Hendrick J P, Hartl F U
Cellular Biochemistry and Biophysics Program, Memorial Sloan-Kettering Cancer Center, New York, New York 10021, USA.
FASEB J. 1995 Dec;9(15):1559-69. doi: 10.1096/fasebj.9.15.8529835.
Folding of newly synthesized polypeptides in the crowded cellular environment requires the assistance of so-called molecular chaperone proteins. Chaperones of the Hsp70 class and their partner proteins interact with nascent polypeptide chains on ribosomes and prevent their premature (mis)folding at least until a domain capable of forming a stable structure is synthesized. For many proteins, completion of folding requires the subsequent interaction with one of the large oligomeric ring-shaped proteins of the chaperonin family, which is composed of the GroEL-like proteins in eubacteria, mitochondria, and chloroplasts, and the TRiC family in eukaryotic cytosol and archaea. These proteins bind partially folded polypeptide in their central cavity and promote folding by ATP-dependent cycles of release and rebinding. In these reactions, molecular chaperones interact predominantly with the hydrophobic surfaces exposed by nonnative polypeptides, thereby preventing incorrect folding and aggregation.
在拥挤的细胞环境中，新合成的多肽折叠需要所谓分子伴侣蛋白的协助。Hsp70类分子伴侣及其伴侣蛋白与核糖体上的新生多肽链相互作用，至少在能够形成稳定结构的结构域合成之前，防止它们过早（错误）折叠。对于许多蛋白质来说，折叠的完成需要随后与伴侣蛋白家族的一种大型寡聚环状蛋白相互作用，该家族由真细菌、线粒体和叶绿体中的GroEL样蛋白以及真核细胞质和古细菌中的TRiC家族组成。这些蛋白在其中心腔中结合部分折叠的多肽，并通过依赖ATP的释放和重新结合循环促进折叠。在这些反应中，分子伴侣主要与非天然多肽暴露的疏水表面相互作用，从而防止错误折叠和聚集。
