Conformational stability of collagen relies on a stereoelectronic effect
Conformational stability of collagen relies on a stereoelectronic effect
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DOI：
10.1021/ja005542v
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发表时间：
2001-01-31
影响因子：
15
通讯作者：
Raines, RT
中科院分区：
文献类型：
--
作者：
Bretscher, LE;Jenkins, CL;Raines, RT
多肽链可以有多种构象。然而，它的氨基酸残基序列将折叠引导到特定的天然状态。与折叠相关的构象熵的损失使原生态不稳定。这种不稳定性被疏水效应、氢键、其他非共价相互作用和二硫化物键所克服。我们已经确定了另一种能促进蛋白质构象稳定性的力。有机分子的结构和反应性取决于其成键或非成键电子对的立体化学性质。这种立体电子效应是由电子对与相邻极性键（CX，其中X为N或O）的反键σ*混合而产生的，赋予核酸和碳水化合物构象稳定性。例如，由2 '氧引起的多重间扭式效应（XCCX）将RNA、RNA和RNA、DNA双链与DNA、DNA双链区分开来。5 .异构体效应（XCX）增强了糖苷R异构体的稳定性。在这里，我们首次证明了立体电子效应对蛋白质的构象稳定性至关重要。
A polypeptide chain can adopt many conformations. Yet, the sequence of its amino acid residues directs folding to a particular native state. 1 The loss of conformational entropy associated with folding destabilizes the native state. This destabilization is overcome by the hydrophobic effect, hydrogen bonds, other noncovalent interactions, and disulfide bonds. 2 We have identified another force that can contribute to the conformational stability of a protein.The structure and reactivity of an organic molecule can rely on the stereochemistry of its electron pairs, bonded or nonbonded. 3 Such stereoelectronic effects, which arise from the mixing of an electron pair with the antibonding σ* of an adjacent polar bond (CX, where X) N or O), endow nucleic acids and carbohydrates with conformational stability. 4 For example, the multiple gauche effects (XCCX) arising from a 2′ oxygen distinguish RNA ‚RNA and RNA ‚DNA duplexes from DNA ‚DNA duplexes. 5 The anomeric effect (XCX) enhances the stability of the R anomer of glycosides. 6 Here, we demonstrate for the first time that a stereoelectronic effect is critical for the conformational stability of a protein.