目的探讨Lys-C胰蛋白酶在国际临床化学组织(International Federation of Clinical Chemistry and Laboratory Medicine,IFCC)推荐的质谱法测定糖化血红蛋白的参考方法中的应用价值。方法分别用两种特异性蛋白水解酶(GLU-C胞内蛋白酶和L...目的探讨Lys-C胰蛋白酶在国际临床化学组织(International Federation of Clinical Chemistry and Laboratory Medicine,IFCC)推荐的质谱法测定糖化血红蛋白的参考方法中的应用价值。方法分别用两种特异性蛋白水解酶(GLU-C胞内蛋白酶和Lys-C胰蛋白酶)酶解血红蛋白后,进行SDS-PAGE电泳,衡量蛋白酶解的效率,再将消化后的血红蛋白进行质谱分析,测定标本中糖化血红蛋白的浓度。结果在相同的电泳条件下,Lys-C胰蛋白酶酶解血红蛋白的效率优于GLU-C;酶解后的血红蛋白标本经质谱方法分析可知,两种蛋白酶用于检测糖化血红蛋白浓度时,可以得到基本一致的结果,由两种方法绘制的标准曲线r2分别为0.929和0.998。结论在IFCC推荐的糖化血红的蛋白参考测量方法中,一直使用GLU-C胞内蛋白酶酶解血红蛋白,该研究尝试通过Lys-C胰蛋白酶的使用,降低整个实验成本。经结果分析,证实应用这两种特异性的蛋白酶检测糖化血红蛋白时,可以得到基本一致的结果,推荐使用文中所列方法将Lys-C胰蛋白酶作为酶解糖化血红蛋白的特异性蛋白酶。展开更多
TP-5 and Thy(1, synthesized by solid phase synthesis, have the effect to restrain the formation of superoxide anion in xanthine oxidase system in vitro. The formations of lipid peroxide in several organs (such as live...TP-5 and Thy(1, synthesized by solid phase synthesis, have the effect to restrain the formation of superoxide anion in xanthine oxidase system in vitro. The formations of lipid peroxide in several organs (such as liver, brain and thymus) of the mice treated with TP-5, TP-5(R, active fragment of Thy(1 and active fragment of Thy(1(R of 10 (g(kg(d-1 for 10 d were decreased. That means these peptides possess the capability of antioxidezation.展开更多
Insulin controls hyperglycemia caused by diabetes,and virtually all treatments require exogenous insulin. The monomeric B27 Lys destripeptide insulin has 80% bioactivity of wild type. It is a potential drug for clinic...Insulin controls hyperglycemia caused by diabetes,and virtually all treatments require exogenous insulin. The monomeric B27 Lys destripeptide insulin has 80% bioactivity of wild type. It is a potential drug for clinic. But the yield of monomeric B27 Lys destripeptide insulin is limited, because monomeric B27 Lys destripeptide insulin precursor( MIP) was easily to form inclusion body,when MIP is expressed in E. coli. The precursor,MIP,is not only fused to an N-terminal HIS-small ubiquitin-related modifier( SUMO) tag,but also added five Arginine( 5 R) at the C-terminal,which can improve the solubility of the fusion protein. By this way,the yield of fusion protein has been up to 1. 45 mg/L cell culture.This work set up the foundation for the clinical application of B27 Lys destripeptide insulin.展开更多
Background:Over the last decade,the nutritional requirements of lactating modern genotype sows have increased.The current nutritional recommendations might be unable to meet the needs of increased litter size and milk...Background:Over the last decade,the nutritional requirements of lactating modern genotype sows have increased.The current nutritional recommendations might be unable to meet the needs of increased litter size and milk production,and thus the nutritional requirements need to be re-evaluated.The current study was conducted to investigate the effects of dietary methionine to lysine(Met:Lys)ratios on the performance of and methionine metabolism in lactating sows.Results:During the 1st week of lactation,piglets reared on sows in the 0.37 to 0.57 Met:Lys ratio groups grew faster than those reared on sows in the control group(0.27)(P<0.01).The 0.37-ratio group showed increased levels of GSHPx in plasma during lactation(P<0.01)and decreased concentrations of urea nitrogen in the plasma of sows(P<0.05).Compared with the 0.27-ratio group,the levels of T-AOC and GSH-Px in the plasma and homocysteine in the milk of lactating sows were significantly increased in sows in the 0.47-ratio group(P<0.01).In sows fed a 0.57-ratio diet,the levels of glutathione and taurine in the plasma and milk were improved significantly during lactation.However,the content of TBARS in the blood(P<0.05 at day 7 and P=0.06 at weaning day)was increased(P<0.01).Moreover,there were linear increases in the levels of homocysteine in the blood and milk of sows during the lactation period(P<0.01)with increased dietary Met:Lys ratios in the lactation diet.Conclusions:The current study indicated that increasing the dietary Met:Lys ratio(0.37~0.57)in the lactation diet had no significant effect on the overall performance of sows or the colostrum and milk composition,but it increased piglet mean BW and piglet ADG during the first week of lactation.Increasing dietary methionine levels had no significant effect on antioxidant function in lactation sows,even though it increased levels of GSH and GSH-Px in the plasma of sows during lactation.However,the content of homocysteine in the plasma and milk increased during lactation due to a high level of dietary methionine.展开更多
文摘目的探讨Lys-C胰蛋白酶在国际临床化学组织(International Federation of Clinical Chemistry and Laboratory Medicine,IFCC)推荐的质谱法测定糖化血红蛋白的参考方法中的应用价值。方法分别用两种特异性蛋白水解酶(GLU-C胞内蛋白酶和Lys-C胰蛋白酶)酶解血红蛋白后,进行SDS-PAGE电泳,衡量蛋白酶解的效率,再将消化后的血红蛋白进行质谱分析,测定标本中糖化血红蛋白的浓度。结果在相同的电泳条件下,Lys-C胰蛋白酶酶解血红蛋白的效率优于GLU-C;酶解后的血红蛋白标本经质谱方法分析可知,两种蛋白酶用于检测糖化血红蛋白浓度时,可以得到基本一致的结果,由两种方法绘制的标准曲线r2分别为0.929和0.998。结论在IFCC推荐的糖化血红的蛋白参考测量方法中,一直使用GLU-C胞内蛋白酶酶解血红蛋白,该研究尝试通过Lys-C胰蛋白酶的使用,降低整个实验成本。经结果分析,证实应用这两种特异性的蛋白酶检测糖化血红蛋白时,可以得到基本一致的结果,推荐使用文中所列方法将Lys-C胰蛋白酶作为酶解糖化血红蛋白的特异性蛋白酶。
文摘TP-5 and Thy(1, synthesized by solid phase synthesis, have the effect to restrain the formation of superoxide anion in xanthine oxidase system in vitro. The formations of lipid peroxide in several organs (such as liver, brain and thymus) of the mice treated with TP-5, TP-5(R, active fragment of Thy(1 and active fragment of Thy(1(R of 10 (g(kg(d-1 for 10 d were decreased. That means these peptides possess the capability of antioxidezation.
基金China Postdoctoral Science Foundation Projects(No.2015M571455)National Undergraduate Training Program for Innovation and Entrepreneurship,China(No.17T10509)
文摘Insulin controls hyperglycemia caused by diabetes,and virtually all treatments require exogenous insulin. The monomeric B27 Lys destripeptide insulin has 80% bioactivity of wild type. It is a potential drug for clinic. But the yield of monomeric B27 Lys destripeptide insulin is limited, because monomeric B27 Lys destripeptide insulin precursor( MIP) was easily to form inclusion body,when MIP is expressed in E. coli. The precursor,MIP,is not only fused to an N-terminal HIS-small ubiquitin-related modifier( SUMO) tag,but also added five Arginine( 5 R) at the C-terminal,which can improve the solubility of the fusion protein. By this way,the yield of fusion protein has been up to 1. 45 mg/L cell culture.This work set up the foundation for the clinical application of B27 Lys destripeptide insulin.
基金financially supported by the National Key Research and Development Project of China(NO.2018YFD0501003)China Agriculture Research System(NO.CARS-36)+1 种基金Hubei Provincial Creative Team Project of Agricultural Science and Technology(No.2007–620)Fundamental Research Funds for the Central Universities of China(NO.2662017PY017).
文摘Background:Over the last decade,the nutritional requirements of lactating modern genotype sows have increased.The current nutritional recommendations might be unable to meet the needs of increased litter size and milk production,and thus the nutritional requirements need to be re-evaluated.The current study was conducted to investigate the effects of dietary methionine to lysine(Met:Lys)ratios on the performance of and methionine metabolism in lactating sows.Results:During the 1st week of lactation,piglets reared on sows in the 0.37 to 0.57 Met:Lys ratio groups grew faster than those reared on sows in the control group(0.27)(P<0.01).The 0.37-ratio group showed increased levels of GSHPx in plasma during lactation(P<0.01)and decreased concentrations of urea nitrogen in the plasma of sows(P<0.05).Compared with the 0.27-ratio group,the levels of T-AOC and GSH-Px in the plasma and homocysteine in the milk of lactating sows were significantly increased in sows in the 0.47-ratio group(P<0.01).In sows fed a 0.57-ratio diet,the levels of glutathione and taurine in the plasma and milk were improved significantly during lactation.However,the content of TBARS in the blood(P<0.05 at day 7 and P=0.06 at weaning day)was increased(P<0.01).Moreover,there were linear increases in the levels of homocysteine in the blood and milk of sows during the lactation period(P<0.01)with increased dietary Met:Lys ratios in the lactation diet.Conclusions:The current study indicated that increasing the dietary Met:Lys ratio(0.37~0.57)in the lactation diet had no significant effect on the overall performance of sows or the colostrum and milk composition,but it increased piglet mean BW and piglet ADG during the first week of lactation.Increasing dietary methionine levels had no significant effect on antioxidant function in lactation sows,even though it increased levels of GSH and GSH-Px in the plasma of sows during lactation.However,the content of homocysteine in the plasma and milk increased during lactation due to a high level of dietary methionine.
