谷胱甘肽硫转移酶结构与功能研究进展

Structure and Catalytic Mechanism of the Glutathione Transferases

谷胱甘肽转硫酶(G lutath ione S-transferases,简称GSTs,EC2.5.1.18)是广泛分布于哺乳动物、植物、鸟类、昆虫、寄生虫及微生物体内的一组多功能同工酶,其主要功能是催化某些内源性或外来有害物质的亲电子基团与还原型谷胱甘肽的巯基偶联,增加其疏水性使其易于穿越细胞膜,分解后排出体外,从而达到解毒的目的.着重介绍了近年来谷胱甘肽硫转移酶结构与功能研究的进展,详细描述并比较了多种同工酶的三级结构、生化功能、催化机制以及底物特异性,同时对GSTs种类之间结构与功能的进化做了较深入探讨.

The glutathione S-transferases （GST） are a supergene family of dimeric enzymes that catalyse the conjugation of glutathione （GSH） to a variety of electrophiles, including arene oxides, unsaturated carbonyls, organic halides and other substrates. Their importance is suggested by the finding that GST enzymes are expressed in probably all life forms. Since the first half of last decade scientists have been focusing on the elucidation of the three-dimensional structures of several cytosolic isoenzymes. The structural information has had a profound impact on our understanding of the catalytic mechanisms of the glutathione transferases, the evolution of the protein fold, and the molecular basis for their participation in the detoxification of endogenous and xenobiotic electrophiles. The purpose of this review is to illustrate how the knowledge of the three-dimensional structures has influenced current ideas on the evolution and function of these enzymes in biological systems.