Effects of Storage Time and Hydrogen Peroxide on the Formation of Soy Globulin 15S in 11S Dilute Solutions Investigated by Analytical Ultracentrifugation  

基于分析型超速离心研究储存时间以及过氧化氢对大豆15S蛋白形成的影响

作　　者：Hehang Shi Xiaodong Ye 师鹤航;叶晓东(中国科学技术大学化学物理系,合肥230026;中国科学技术大学,中国科学院软物质化学重点实验室,合肥230026)

机构地区：[1]Department of Chemical Physics,University of Science and Technology of China,Hefei 230026,China [2]CAS Key Laboratory of Soft Matter Chemistry,University of Science and Technology of China,Hefei 230026,China

出　　处：《Chinese Journal of Chemical Physics》2024年第4期563-570,I0095,共9页化学物理学报（英文）

基　　金：supported by the National Natural Science Foundation of China(No.22173092 and No.21674107).

摘　　要：Two soy protein 11S fractions with different surface sulfhydryl contents were prepared.Utilizing analytical ultracentrifugation,the effects of storage time and hydrogen peroxide at different concentrations(0.5-100 mmol/L)on the two 11S fractions were investigated.Results show that after removing 2-mercaptoethanol(2-ME)by size exclusion chromatography,the 11S fraction with high surface sulfhydryl content(2.0 mol sulfhydryl/mol 11S)progressively formed 15S and 21S in dilute solutions during storage at 4℃ for 82 days.While,the 11s fraction with low surface sulfhydryl content(0.2 mol sulfhydryl/mol 11S)was stable under the same condition.Moreover,after treating the 11s with high surface sulfhydryl content with 1 mmol/L H_(2)O_(2),the weight percentage of 15S reached the maximum value of 20%.The 15S induced by air and H_(2)O_(2)could be totally converted to 11S with the addition of 10 mmol/L 2-ME,which could be attributed to that the disulfide bond linking two 11S molecules is on the surface of the 15S and easily accessible to the reducing agent 2-ME.This study helps us to deeply understand the formation mechanism of 15S and the stability of 11S.本文制备了两种不同表面巯基含量的11S,基于分析型超速离心研究了储存时间和不同浓度(0.5~100 mmol/L)的过氧化氢对这两种11S的影响.结果表明,用体积排阻色谱除去2-巯基乙醇后,高表面巯基含量(2.0 mol SH/mol 11S)的11S稀溶液在4℃储存82天期间逐渐形成15S和21S.但是,低表面巯基含量(0.2 mol SH/mol 118)的118在相同条件下是稳定的,此外,1 mmol/L H_(2)O_(2)对高表面巯基含量的118处理后,15S的质量分数达到最大值20%,由空气和H_(2)O_(2)诱导形成的15S可以被10mmol/L 2-巯基乙醇完全转化为11S,原因可能是连接两个118分子的二硫键位于15S的表面,容易被还原剂2-巯基乙醇接近.本研究有助于深入理解15S蛋白的形成机理和稳定性.

关 键 词：SOYBEAN 15S globulin 11S Analytical ultracentrifugation Hydrogen peroxide 

分 类 号：TQ936[化学工程]