Querol E, Perez-Pons J A, Mozo-Villarias A
Institut de Biologia Fonamental, Universitat Autònoma de Barcelona, Bellaterra, Spain.
Protein Eng. 1996 Mar;9(3):265-71. doi: 10.1093/protein/9.3.265.
The thermal stability of proteins was studied, 195 single amino acid residue replacements reported elsewhere being analysed for several protein conformational characteristics: type of residue replacement; conservative versus nonconservative substitution; replacement being in a homologous stretch of amino acid residues; change in hydrogen bond, van der Waals and secondary structure propensities; solvent-accessible versus inaccessible replacement; type of secondary structure involved in the substitution; the physico-chemical characteristics to which the thermostability enhancement can be attributed; and the relationship of the replacement site to the folding intermediates of the protein, when known. From the above analyses, some general rules arise which suggest where amino acid substitutions can be made to enhance protein thermostability: substitutions are conservative according to the Dayhoff matrix; mainly occur on conserved stretches of residues; preferentially occur on solvent-accessible residues; maintain or enhance the secondary structure propensity upon substitution; contribute to neutralize the dipole moment of the caps of helices and strands; and tend to increase the number of potential hydrogen bonding or van der Waals contacts or improve hydrophobic packing.
对蛋白质的热稳定性进行了研究，分析了其他地方报道的195个单氨基酸残基替换的几种蛋白质构象特征：残基替换类型；保守替换与非保守替换；替换是否发生在氨基酸残基的同源序列中；氢键、范德华力和二级结构倾向的变化；溶剂可及与不可及的替换；替换所涉及的二级结构类型；可归因于热稳定性增强的物理化学特征；以及当已知时，替换位点与蛋白质折叠中间体的关系。从上述分析中得出了一些一般规则，这些规则表明了可以进行氨基酸替换以提高蛋白质热稳定性的位置：根据Dayhoff矩阵，替换是保守的；主要发生在保守的残基序列上；优先发生在溶剂可及的残基上；替换后维持或增强二级结构倾向；有助于中和螺旋和链的帽的偶极矩；并且倾向于增加潜在的氢键或范德华接触的数量或改善疏水堆积。
