Structural and thermodynamic encoding in the sequence of rat microsomal cytochrome b(5).
Structural and thermodynamic encoding in the sequence of rat microsomal cytochrome b(5).
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大鼠微粒体细胞色素 b(5) 序列的结构和热力学编码。
DOI：
10.1002/bip.20892
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发表时间：
2008
期刊：
影响因子：
2.9
通讯作者：
Pond,MatthewP
中科院分区：
文献类型：
--
作者：
Lecomte,JulietteTJ;Mukhopadhyay,Kunal;Pond,MatthewP
大鼠微粒体细胞色素b 5的水溶性结构域是一种方便的蛋白质，可以用来考察氨基酸序列与热力学性质之间的联系。在缺乏单一血红素辅因子的情况下，cytochromeb 5含有一段约30个残基的部分折叠。这个区域被认为是容易通过分析这种内在特征的一级结构的程序来紊乱的。对细胞色素的折叠核心（I12 A）、仅在与血红素基团接触时再折叠的部分（N57 P）以及两者（F35 H/H39 A/L46 Y）进行氨基酸置换。尽管测量血红素结合物种的热力学量存在困难，但有可能合理化这两种类型替代的能量后果，并测试一个简单的脱辅基蛋白和全蛋白稳定性方程。此外，在Tm（在热转变的中点处的温度）的变化和由化学变性确定的热力学稳定性的变化之间的现象学关系被观察到，可以被用来扩展不完整的全蛋白稳定性数据的解释。通过核磁共振光谱法获得结构信息，以进行原子水平的效应分析。© 2007 Wiley Periodicals，Inc. Biopolymers 89：428-442，2008。这篇文章最初作为公认的预印本在线发表。“在线发布”日期对应于预印本。您可以通过向Biopolymers编辑部发送电子邮件（biopolymers@wiley.com）索取预印本的副本
The water‐soluble domain of rat microsomal cytochromeb5is a convenient protein with which to inspect the connection between amino acid sequence and thermodynamic properties. In the absence of its single heme cofactor, cytochromeb5contains a partially folded stretch of ˜30 residues. This region is recognized as prone to disorder by programs that analyze primary structures for such intrinsic features. The cytochrome was subjected to amino acid replacements in the folded core (I12A), in the portion that refolds only when in contact with the heme group (N57P), and in both (F35H/H39A/L46Y). Despite the difficulties associated with measuring thermodynamic quantities for the heme‐bound species, it was possible to rationalize the energetic consequences of both types of replacements and test a simple equation relating apoprotein and holoprotein stability. In addition, a phenomenological relationship between the change inTm(the temperature at the midpoint of the thermal transition) and the change in thermodynamic stability determined by chemical denaturation was observed that could be used to extend the interpretation of incomplete holoprotein stability data. Structural information was obtained by nuclear magnetic resonance spectroscopy toward an atomic‐level analysis of the effects. © 2007 Wiley Periodicals, Inc. Biopolymers 89: 428–442, 2008.This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com