疏水蛋白在云母表面的吸附  

Adsorption Behavior of Hydrophobin Proteins on Surface of Mica

作　　者：何佳[1] 冯喜增 邵学广[1,2] 蔡文生[1] 

机构地区：[1]天津化学化工协同创新中心 南开大学化学学院分析科学研究中心 [2]药物化学生物学国家重点实验室 [3]生命科学学院,天津300071

出　　处：《高等学校化学学报》2015年第1期110-115,共6页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金(批准号:21373117)资助~~

摘　　要：采用分子动力学模拟方法研究了疏水蛋白(HFBI)在亲水云母表面的吸附过程.通过6组平行的分子动力学模拟得到了2种不同的稳定吸附结构,即通过N端和通过亲水的α螺旋与表面吸附,得到了5种吸附残基.进一步用自适应偏置力方法计算了所有吸附残基与表面的结合自由能.结果表明,残基Lys是吸附过程的关键残基,即当HFBI通过含有Lys残基的α螺旋与云母表面作用时,其吸附构象最稳定.静电作用是吸附过程的主要驱动力.在该吸附结构中,HFBI的疏水面暴露在溶液中,有效降低了云母表面的润湿性.Atomistic molecular dynamics（ MD） simulations were conducted to elucidate the adsorption beha- vior of hydrophobin protein（ HFBI） on the hydrophilic mica surface. Six independent simulations starting from three representative initial orientations of HFBI toward the surface were performed. The adsorbed patches are clustered into two classes, namely theα-helix and the N-terminal part. The main secon-dary structures of pro- tein were preserved in the entire course of adsorption due to four disulfide bonds. Furthermore, binding free energies of five different adsorbed residues were calculated employing the adaptive biasing force method. The results showed that Lys was the key residue for the adsorption. It can be deduced that the adsorption of HFBI via the α-helix part consisting of Gln36, Asn37, Lys50, and Thr51 is most energetically favored. Electrostatic interactions constitute the main driving forces responsible for the adsorption of HFBI on the mica surface. In the most stable adsorbed structure, the hydrophobic patch was exposed in the aqueous media, leading to the reduction of the wettability of mica.

关 键 词：疏水蛋白 云母 分子动力学模拟 自由能计算 吸附构象 自适应偏置力方法 

分 类 号：O641[理学—物理化学]