醇类（甲醇、甘油）和聚乙二醇（PEG-300）对羊肝半胱氨酸蛋白酶抑制剂酸变性状态的比较影响。

Comparative effects of alcohols (methanol, glycerol) and polyethylene glycol (PEG-300) on acid denatured state of goat liver cystatin.

机构信息

Department of biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh 202002, India.

出版信息

J Fluoresc. 2011 Jul;21(4):1401-7. doi: 10.1007/s10895-010-0823-x. Epub 2011 Jan 18.

Abstract

This report summarizes the effect of methanol, glycerol and polyol (PEG) on the acid induced state of goat liver cystatin by various spectroscopic techniques. Native goat liver cystatin (LC) has a fluorescence maximum at 340 nm, whereas the acid induced state shows a red shift of 15 nm with enhanced fluorescence intensity. Addition of 80% (V/V) methanol and glycerol both were found to stabilise the acid induced state of goat liver cystatin. However, glycerol was found to be a better stabilising agent than methanol. The unfolded state of liver cystatin obtained at pH 2 underwent a series of conformational changes when exposed to PEG-300 at varying concentrations. Tertiary structure was stabilized only at low concentrations of PEG-300 but higher concentrations resulted in the loss of tertiary structure.

摘要

本报告总结了甲醇、甘油和多元醇（PEG）通过各种光谱技术对酸诱导状态下羊肝半胱氨酸蛋白酶抑制剂的影响。天然羊肝半胱氨酸蛋白酶抑制剂（LC）的荧光最大发射波长在 340nm 处，而酸诱导状态下的荧光最大发射波长发生了 15nm 的红移，荧光强度增强。发现 80%（V/V）甲醇和甘油都能稳定酸诱导状态下的羊肝半胱氨酸蛋白酶抑制剂。然而，甘油比甲醇更能稳定该状态。在 pH 值为 2 时，肝半胱氨酸蛋白酶抑制剂的展开状态在暴露于不同浓度的 PEG-300 时会发生一系列构象变化。在低浓度的 PEG-300 下，三级结构得到稳定，但在较高浓度下，三级结构会丧失。