阴离子磷脂诱导的β-乳球蛋白的构象变化

Conformational changes of beta-lactoglobulin induced by anionic phospholipid.

作者信息

Liu Xiaohua, Shang Li, Jiang Xiue, Dong Shaojun, Wang Erkang

机构信息

State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Renmin Street 5625, Changchun, Jilin 130022, China.

出版信息

Biophys Chem. 2006 Jun 1;121(3):218-23. doi: 10.1016/j.bpc.2005.12.015. Epub 2006 Feb 21.

DOI:10.1016/j.bpc.2005.12.015

PMID:16494994

Abstract

Conformational changes of beta-lactoglobulin (beta-LG) induced by anionic phospholipid (dimyristoylphosphatidylglycerol, DMPG) at physiological conditions (pH 7.0) have been investigated by UV-VIS, circular dichroism (CD) and fluorescence spectra. The experimental results suggest that beta-LG-DMPG interactions cause beta-LG a structural reorganization of the secondary structure elements accompanied by an increase in alpha-helical content, and a loosening of the protein tertiary structure. The interaction forces between beta-LG and DMPG are further evaluated by fluorescence spectra. The fluorescence spectral data show that conformational changes in the protein are driven by electrostatic interaction at first, then by hydrophobic interaction between a protein with a negative net charge and a negatively charged phospholipid.

摘要

在生理条件（pH 7.0）下，通过紫外可见光谱、圆二色光谱（CD）和荧光光谱研究了阴离子磷脂（二肉豆蔻酰磷脂酰甘油，DMPG）诱导的β-乳球蛋白（β-LG）的构象变化。实验结果表明，β-LG与DMPG的相互作用导致β-LG二级结构元件发生结构重组，同时α-螺旋含量增加，蛋白质三级结构松弛。通过荧光光谱进一步评估了β-LG与DMPG之间的相互作用力。荧光光谱数据表明，蛋白质的构象变化首先由静电相互作用驱动，然后由带负净电荷的蛋白质与带负电荷的磷脂之间的疏水相互作用驱动。