Parray Zahoor Ahmad, Shahid Mohammad, Islam Asimul
Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, New Delhi 110025, India.
Department of Chemistry, Indian Institute of Technology Delhi, IIT Campus, Hauz Khas, New Delhi 110016, India.
Polymers (Basel). 2022 Apr 11;14(8):1539. doi: 10.3390/polym14081539.
Proteins are indispensable to cellular communication and metabolism. The structure on which cells and tissues are developed is deciphered from proteins. To perform functions, proteins fold into a three-dimensional structural design, which is specific and fundamentally determined by their characteristic sequence of amino acids. Few of them have structural versatility, allowing them to adapt their shape to the task at hand. The intermediate states appear momentarily, while protein folds from denatured (D) ⇔ native (N), which plays significant roles in cellular functions. Prolific effort needs to be taken in characterizing these intermediate species if detected during the folding process. Protein folds into its native structure through definite pathways, which involve a limited number of transitory intermediates. Intermediates may be essential in protein folding pathways and assembly in some cases, as well as misfolding and aggregation folding pathways. These intermediate states help to understand the machinery of proper folding in proteins. In this review article, we highlight the various intermediate states observed and characterized so far under in vitro conditions. Moreover, the role and significance of intermediates in regulating the biological function of cells are discussed clearly.
蛋白质对于细胞通讯和新陈代谢不可或缺。细胞和组织发育所依赖的结构是由蛋白质解析而来的。为了执行功能，蛋白质折叠成三维结构设计，这种结构是特定的，并且从根本上由其独特的氨基酸序列决定。它们中很少有具有结构通用性的，能够使其形状适应手头的任务。当蛋白质从变性（D）⇌天然（N）状态折叠时，中间状态会瞬间出现，这在细胞功能中起着重要作用。如果在折叠过程中检测到这些中间物种，就需要付出大量努力来对其进行表征。蛋白质通过明确的途径折叠成其天然结构，这些途径涉及数量有限的瞬时中间体。在某些情况下，中间体可能在蛋白质折叠途径和组装中至关重要，在错误折叠和聚集折叠途径中也是如此。这些中间状态有助于理解蛋白质正确折叠的机制。在这篇综述文章中，我们重点介绍了迄今为止在体外条件下观察和表征的各种中间状态。此外，还清晰地讨论了中间体在调节细胞生物学功能中的作用和意义。
