树状聚合物与牛血清白蛋白的复合物。

Complexes of dendrimers with bovine serum albumin.

机构信息

Departement de Chimie-Biologie, Universite du Quebec a Trois-Rivieres, Canada.

出版信息

Biomacromolecules. 2010 Feb 8;11(2):465-72. doi: 10.1021/bm9011979.

DOI:10.1021/bm9011979

PMID:20085247

Abstract

We report the complexation of bovine serum albumin (BSA) with several dendrimers of different compositions mPEG-PAMAM (G3), mPEG-PAMAM (G4), and PAMAM (G4) at physiological conditions using constant protein concentration and various dendrimer contents. FTIR, CD, and fluorescence spectroscopic methods were used to analyze polymer binding mode, the binding constant, and the effects of dendrimer complexation on BSA stability and conformation. Structural analysis showed that dendrimers bind BSA via hydrophilic and hydrophobic interactions with a number of bound polymers (n): 1.30 for mPEG-PAMAM-G3, 1.30 for mPEG-PAMAM-G4, and 1.0 for PAMAM-G4. The polymer-BSA binding constants were K(mPEG-G3) = 5.0 (+/-0.8) x 10(3) M(-1), K(mPEG-G4) = 1.0 (+/-0.3) x 10(4) M(-1), and K(PAMAM-G4) = 1.1 (+/-0.4) x 10(4) M(-1). Dendrimer binding altered BSA conformation with a major reduction of alpha-helix and an increase in random coil and turn structures, indicating a partial protein unfolding.

摘要

我们报告了在生理条件下，使用恒定的蛋白质浓度和不同的树状大分子含量，几种不同组成的树枝状大分子（mPEG-PAMAM（G3）、mPEG-PAMAM（G4）和 PAMAM（G4））与牛血清白蛋白（BSA）的络合。傅里叶变换红外光谱（FTIR）、圆二色光谱（CD）和荧光光谱方法用于分析聚合物结合模式、结合常数，以及树状大分子络合对 BSA 稳定性和构象的影响。结构分析表明，树状大分子通过亲水和疏水相互作用与一定数量的结合聚合物（n）结合 BSA：mPEG-PAMAM-G3 为 1.30，mPEG-PAMAM-G4 为 1.30，PAMAM-G4 为 1.0。聚合物-BSA 结合常数为 K（mPEG-G3）=5.0（+/-0.8）x10(3)M(-1)，K（mPEG-G4）=1.0（+/-0.3）x10(4)M(-1)，K（PAMAM-G4）=1.1（+/-0.4）x10(4)M(-1)。树状大分子的结合改变了 BSA 的构象，主要减少了α-螺旋，增加了无规卷曲和转角结构，表明蛋白质部分展开。