Protein thermostability. Correlations between calculated macroscopic parameters and growth temperature for closely related thermophilic and mesophilic bacilli.
Protein thermostability. Correlations between calculated macroscopic parameters and growth temperature for closely related thermophilic and mesophilic bacilli.
复制标题
蛋白质的热稳定性。
DOI：
10.1111/j.1399-3011.1981.tb03004.x
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发表时间：
1981
期刊：
影响因子：
--
通讯作者：
F. Wedler
中科院分区：
文献类型：
--
作者：
D. Merkler;G. Farrington;F. Wedler
来自各种密切相关的嗜温和嗜热微生物（特别是芽孢杆菌）的 20 多种酶和蛋白质的氨基酸组成已被用来计算各种宏观参数。这些包括疏水指数 (H phi )、极性与非极性体积之比 (rho)、Arg/(Arg + Lys) 和 (Arg + Lys) 或 (Glx + Asx) 与总氨基酸的比率、H 键合氨基酸百分比、α 螺旋或 β 折叠氨基酸百分比、理论解链温度 (TCalcm)、总体积与总氨基酸比率 (VR) 和 %非极性残基（NPS）。与之前对不同来源的蛋白质进行的类似比较相比，我们发现来自同一属的嗜热与嗜温蛋白质显示出热稳定性与 H phi 增加、rho 减少和 Arg/(Arg + Lys) 增加以及 α 指数和 β 指数增加之间的相关性。 VR、TCalcm、脂肪族指数和 NPS 的相关性较弱，所有这些都源自 H phi 或与之相关。其他计算参数不存在相关性。这些结果与 Argos 等人的最新结果一致。 (1979) [生物化学 18, 5698-5703] 甘油醛-3-P 脱氢酶的序列分析，其中嗜热蛋白显示出多个氨基酸替换，导致内部疏水性增加和外部极性增加。在从嗜温与嗜热杆菌的粗胞质蛋白提取物的氨基酸组成计算的任何参数中均未观察到趋势。
The amino acid composition of more than 20 enzymes and protein from various closely related mesophilic and thermophilic micro-organisms (esp. Bacillus) have been used to calculate a variety of macroscopic parameters. These included the hydrophobic index (H phi ), the ratio of polar to non-polar volumes (rho), the ratios of Arg/(Arg + Lys), and (Arg + Lys) or (Glx + Asx) to total amino acids, % H-bonding amino acids, % alpha-helix- or beta-sheet-forming amino acids, the theoretical melting temperature (TCalcm), the total volume to total amino acid ratio (VR), and the % non-polar residues (NPS). In contrast to previous similar comparisons with proteins from divergent sources, it was found that thermophilic vs mesophilic proteins from the same genus show correlations between thermostability and increased H phi, decreased rho, and increased Arg/(Arg + Lys), as well as increased alpha-index and beta-index. Weaker correlations were seen for VR, TCalcm, aliphatic index, and NPS, all derived from, or related to, H phi. No correlations existed for the other calculated parameters. These results are consistent with recent results of Argos et al. (1979) [Biochemistry 18, 5698-5703] on sequence analyses of glyceraldehyde-3-P dehydrogenases, where thermophilic proteins showed multiple amino acid replacements that caused increased internal hydrophobicity and increased external polarity. No trends were observed in any of the parameters calculated from amino acid compositions for crude cytoplasmic protein extracts from mesophilic vs thermophilic Bacilli.