Enzymes catalyzing protein folding and their cellular functions.
Enzymes catalyzing protein folding and their cellular functions.
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催化蛋白质折叠的酶及其细胞功能。
DOI：
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发表时间：
2007
影响因子：
2.8
通讯作者：
N. Nagradova
中科院分区：
文献类型：
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作者：
N. Nagradova
在活细胞中，蛋白质折叠通常不能自发发生，而是需要辅助蛋白-分子伴侣和折叠酶的参与。分子伴侣所采用的机制显着增加蛋白质折叠的有效性，但对该过程的速率没有影响，而折叠酶实际上通过对整个反应的限速步骤施加直接影响来加速蛋白质折叠。已知两种类型的折叠酶，使用不同的作用原理。肽基-脯氨酰顺式/反式异构酶和蛋白质-二硫键异构酶催化需要脯氨酰肽键异构化或二硫键形成和异构化以进行正确折叠的每种蛋白质的折叠。相比之下，一些在细菌细胞周质中工作的折叠酶被专门设计用于帮助底物蛋白的折叠，所述底物蛋白的一级结构不包含用于正确折叠的足够信息。在这篇综述中，我们讨论了这两种类型的折叠酶的催化机制的最新数据，特别关注催化剂如何提供折叠靶蛋白所需的结构信息。两种不同的周质折叠酶所采用的机制的比较分析是用来证实的概念，这是不能独立折叠的蛋白质和特定的催化剂提供必要的空间信息的组合可能是为了实现一些特定的生物学目的。审查还涵盖了参与的肽基脯氨酰顺/反异构酶在不同的细胞功能的问题，突出了这种酶在构象重排折叠的天然蛋白质的作用。
In live cells, protein folding often cannot occur spontaneously, but requires the participation of helper proteins - molecular chaperones and foldases. The mechanisms employed by chaperones markedly increase the effectiveness of protein folding, but have no bearing on the rate of this process, whereas foldases actually accelerate protein folding by exerting a direct influence on the rate-limiting steps of the overall reaction. Two types of foldases are known, using different principles of action. Peptidyl-prolyl cis/trans isomerase and protein-disulfide isomerase catalyze the folding of every protein that needs isomerization of prolyl peptide bonds or formation and isomerization of disulfide bonds for proper folding. By contrast, some foldases operating in the periplasm of bacterial cells are specifically designed to help in the folding of substrate proteins whose primary structure does not contain sufficient information for correct folding. In this review, we discuss recent data on the catalytic mechanisms of both types of foldases, focusing specifically on how a catalyst provides the structural information required for the folding of a target protein. Comparative analysis of the mechanisms employed by two different periplasmic foldases is used to substantiate the notion that combinations of a protein which is unable to fold independently and a specific catalyst delivering the necessary steric information are probably designed to achieve some particular biological purposes. The review also covers the problem of participation of peptidyl-prolyl cis/trans isomerase in different cellular functions, highlighting the role of this enzyme in conformational rearrangements of folded native proteins.