Klaassen C D, Bracken W M, Dudley R E, Goering P L, Hazelton G A, Hjelle J J
Fundam Appl Toxicol. 1985 Oct;5(5):806-15. doi: 10.1016/0272-0590(85)90164-2.
Endogenous sulfhydryl compounds serve a critical role in maintaining the function and viability of living systems. Glutathione (GSH) is the most abundant of these nonprotein thiols. During the past decade it has been demonstrated that sulfhydryls such as GSH also serve an important role in protecting vital nucleophilic sites in the liver from electrophilic attack by numerous classes of reactive chemicals. Organocompounds such as bromobenzene and acetaminophen which undergo microsomal metabolism yield reactive intermediates that are specifically inactivated by conjugation with sulfhydryls in the form of GSH. Thus, for organocompounds GSH is extremely important in protecting against toxic insults. More recently, other sulfhydryl compounds also have been found to serve a specific but as yet less defined role in protecting biological systems against chemically induced injury. Metals such as cadmium have a high affinity for sulfhydryls and the metal binding protein metallothionein binds cadmium with high affinity. The highly specific association of the metal with this sulfhydryl-enriched protein serves to effectively sequester the reactive cadmium ion. The central role of sulfhydryl equivalents in the detoxication of organo- and metallocompounds is similar; however, the mechanism by which this is achieved is fundamentally different.
内源性巯基化合物在维持生命系统的功能和活力方面发挥着关键作用。谷胱甘肽（GSH）是这些非蛋白质硫醇中含量最丰富的。在过去十年中，已证明诸如GSH之类的巯基在保护肝脏中的重要亲核位点免受多种活性化学物质的亲电攻击方面也发挥着重要作用。诸如溴苯和对乙酰氨基酚之类的有机化合物经过微粒体代谢会产生反应性中间体，这些中间体通过与GSH形式的巯基结合而被特异性灭活。因此，对于有机化合物而言，GSH在防止毒性损伤方面极为重要。最近，还发现其他巯基化合物在保护生物系统免受化学诱导的损伤方面发挥着特定但尚未明确的作用。诸如镉之类的金属对巯基具有很高的亲和力，而金属结合蛋白金属硫蛋白则以高亲和力结合镉。金属与这种富含巯基的蛋白质的高度特异性结合有助于有效螯合反应性镉离子。巯基等价物在有机化合物和金属化合物解毒中的核心作用是相似的；然而，实现这一作用的机制却根本不同。
