Design of improved protein inhibitors of HIV-1 cell entry: Optimization of electrostatic interactions at the binding interface
Design of improved protein inhibitors of HIV-1 cell entry: Optimization of electrostatic interactions at the binding interface
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DOI：
10.1002/prot.20540
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发表时间：
2005-09-01
影响因子：
2.9
通讯作者：
Tidor, B
中科院分区：
文献类型：
--
作者：
Green, DF;Tidor, B
连续体静电方法是分析和设计生物分子复合物的有力工具，其方法允许详细分析静电对结合亲和力的贡献和计算静电最佳配体的性质的程序。我们已经将这些方法应用于设计改进的HIV-1细胞进入抑制剂。HIV感染细胞需要病毒-细胞膜融合，这一事件部分由病毒膜糖蛋白gp 41的大规模构象变化驱动。这种转化涉及从三个gp 41链的C-末端区域对预形成的三聚体卷曲螺旋的螺旋对接;抑制膜融合的几种蛋白质构建体通过结合到分离的C-末端螺旋并阻断融合结构的形成而起作用。使用HIV-1 gp 41胞外域核心的X-射线晶体结构作为结构模型，对一种这样的抑制剂（5-Hexylamine）与C-末端螺旋结合的静电贡献进行了详细分析，并鉴定了5-Hexylamine上对结合（有利和不利）有实质性贡献的几个残基。静电亲和力优化方法应用于5-Heptane的侧链，结果表明，如果静电对结合自由能的贡献被优化，则结合亲和力可能得到显著改善。几个突变访问的实验方法建议，计算的结合亲和力的改善多达500倍和更大。
Continuum electrostatic methods are a powerful tool for the analysis and design of biomolecular complexes, with methodologies that allow for the detailed analysis of the electrostatic contributions to binding affinities and procedures for computing the properties of electrostatically optimal ligands. We have applied these methods to the design of improved inhibitors of HIV-1 cell entry. HIV infection of a cell requires viral-cell membrane fusion, an event partially driven by a large-scale conformational change in the viral membrane glycoprotein gp41. This transformation involves the docking of a helix from the C-terminal region of three gp41 chains against a pre-formed trimeric-coiled coil; several protein constructs that inhibit membrane fusion act by binding to an isolated C-terminal helix and blocking the formation of the fusogenic structure. A detailed analysis of the electrostatic contributions to the binding of one such inhibitor (5-Helix) to a C-terminal helix was performed using the X-ray crystal structure of the core of the HIV-1 gp41 ectodomain as a structural model, and several residues on 5-Helix that make substantial contributions to binding, both favorable and unfavorable, were identified. An electrostatic affinity optimization methodology was applied to the side chains of 5-Helix, with the results showing that significant improvements in binding affinity are possible if the electrostatic contributions to the binding free energy are optimized. Several mutations accessible by experimental methods are suggested, with calculated improvements in binding affinity of as much as 500-fold and greater.