基于离子淌度质谱研究低浓度甘油对蛋白质结构的影响  

Effects of Low Concentration Glycerol on Protein Structure Based on Ion Mobility-Mass Spectrometry

作　　者：何源峰 朱龙平[1] 苗慧[1] 陈宝[1] HE Yuan-feng;ZHU Long-ping;MIAO Hui;CHEN Bao(School of Pharmacy,Sun Yat-sen University,Guangzhou 510006,China)

机构地区：[1]中山大学药学院,广东广州510006

出　　处：《质谱学报》2022年第5期663-669,I0007,共8页Journal of Chinese Mass Spectrometry Society

基　　金：中山大学教学质量与教学改革工程项目(20220500)。

摘　　要：甘油作为水溶液中蛋白质的稳定剂,研究其存在时蛋白质的结构变化对蛋白质相关研究和应用具有重要意义。本研究以牛血清白蛋白(BSA)为模型蛋白,采用离子淌度质谱(IM-MS)法和动态光散射法考察在近似生理条件下低浓度甘油对蛋白质结构的影响。在一定浓度范围内,甘油可引起BSA平均电荷和碰撞截面积(CCS)的增加,单个电荷状态也经历了CCS值的增加,还可导致BSA水化半径的增加,表明低浓度甘油可引起溶液中蛋白质结构松散。此外,含0.5%甘油的BSA去折叠的开始电压较高,且去折叠过渡发生在更宽的电压范围内,表明低浓度甘油可提高蛋白质的稳定性。本工作可为甘油稳定蛋白质的机制研究提供参考。Glycerol is a simple polyol compound,it has many biological and industrial applications when mixed with water.It can stabilize proteins under extreme conditions,such as heat stress,cold shock,high pressure,etc.Most proteins are usually stored in a buffer system with the presence of glycerol after purification to maintain the stability of their biological activity.At present,there are still some controversies about the protective mechanism of glycerol on proteins.Most studies were focused on the effect of high concentrations of glycerol on protein structure.However,there were few related studies on low concentrations of glycerol.Therefore,an in-depth understanding of the effects of low concentrations of glycerol on protein structure is beneficial to protein-related research and applications.Electrospray ionization-mass spectrometry(ESI-MS)has become a commonly used technique to study protein structure and function,which is reliable and time-efficient.Protein conformational change can be described in more detailed by ESI combined with ion mobility spectrometry.Ion mobility provides an additional dimension of resolution.When ions with different sizes,charges and shapes pass through the chamber,they are migrated and separated in neutral media according to the collision cross-section(CCS).By measuring the molecular weight,charge state distribution,drift time and CCS,the structural change information of the protein can be obtained.In this study,bovine serum albumin(BSA)was used as a model protein,and ion mobility-mass spectrometry(IM-MS)and dynamic light scattering were used to investigate the effect of low concentration glycerol on protein structure under approximate physiological conditions.The results showed that glycerol within a certain concentration range could cause an increase in the average charge and CCS of BSA.Meanwhile,a single charge state of BSA also experienced an increase of CCS in presence of glycerol.In addition,the hydration radius of BSA were increased with the increase of glycerol concentration.The

关 键 词：离子淌度质谱(IM-MS) 甘油 牛血清白蛋白(BSA) 蛋白质结构 碰撞截面积(CCS) 

分 类 号：O657.63[理学—分析化学]