It was found that phosphorylation of small peptide could improve the sensitivity in mass spectrometry. Density functional theory calculations showed that the energy for the protonation of N-(O,O'-dimethyl) phospho...It was found that phosphorylation of small peptide could improve the sensitivity in mass spectrometry. Density functional theory calculations showed that the energy for the protonation of N-(O,O'-dimethyl) phosphoryl glycylglycine is lower than that of glycylglycine. These could help to understanding the experimental results.展开更多
Non-steroidal anti-inflammatory drugs（NSAIDs） were able to produce tissue damage and oxidative stress in animal models of small intestinal damage. In this study, the putative protective effect of wheat peptides was ...Non-steroidal anti-inflammatory drugs（NSAIDs） were able to produce tissue damage and oxidative stress in animal models of small intestinal damage. In this study, the putative protective effect of wheat peptides was evaluated in a NSAID-induced small intestinal damage model in rats, different doses of wheat peptides or distilled water were administered daily by intragastric administration for 30 d until small intestinal damage was caused. Before sacrificing, NSAIDs（aspirin and indomethacin） or physiological saline were infused into the digestive tract twice. Wheat peptides administration reduced edema and small intestinal damage, and significantly decreased the level of tumor necrosis factor（TNF）-α in mucous membrane of small intestine. Oxidative stress was significantly increased after NSAID infusion and was reduced by wheat peptides. Wheat peptides increased glutathione peroxidase（GSH-Px） activity in mucous membrane of small intestine. μ-Opioid receptor mRNA expression decreased more significantly in wheat peptides treated rats than in the model control group. Overall, the results suggest that non-steroidal anti-inflammatory drugs induced small intestinal damage in rats and wheat peptides administration may be an effective tool for protecting small intestinal tissue against NSAID-induced small intestinal damage and oxidative stress.展开更多
The aim of this study was to investigate the effect of duodenal infusion of soybean small peptides(SSP) on mammary uptake of amino acids(AA).Eight Chinese Saanen goats with duodenal fistulae and catheters were used in...The aim of this study was to investigate the effect of duodenal infusion of soybean small peptides(SSP) on mammary uptake of amino acids(AA).Eight Chinese Saanen goats with duodenal fistulae and catheters were used in a crossover design trial.Goats were infused with 0,60,120,180 g/d SSP.The experimental period lasted for 14 d.The results showed:1) milk protein yield and content were increased,with the increment in milk protein yield being significant(P【0.05).Milk fat yield and content were decreased with the increased amount of SSP infused(P【0.05).2) Mammary plasma flow was not changed(P】0.05) by SSP infusion though the average was slightly higher.Mammary plasma flow/milk yield was decreased by SSP infusion and there was significant difference between the 120 g/d treatment and the control(P【0.05).3) Compared with the control treatment,uptakes of most free amino acids were increased in the 60 and 120 g/d treatments,but decreased by the 180 g/d treatment.The uptakes of all peptide-bound essential amino acids(PB-EAA) were increased except for PB-Ile.Uptake of PB-Val,PB-Leu, PB-Phe,PB-Thr,PB-Met and PB-Lys was highest in the 120 g/d treatment.Among the peptide-bound nonessential amino acids(PB-NEAA),uptake of PB-Ser,PB-Tyr,and PB-Pro was increased(P【0.05) while that of PB-Gly was decreased(P】0.05).4) With the exception of Lys,secretion of all essential AA(EAA) was increased by SSP infusion from 0-120 g/d(P【0.05),while in the 180 g/d treatment the increase was not significant and was lower than that in the 120 g/d treatment.5) The expression of APN was increased by SSP;in the 60,120,180 g/d treatments expression was 13.55-,18.69-,and 10.01-fold over that of the controls.Conclusion:SSP might be used as substrates for milk protein synthesis by mammary gland,and can increase synthesis and secretion of milk protein.There was reason to believe that uptake and use of AA was either saturated or inhibited at high levels of infusion of SSP.Increased APN expression with infusion of SSP related to mammary uptake of PBAA by mammary gland,which suggested that APN was one of the peptidases regulating use of AA from small peptides in mammary tissue.展开更多
[Objective]The paper was to study effects of small peptide chelated trace elements(copper,iron,zinc and manganese)on growth performance,chicken quality and antioxidant capacity of rapid yellow feather broilers.[Method...[Objective]The paper was to study effects of small peptide chelated trace elements(copper,iron,zinc and manganese)on growth performance,chicken quality and antioxidant capacity of rapid yellow feather broilers.[Method]Three hundred one-day-old yellow feather broilers with similar body weight were selected and randomly divided into three treatments:inorganic trace element group(basal diet+inorganic trace elements),organic trace element group(basal diet+small peptide chelated trace elements)and compound group(basal diet+50%inorganic trace elements+50%small peptide chelated trace elements).There were 10 replicates per treatment and 10 chickens per replicate.The trial lasted for 63 d.[Result]①Compared to inorganic trace element group,average daily gain(ADG)of yellow feather broilers in organic trace element group was significantly increased over the whole period(P<0.05).②There was no significant difference in slaughter performance and immune organ indices among the three test groups(P>0.05).③There was no significant difference in breast muscle pH,chicken color,drip loss,and shear force among the three groups(P>0.05),but cooking loss of chicken breast in inorganic trace element group was 27.46%and 22.53%higher than those in organic trace element group and compound group,respectively(P<0.05).④MDA content in serum in organic trace element group was 15.61%lower than that in inorganic trace element group(P<0.05).[Conclusion]Complete substitution of inorganic copper,iron,zinc and manganese by small peptide chelated copper,iron,zinc,and manganese significantly increases ADG of broilers,improves quality of chicken breast,and enhances antioxidant capacity.展开更多
Neuropeptide and chemokine receptors of the G protein-coupled receptor (GPCR) family belong to different classes and subgroups providing different docking sites and special binding behavior at extracellular and also t...Neuropeptide and chemokine receptors of the G protein-coupled receptor (GPCR) family belong to different classes and subgroups providing different docking sites and special binding behavior at extracellular and also transmembrane domains for small molecules potentially suitable for positron emission tomography (PET). The contribution gives an overview updating developments of small-molecule, nonpeptide ligands at a selection of peptide and chemokine receptors, expressed in neurons and microglia of the brain, regarding the last five years. Orexin 1 and orexin 2 receptors (OX1R;OX2R) and neuropeptide Y1 and Y2 receptors (NPY1R, NPY2R) were chosen as representatives of Class A neuropeptide receptors, chemokine receptor CX3C (CX3CR1) as Class A, protein-activated receptor, highly expressed in activated microglia, and corticotropin releasing factor receptor 1 (CRFR1) as representative Class B1 receptor. Structural differences between binding domains and their endogenous ligands as well as parallel expression in different types of cells and generally low density of these receptors in brain tissue are factors making the search for selective and sensitive ligands more difficult than for classical GPCR receptors. Main progress in ligand development is observed for NPY receptor antagonists and orexin receptor antagonists. For orexin receptors, search for suitable ligands can be supported with modelling approaches, as recently the complete molecular structure of these receptors is available. Small molecules, binding at CRFR1, as for other Class B1 receptor ligands, in PET and investigations of pharmacodynamics revealed rather allosteric binding modes, although, the complete crystal structure of CRFR1 as prototype of Class B1 provides, hitherto, improved possibilities for understanding binding mechanisms. Highly specific as a marker of microglia among?the GPCRs, CX3CR1 is focused as target of PET during inflammation of brain and spinal cord.展开更多
This study aims at the effects of an intake of low molecular weight corn peptides(LMCPs) prepared from zein on alcohol metablism in rats. LMCPs(1.0 g/kg body weight) in 15% ethanol(10 mL/kg body weight) were given to ...This study aims at the effects of an intake of low molecular weight corn peptides(LMCPs) prepared from zein on alcohol metablism in rats. LMCPs(1.0 g/kg body weight) in 15% ethanol(10 mL/kg body weight) were given to Wister rats by intragastric gavage. The assay of blood ethanol was conducted by using the enzyme based assay kit. The amino acid analysis was made with an amino acid analyzer. The data of the animal experiments showed that LMCPs could accelerate the metabolism of alcohol in rats. In the control group, the blood ethanol concentration reached the maximum level of (827.0±77.3) mg/L after ethanol loading for 30 min, then gradually decreased. In contrast, the blood ethanol concentration only reached (527.25±47.0) mg/L after 30 min in the group of LMCPs taken. These results indicate that LMCPs could decrease ethanol concentration in blood rapidly.展开更多
AIM: To investigate if non-peptidic small molecular inhibitors of the p53-HDM2 interaction could restore p53 function and kill tumor cells.METHODS: A series of non-peptidic small HDM2 inhibitors were designed by compu...AIM: To investigate if non-peptidic small molecular inhibitors of the p53-HDM2 interaction could restore p53 function and kill tumor cells.METHODS: A series of non-peptidic small HDM2 inhibitors were designed by computer-aided model and synthesized by chemical method. Syl-155 was one of these inhibitors. Cytotoxic effect of syl-155 on three tumor cell lines with various states of p53, HT1080 (wild-type p53), KYSE510 (mutant p53), MG63 (p53 deficiency) was evaluated by MTT assay, Western blot and flow cytometry.RESULTS: Syl-155 stimulated the accumulation of p53 and p21 protein in HT1080 cells expressing wild-type p53, but not in KYSE510 and MG63 cells. Consequently, syl-155 induced cell cycle arrest and apoptosis in HT1080 cells.CONCLUSION: Non-peptidic small molecular inhibitors of the p53-HDM2 interaction show promise in treatment of tumors expressing wild-type p53.展开更多
The characteristic distribution of calcitonin gone-related peptide(CGRP)inthe small intestine of rats and its changes in acute intestinal radiation sickness(AIRS)were studied with immunocytochemistry(whole mount stret...The characteristic distribution of calcitonin gone-related peptide(CGRP)inthe small intestine of rats and its changes in acute intestinal radiation sickness(AIRS)were studied with immunocytochemistry(whole mount stretch preparations of the smallintestine and cryostat sections)and radio-immunoassay.It was found that in all the lay-ers of the intestinal walls,there were large amounts of CGRP immunoreactive(CGRP-I)nerve fibers which existed in especiaUy high density in the myenteric,submucosal andmucosal plexuses.There was also a rather high density of the nerves around the smallvessels of the small intestine and the intestinal crypts.Some CGRP-I neurons were seenin the myenteric and submucosal plexuses.In AIRS,the intestinal CGRP showed a dip-hasic change,in a lower level in the 24th h and a higher level in the 48th and 72nd h af-ter irradiation.The results indicate that CGRP may be related to the regulation of the motility,se-cretion,absorption,sensation,and regional blood flow of the gastrointestinal tract.Pro-bably,CGRP is released under the stress of AIRS and participates in the mechanism ofinjury through many ways especially through the influence on the regional blood flowand the increase of the permeability of blood vessels.展开更多
This study discusses the composition analysis and comparison of Jaboticaba under different processing conditions for fermented liquid, jam, fruit powder, and fruit vinegar. The differences and comparison of the conten...This study discusses the composition analysis and comparison of Jaboticaba under different processing conditions for fermented liquid, jam, fruit powder, and fruit vinegar. The differences and comparison of the contents of total polyphenols, anthocyanins, resveratrol, superoxide dismutase, small molecular peptides and ellagic acid in their products were analyzed. After analysis and comparison of results, the content of total polyphenols was found to be the highest 44.82 ± 0.89 (mg/g) after being fermented directly from fresh fruit. The fresh fruit was dried at low temperature and ground into powder, with a maximum ellagic acid content of 12.799 ± 0.12 (mg/g). Fresh fruit was then made into jam, with the highest anthocyanin content of 57.39 ± 1.20 (mg/g). The fruit vinegar was produced by fermentation. Except for the content of small molecule peptides, which was similar to the content of fermentation broth and fruit powder, they were 20.63 ± 1.61, 23.84 ± 2.51 and 20.52 ± 1.21 (mg/g), and the rest of the composition was not as good as other samples. In the fresh fruit fermentation broth samples, resveratrol was produced and detected, and its content was 2.14 (mg/L), while it was not detected in other samples, and a superoxide dismutase (SOD)-like enzyme was detected in the fresh fruit fermentation broth. The highest activity was 49002.5 units/mL. Jaboticaba is prepared using a fermentation broth processing method with fresh fruit, and its total polyphenol content is higher than that of fruit powder, jam, and fruit vinegar. The commercial value of Jaboticaba and the establishment of composition content data are relatively improved, which is more promising for the future.展开更多
基金The authors thank the National Natural Science Foundation of China(No.39870415)the Ministry of Science and Technology of China,the Education Ministry of China and Tsinghua University for financial suport.
文摘It was found that phosphorylation of small peptide could improve the sensitivity in mass spectrometry. Density functional theory calculations showed that the energy for the protonation of N-(O,O'-dimethyl) phosphoryl glycylglycine is lower than that of glycylglycine. These could help to understanding the experimental results.
基金sponsored by grants from Postgraduates Scientific Research and Innovation Projects in JiangsuProvince,China(CXZZ12_0124)
文摘Non-steroidal anti-inflammatory drugs（NSAIDs） were able to produce tissue damage and oxidative stress in animal models of small intestinal damage. In this study, the putative protective effect of wheat peptides was evaluated in a NSAID-induced small intestinal damage model in rats, different doses of wheat peptides or distilled water were administered daily by intragastric administration for 30 d until small intestinal damage was caused. Before sacrificing, NSAIDs（aspirin and indomethacin） or physiological saline were infused into the digestive tract twice. Wheat peptides administration reduced edema and small intestinal damage, and significantly decreased the level of tumor necrosis factor（TNF）-α in mucous membrane of small intestine. Oxidative stress was significantly increased after NSAID infusion and was reduced by wheat peptides. Wheat peptides increased glutathione peroxidase（GSH-Px） activity in mucous membrane of small intestine. μ-Opioid receptor mRNA expression decreased more significantly in wheat peptides treated rats than in the model control group. Overall, the results suggest that non-steroidal anti-inflammatory drugs induced small intestinal damage in rats and wheat peptides administration may be an effective tool for protecting small intestinal tissue against NSAID-induced small intestinal damage and oxidative stress.
文摘The aim of this study was to investigate the effect of duodenal infusion of soybean small peptides(SSP) on mammary uptake of amino acids(AA).Eight Chinese Saanen goats with duodenal fistulae and catheters were used in a crossover design trial.Goats were infused with 0,60,120,180 g/d SSP.The experimental period lasted for 14 d.The results showed:1) milk protein yield and content were increased,with the increment in milk protein yield being significant(P【0.05).Milk fat yield and content were decreased with the increased amount of SSP infused(P【0.05).2) Mammary plasma flow was not changed(P】0.05) by SSP infusion though the average was slightly higher.Mammary plasma flow/milk yield was decreased by SSP infusion and there was significant difference between the 120 g/d treatment and the control(P【0.05).3) Compared with the control treatment,uptakes of most free amino acids were increased in the 60 and 120 g/d treatments,but decreased by the 180 g/d treatment.The uptakes of all peptide-bound essential amino acids(PB-EAA) were increased except for PB-Ile.Uptake of PB-Val,PB-Leu, PB-Phe,PB-Thr,PB-Met and PB-Lys was highest in the 120 g/d treatment.Among the peptide-bound nonessential amino acids(PB-NEAA),uptake of PB-Ser,PB-Tyr,and PB-Pro was increased(P【0.05) while that of PB-Gly was decreased(P】0.05).4) With the exception of Lys,secretion of all essential AA(EAA) was increased by SSP infusion from 0-120 g/d(P【0.05),while in the 180 g/d treatment the increase was not significant and was lower than that in the 120 g/d treatment.5) The expression of APN was increased by SSP;in the 60,120,180 g/d treatments expression was 13.55-,18.69-,and 10.01-fold over that of the controls.Conclusion:SSP might be used as substrates for milk protein synthesis by mammary gland,and can increase synthesis and secretion of milk protein.There was reason to believe that uptake and use of AA was either saturated or inhibited at high levels of infusion of SSP.Increased APN expression with infusion of SSP related to mammary uptake of PBAA by mammary gland,which suggested that APN was one of the peptidases regulating use of AA from small peptides in mammary tissue.
文摘[Objective]The paper was to study effects of small peptide chelated trace elements(copper,iron,zinc and manganese)on growth performance,chicken quality and antioxidant capacity of rapid yellow feather broilers.[Method]Three hundred one-day-old yellow feather broilers with similar body weight were selected and randomly divided into three treatments:inorganic trace element group(basal diet+inorganic trace elements),organic trace element group(basal diet+small peptide chelated trace elements)and compound group(basal diet+50%inorganic trace elements+50%small peptide chelated trace elements).There were 10 replicates per treatment and 10 chickens per replicate.The trial lasted for 63 d.[Result]①Compared to inorganic trace element group,average daily gain(ADG)of yellow feather broilers in organic trace element group was significantly increased over the whole period(P<0.05).②There was no significant difference in slaughter performance and immune organ indices among the three test groups(P>0.05).③There was no significant difference in breast muscle pH,chicken color,drip loss,and shear force among the three groups(P>0.05),but cooking loss of chicken breast in inorganic trace element group was 27.46%and 22.53%higher than those in organic trace element group and compound group,respectively(P<0.05).④MDA content in serum in organic trace element group was 15.61%lower than that in inorganic trace element group(P<0.05).[Conclusion]Complete substitution of inorganic copper,iron,zinc and manganese by small peptide chelated copper,iron,zinc,and manganese significantly increases ADG of broilers,improves quality of chicken breast,and enhances antioxidant capacity.
文摘Neuropeptide and chemokine receptors of the G protein-coupled receptor (GPCR) family belong to different classes and subgroups providing different docking sites and special binding behavior at extracellular and also transmembrane domains for small molecules potentially suitable for positron emission tomography (PET). The contribution gives an overview updating developments of small-molecule, nonpeptide ligands at a selection of peptide and chemokine receptors, expressed in neurons and microglia of the brain, regarding the last five years. Orexin 1 and orexin 2 receptors (OX1R;OX2R) and neuropeptide Y1 and Y2 receptors (NPY1R, NPY2R) were chosen as representatives of Class A neuropeptide receptors, chemokine receptor CX3C (CX3CR1) as Class A, protein-activated receptor, highly expressed in activated microglia, and corticotropin releasing factor receptor 1 (CRFR1) as representative Class B1 receptor. Structural differences between binding domains and their endogenous ligands as well as parallel expression in different types of cells and generally low density of these receptors in brain tissue are factors making the search for selective and sensitive ligands more difficult than for classical GPCR receptors. Main progress in ligand development is observed for NPY receptor antagonists and orexin receptor antagonists. For orexin receptors, search for suitable ligands can be supported with modelling approaches, as recently the complete molecular structure of these receptors is available. Small molecules, binding at CRFR1, as for other Class B1 receptor ligands, in PET and investigations of pharmacodynamics revealed rather allosteric binding modes, although, the complete crystal structure of CRFR1 as prototype of Class B1 provides, hitherto, improved possibilities for understanding binding mechanisms. Highly specific as a marker of microglia among?the GPCRs, CX3CR1 is focused as target of PET during inflammation of brain and spinal cord.
基金Supported by the Grant 94 35 4 6 - 3from Science and Technology Commission of Jilin Province
文摘This study aims at the effects of an intake of low molecular weight corn peptides(LMCPs) prepared from zein on alcohol metablism in rats. LMCPs(1.0 g/kg body weight) in 15% ethanol(10 mL/kg body weight) were given to Wister rats by intragastric gavage. The assay of blood ethanol was conducted by using the enzyme based assay kit. The amino acid analysis was made with an amino acid analyzer. The data of the animal experiments showed that LMCPs could accelerate the metabolism of alcohol in rats. In the control group, the blood ethanol concentration reached the maximum level of (827.0±77.3) mg/L after ethanol loading for 30 min, then gradually decreased. In contrast, the blood ethanol concentration only reached (527.25±47.0) mg/L after 30 min in the group of LMCPs taken. These results indicate that LMCPs could decrease ethanol concentration in blood rapidly.
基金Supported by the China Key Program on Basic Research,G1998051102 and G1998051021 National Science Foundation of China, 39870862
文摘AIM: To investigate if non-peptidic small molecular inhibitors of the p53-HDM2 interaction could restore p53 function and kill tumor cells.METHODS: A series of non-peptidic small HDM2 inhibitors were designed by computer-aided model and synthesized by chemical method. Syl-155 was one of these inhibitors. Cytotoxic effect of syl-155 on three tumor cell lines with various states of p53, HT1080 (wild-type p53), KYSE510 (mutant p53), MG63 (p53 deficiency) was evaluated by MTT assay, Western blot and flow cytometry.RESULTS: Syl-155 stimulated the accumulation of p53 and p21 protein in HT1080 cells expressing wild-type p53, but not in KYSE510 and MG63 cells. Consequently, syl-155 induced cell cycle arrest and apoptosis in HT1080 cells.CONCLUSION: Non-peptidic small molecular inhibitors of the p53-HDM2 interaction show promise in treatment of tumors expressing wild-type p53.
文摘The characteristic distribution of calcitonin gone-related peptide(CGRP)inthe small intestine of rats and its changes in acute intestinal radiation sickness(AIRS)were studied with immunocytochemistry(whole mount stretch preparations of the smallintestine and cryostat sections)and radio-immunoassay.It was found that in all the lay-ers of the intestinal walls,there were large amounts of CGRP immunoreactive(CGRP-I)nerve fibers which existed in especiaUy high density in the myenteric,submucosal andmucosal plexuses.There was also a rather high density of the nerves around the smallvessels of the small intestine and the intestinal crypts.Some CGRP-I neurons were seenin the myenteric and submucosal plexuses.In AIRS,the intestinal CGRP showed a dip-hasic change,in a lower level in the 24th h and a higher level in the 48th and 72nd h af-ter irradiation.The results indicate that CGRP may be related to the regulation of the motility,se-cretion,absorption,sensation,and regional blood flow of the gastrointestinal tract.Pro-bably,CGRP is released under the stress of AIRS and participates in the mechanism ofinjury through many ways especially through the influence on the regional blood flowand the increase of the permeability of blood vessels.
文摘This study discusses the composition analysis and comparison of Jaboticaba under different processing conditions for fermented liquid, jam, fruit powder, and fruit vinegar. The differences and comparison of the contents of total polyphenols, anthocyanins, resveratrol, superoxide dismutase, small molecular peptides and ellagic acid in their products were analyzed. After analysis and comparison of results, the content of total polyphenols was found to be the highest 44.82 ± 0.89 (mg/g) after being fermented directly from fresh fruit. The fresh fruit was dried at low temperature and ground into powder, with a maximum ellagic acid content of 12.799 ± 0.12 (mg/g). Fresh fruit was then made into jam, with the highest anthocyanin content of 57.39 ± 1.20 (mg/g). The fruit vinegar was produced by fermentation. Except for the content of small molecule peptides, which was similar to the content of fermentation broth and fruit powder, they were 20.63 ± 1.61, 23.84 ± 2.51 and 20.52 ± 1.21 (mg/g), and the rest of the composition was not as good as other samples. In the fresh fruit fermentation broth samples, resveratrol was produced and detected, and its content was 2.14 (mg/L), while it was not detected in other samples, and a superoxide dismutase (SOD)-like enzyme was detected in the fresh fruit fermentation broth. The highest activity was 49002.5 units/mL. Jaboticaba is prepared using a fermentation broth processing method with fresh fruit, and its total polyphenol content is higher than that of fruit powder, jam, and fruit vinegar. The commercial value of Jaboticaba and the establishment of composition content data are relatively improved, which is more promising for the future.
