Protein engineering of cytochrome c by semisynthesis: substitutions at glutamic acid 66.
Protein engineering of cytochrome c by semisynthesis: substitutions at glutamic acid 66.
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通过半合成进行细胞色素 c 的蛋白质工程：谷氨酸 66 处的取代。
DOI：
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发表时间：
1986
期刊：
影响因子：
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通讯作者：
B. Corthésy
中科院分区：
文献类型：
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作者：
C. Wallace;B. Corthésy
我们已经使用蛋白质半合成，以制备四个类似物的马细胞色素c，其中谷氨酸残基在位置66已被删除，并取代正缬氨酸，谷氨酰胺，赖氨酸，并作为方法控制，谷氨酸。这个残基在线粒体细胞色素c中是相当保守的，并且形成了所有细胞色素c中出现的酸性残基簇的一部分，但是其功能是模糊的。类似物的物理和生物化学性质的比较研究现在已经揭示了Glu66在蛋白质中的两个特定作用。它有助于显着稳定的蛋白质的活性构象，可能是通过盐桥形成，它似乎参与了氧化还原状态依赖的ATP结合位点的细胞色素c。我们的研究结果也支持两个一般性的看法，表面带电的残留物在细胞色素c中的作用，即它们的处置影响氧化还原电位，通过静电场感觉在氧化还原中心，和动力学的电子转移，通过它们产生的偶极矩。
We have used protein semisynthesis to prepare four analogues of horse cytochrome c, in which the glutamic acid residue at position 66 has been removed and replaced by norvaline, glutamine, lysine and, as a methodological control, glutamic acid. This residue is quite strongly conserved in mitochondrial cytochrome c, and forms part of a cluster of acidic residues that occurs in all cytochromes c but whose function is obscure. Comparative studies of the physical and biochemical properties of the analogues have now disclosed two specific roles for Glu66 in the protein. It contributes significantly to the stabilization of the active conformation of the protein, probably by salt bridge formation, and it appears to participate in the redox-state-dependent ATP-binding site of cytochrome c. Our results also support two general views of the role of surface charged residues in cytochrome c, namely that their disposition influences both redox potential, through the electrostatic field felt at the redox centre, and the kinetics of electron transfer, through the dipole moment they generate.