Surface-induced conformational changes in lattice model proteins by Monte Carlo simulation.
Surface-induced conformational changes in lattice model proteins by Monte Carlo simulation.
复制标题
通过蒙特卡罗模拟，表面诱导的晶格模型蛋白质构象变化。
DOI：
10.1103/physreve.65.031912
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发表时间：
2002
期刊：
影响因子：
--
通讯作者：
VanTassel,PaulR
中科院分区：
文献类型：
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作者：
Castells,Victoria;Yang,Shaoxiong;VanTassel,PaulR
我们提出了一个27段晶格模型蛋白质吸附在固体表面的热、结构和动态特性的蒙特卡罗模拟。该蛋白由a和B段序列组成，其顺序和拓扑接触能值被选择，以便在没有吸附表面的情况下发生独特的（3x3x3立方）折叠态[EI] Shakhnovich和M. Gutin, Proc. Natl。学会科学。美国90,7195(1993)]。表面由一个位点平面组成，这些位点可以(i)与所有接触的蛋白质片段（一个相等的亲和表面）相互作用，或者（ii）与a型接触片段（一个a亲和表面）相互作用更强。对于这两个表面，我们发现最初折叠的蛋白质的构象变化始于连续过渡到所有片段接触表面的结构。接着是部分再折叠到低能态；这一步骤是连续的，导致等亲和表面完全接触，并被激活，导致A亲和表面明显失去表面接触。我们还观察到，随着温度的升高，等(a)亲和表面的平均表面接触程度减小（增大）。
We present Monte Carlo simulations of thermal, structural, and dynamic properties of a 27-segment lattice model protein adsorbed to a solid surface. The protein consists of a sequence of A and B segments whose order and topological contact energy values are chosen so that a unique (3× 3× 3 cubic) folded state occurs in the absence of an adsorbing surface [EI Shakhnovich and M. Gutin, Proc. Natl. Acad. Sci. USA 90, 7195 (1993)]. The surface consists of a plane of sites that interact either (i) equally with all contacting protein segments (an equal affinity surface) or (ii) more strongly with type A contacting segments (an A affinity surface). For both surfaces, we find the conformational change of an initially folded protein to begin with a continuous transition to a structure where all segments contact the surface. This is followed by a partial refolding to a low energy state; this step is continuous and results in full surface contact for the equal affinity surface and is activated and results in significant loss of surface contact for the A affinity surface. We also observe a lesser (greater) degree of average surface contact in the equal (A) affinity surface with an increase in temperature.