STRUCTURAL BASIS OF AMINO-ACID ALPHA-HELIX PROPENSITY
STRUCTURAL BASIS OF AMINO-ACID ALPHA-HELIX PROPENSITY
复制标题
DOI：
10.1126/science.8503008
复制
发表时间：
1993-06-11
期刊：
影响因子：
56.9
通讯作者：
MATTHEWS, BW
中科院分区：
文献类型：
--
作者：
BLABER, M;ZHANG, XJ;MATTHEWS, BW
氨基酸在蛋白质中形成 α 螺旋的倾向是通过 T4 溶菌酶中 44 和 131 位的多个氨基酸取代来确定的。这些位置是 α 螺旋内的溶剂暴露位点，分别包含残基 39 至 50 和 126 至 134。除了可能涉及盐桥的两个酸性取代外，这两个位点的稳定性变化非常一致。稳定性值也与在一些模型肽中观察到的相应氨基酸取代的稳定性值一致。因此，源自模型肽的螺旋倾向值可适用于蛋白质。在 20 种天然存在的氨基酸中，脯氨酸、甘氨酸和丙氨酸均具有独特的结构特征，这有助于解释它们的低或高螺旋倾向。对于其余 17 个氨基酸，埋藏在螺旋侧面的侧链疏水表面似乎对螺旋倾向有很大贡献。
The propensity of an amino acid to form an alpha helix in a protein was determined by multiple amino substitutions at positions 44 and 131 in T4 lysozyme. These positions are solvent-exposed sites within the alpha helices that comprise, respectively, residues 39 to 50 and 126 to 134. Except for two acidic substitutions that may be involved in salt bridges, the changes in stability at the two sites agree well. The stability values also agree with those observed for corresponding amino acid substitutions in some model peptides. Thus, helix propensity values derived from model peptides can be applicable to proteins. Among the 20 naturally occurring amino acids, proline, glycine, and alanine each have a structurally unique feature that helps to explain their low or high helix propensities. For the remaining 17 amino acids, it appears that the side chain hydrophobic surface buried against the side of the helix contributes substantially to a helix propensity.