified ternary ZnIn2S4(ZIS)composite is fabricated to achieve photocatalytic antibiotic removal with an efficiency of~85%.The excellent photo-generated electron and storage capabilities of CQDs improve the light-capturing,electron conduction,and charge carrier separation of ZIS.The reactive species are of importance to photocatalytic tetracycline oxidation,wherein the electron holes(h+)function as the main contributor followed by∙O_(2)^(-),1O2 and∙OH.The directly interfacial electron escaping-shuttling with the help of optimized electronic and energy-band structures is confirmed via electrochemical test and theoretical computation.We anticipate that the present work not only sheds substantial light to manipulate polychromatic lignin-based CQDs via a tailored solvent-engineering,but also presents an emerging green route of emphasizing biomass-water nexus.
基金supported by the following grants:National Natural Science Foundation of China(Grant Nos.92354305 and 32271428),National Key R&D Program of China(Grant No.2022YFC3401100)Young Talent Program of Hubei Provincial Health Commission(WJ2025Q037)+1 种基金Interdisciplinary Research Program of HUST(Grant No.2023JCY5045)Director Fund of WNLO.
文摘Fluorescent probes,with their superior optical properties and labeling versatility,have greatly advanced the visualization of intracellular molecules and subcellular structures.However,poor cytoplasmic delivery,caused by charge,size,or targeting groups,limits the effective use of many fluorescent probes in live cells.Recently,cell-penetrating peptides(CPPs)have emerged as efficient carriers,offering great potential for the cytoplasmic delivery of fluorescent probes in live cells.This review provides a comprehensive overview of CPPs as vehicles for probe delivery,outlining advances in their development,conjugation chemistries,and intracellular delivery mechanisms.Recent applications in live-cell imaging are highlighted and organized according to major CPP modification strategies,including sequence engineering,cyclization,hybrid design and enhancement by chemical reagents.Finally,the challenges that remain and the future outlook of this rapidly evolvingfield are discussed.
基金support of this study by the National Natural Science Foundation of China(Grant Nos.U22A20173 and U21A2058).
文摘High-quality steel production requires superior-performance refractories.To meet the requirements of quality enhancement and efficiency improvement in the steelmaking industry,the application of the novel microporous magnesia with high strength,remarkable slag resistance,and excellent thermal insulation is promoted.The interface reaction between H13 steel and novel microporous magnesia castable was investigated by using the crucible method,to elucidate the molten steel purification mechanism.The interface microstructure was observed by scanning electron microscopy,and the composition,size,and amount of inclusions were statistically analyzed.A thermal calculation was conducted to gain a deeper understanding of the modification process of inclusions.Fused magnesia castables were used as the blank control.The results show that the average number density and size of inclusions were reduced by 5.99 mm^(−2) and 0.28μm respectively after the same reaction time because the micropores enhanced the inclusion adsorption.The size of inclusions caused by erosion decreased.Also,more[Mg]dissolved into molten steel over 60 min reaction time and resulted in a 0.49 wt.%increase in inclusion Mg content,which modified the inclusion by decreasing their melting point.Therefore,applying novel microporous magnesia was beneficial for purifying H13 steel.
基金supported by the Natural Science Foundation of Jiangsu Province(No.BK20220409)the National Natural Science Foundation of China(No.22401153)+2 种基金the FWO[Fund for Scientific Research-Flanders(Belgium)]for financial support(recipient Erik V.Van der Eycken)the Research Council of the KU Leuven(recipient Erik V.Van der Eycken)the support of the"RUDN University Strategic Academic Leadership Program"(recipient Erik V.Van der Eycken).
文摘Peptides play important roles in chemistry,medicinal chemistry and life science,due to their high efficiency and specificity,unusual biological and therapeutic properties.As naturally occurring peptides often face with their intrinsic limitations including metabolic instability and low membrane permeability,the strategies for synthesizing unnatural amino acids and peptides are explored.Among the methods for modifying amino acids and peptides,chemo-and site-selective approaches are preferred because of the ability to fine-tuning structural features.Recently,transition metal-catalyzed C–H activation has been employed for the functionalization of amino acids and peptides.Through domino C–H activation/annulation,a series of structurally complex and diverse amino acids and peptides is constructed.This review highlights recent advances in the synthesis of unnatural amino acids and peptides via transition metal-catalyzed C–H activation/annulation.
文摘The escalating global crisis of antibiotic resistance necessitates urgent development of novel antimicrobial agents.In this context,antimicrobial peptides(AMPs)derived from fish emerge as a highly promising strategic resource,owing to their unique structural diversity and the exceptional adaptability and tolerance conferred by evolutionary pressures in aquatic environments.This review systematically synthesizes key advances in fish-derived AMP research.It details their diverse sourcing avenues,encompassing tissues from live fish(e.g.,skin,mucus,gills,intestines)and processing byproducts(e.g.,scales,skins,viscera).The discussion covers efficient isolation,purification,and synthesis strategies,and critically examines their defining feature:unique multi-target synergistic antimicrobial mechanisms(including microbial membrane disruption,intracellular targeting,and immunomodulation),which contribute to a reduced propensity for resistance development.To address inherent limitations of natural AMPs(such as susceptibility to proteolysis and potential toxicity),the review highlights innovative optimization approaches,including computational-aided rational design,amino acid modification,cyclization,and hybrid peptide construction.Furthermore,the review elaborates on their significant application potential across crucial domains:food preservation(inhibiting spoilage organisms,extending shelf-life),sustainable aquaculture(as antibiotic alternatives,enhancing disease resistance,improving water quality),and the development of novel anti-infective therapeutics(particularly against drug-resistant infections).Therefore,this work aims to provide a comprehensive theoretical foundation and innovative strategic insights to foster in-depth research and the sustainable exploitation of this vital strategic biological resource.
基金supported by the National Natural Science Foundation of China(No.82104353)China Postdoctoral Science Foundation funded project(No.2022M711680).
文摘Insects represent emerging sources of bioactive peptides and functional materials.Mantidis Oötheca(Sang-Piao-Xiao in Chinese,SPX)serves as an insect-derived medicine for treating kidney disease.This study demonstrated that supernatant(SPX)improved kidney function in adriamycin(ADR)-induced nephropathy mice model.Transcriptomic analysis revealed that SPX inhibited complement activation by targeting the MASP1-C3/C3a receptor(C3aR)pathway.Peptidomic analysis identified 304 peptides from SPX,with 49 peptides selected for evaluation using prediction tools and molecular docking with complement core protein C3.Three peptides(PMGFPFDR,FNDPK,AAQFFNR)exhibiting docking scores below-8.0 were synthesized to verify complement inhibition and anti-fibrotic activities.The synthetic peptide AAQFFNR demonstrated complement inhibitory activity,with an inhibitory complement hemolytic 50%(ICH_(50))value of 24.54μmol·L^(-1),and exhibited superior protective effects in ADR-induced HK-2 cells.Surface plasmon resonance(SPR)assay revealed direct interaction between AAQFFNR and complement C3 with K_(d)value of 16.8μmol·L^(-1).The reno-protective effect of AAQFFNR was subsequently verified in ADR-induced mice.This research provides initial evidence that complement C3-inhibiting peptides from insects demonstrate potential in preventing nephropathy through in silico and in vivo validation approaches.
基金supported by the central government and guides local funds for science and technology development(2022ZY0109).
文摘The naturally fermented Inner Mongolian cheese’s flavor and nutritional value make it a popular choice among customers.In this work,to create multi-functional peptides that have taste and biological activity,peptidomics and bioinformatics were used to screen flavor peptides from Inner Mongolian cheese and further assess their antioxidant and angiotensin I-converting enzyme(ACE)inhibitory properties.According to sensory data,YH8 and IL7 had detectable bitter tastes with low thresholds of 0.03 and 0.06 mmol/L,respectively.With an umami threshold range of 0.24‒0.81 mmol/L,VQ6,FK13,HP13 and QT14 exhibited a range of flavors dominated by umami,including sweet,bitter,salty,sour and kokumi.Antioxidant activity wise,YH8,VQ6,HP13 and QT14 were well represented.The above-mentioned peptides all had some ACE inhibitory effect.The bitter peptide IL7(IC_(50)=0.08 mmol/L)had the highest level of ACE inhibitory activity,followed by YH8(IC_(50)=0.33 mmol/L).These multi-functional peptides,which have been assessed for bioactive and taste features in Inner Mongolian cheese,may have positive impacts on health and harmonize the cheese’s overall flavor.These results suggest that some flavor peptides produced in fermented foods might be with bioactivities while providing a basis for the exploration and application of multi-functional peptides.
基金National Natural Science Foundation of China,No.42171258,No.U22A20611Joint Fund of Hunan Provincial Natural Science Foundation of China,No.2024JJ8350。
文摘The equilibrium between the supply and demand of water purification services is essential for safeguarding watershed ecosystems and supporting sustainable socio-economic growth.While current research mainly emphasizes the static analysis of this balance,dynamic investigations into service flow characteristics remain scarce.This study focuses on the Xiangjiang River Basin in southern China,utilizing the InVEST model,differential equations governing supply and demand,and social network analysis to investigate the spatio-temporal patterns of water purification service supply and demand.The results reveal that between 2000 and 2020,the supply of water purification services showed a slight upward trend,while demand exhibited a fluctuating downward tendency,and the supply-demand surplus fluctuated.On an annual basis,the supply generally met the demand,but significant spatial variation in supply-demand balance was observed,with high-risk zones concentrated in the central Hengshao arid corridor and the northern Changzhutan metropolitan area.In the water purification service network,surplus nodes increased,while deficit nodes decreased over time.Network density improved from 98.96%in 2000 to 100%in 2020.The flow of surplus services from upstream regions alleviated supply-demand imbalances downstream,notably in the Hengyang-Shaoyang(Hengshao)arid corridor and the Changsha-Zhuzhou-Xiangtan(Changzhutan)metropolitan area.However,during drought years,diminished water volume intensified supply-demand pressures in these regions.This research framework,which incorporates the dynamic effects of service flow,broadens the scope of water purification service studies and provides a solid foundation for integrated water resource and environmental management.
