Factors enhancing protein thermostability
Factors enhancing protein thermostability
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DOI：
10.1093/protein/13.3.179
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发表时间：
2000-03-01
期刊：
影响因子：
--
通讯作者：
Nussinov, R
中科院分区：
文献类型：
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作者：
Kumar, S;Tsai, CJ;Nussinov, R
已经提出了几种序列和结构因素有助于提高嗜热蛋白的稳定性。在这里，我们对 18 个非冗余嗜热和嗜温蛋白质家族的代表的结构和序列参数进行了统计检查。我们的目的是寻找各个家族中嗜热和嗜温蛋白质之间的系统差异。我们观察到，嗜热和嗜温蛋白质都具有相似的疏水性、致密性、寡聚状态、对表面积、主链和侧链氢键的极性和非极性贡献。插入/缺失和脯氨酸取代在家族的嗜热和嗜温成员之间没有表现出一致的趋势。另一方面，大多数嗜热蛋白质中盐桥和侧链-侧链氢键增加。此外，嗜热-中温同源蛋白对的序列比较表明，Arg和Tyr在嗜热蛋白中出现的频率明显更高，而Cys和Ser在嗜热蛋白中出现的频率较低，嗜热蛋白在α螺旋构象中的残基比例更大，并且它们在α螺旋中比嗜温蛋白更大程度地避免Pro，这些结果表明耐热蛋白采用双重策略来承受高温。我们的目的是探索有助于嗜热菌蛋白质在熔解温度（T-m）方面稳定性的因素，熔解温度是热稳定性的最佳描述。不幸的是，T-m 值仅适用于我们高分辨率数据集中的少数蛋白质，目前，这限制了我们以有意义的方式检查相关性的能力。
Several sequence and structural factors have been proposed to contribute toward greater stability of thermophilic proteins. Here we present a statistical examination of structural and sequence parameters in representatives of 18 nonredundant families of thermophilic and mesophilic proteins. Our aim was to look for systematic differences among thermophilic and mesophilic proteins across the families. We observe that both thermophilic and mesophilic proteins have similar hydrophobicities, compactness, oligomeric states, polar and non-polar contribution to surface areas, main-chain and side-chain hydrogen bonds. Insertions/deletions and proline substitutions do not show consistent trends between the thermophilic and mesophilic members of the families. On the other hand, salt bridges and side chain-side chain hydrogen bonds increase in the majority of the thermophilic proteins. Additionally, comparisons of the sequences of the thermophile-mesophile homologous protein pairs indicate that Arg and Tyr are significantly more frequent, while Cys and Ser are less frequent in thermophilic proteins, Thermophiles both have a larger fraction of their residues in the alpha-helical conformation, and they avoid Pro in their alpha-helices to a greater extent than the mesophiles, These results indicate that thermostable proteins adapt dual strategies to withstand high temperatures. Our intention has been to explore factors contributing to the stability of proteins from thermophiles with respect to the melting temperatures (T-m), the best descriptor of thermal stability. Unfortunately, T-m values are available only for a few proteins in our high resolution dataset, Currently, this limits our ability to examine correlations in a meaningful way.