Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States.
Kodikos Laboratories, Institut Cochin, Paris 75014, France.
Biochemistry. 2022 Jun 7;61(11):952-955. doi: 10.1021/acs.biochem.2c00020. Epub 2022 May 18.
In this paper, we describe the biochemical reconstitution of a cysteine salvage pathway and the biochemical characterization of each of the five enzymes involved. The salvage begins with amine acetylation of -alkylcysteine, followed by thioether oxidation. The C-S bond of the resulting sulfoxide is cleaved using a new flavoenzyme catalytic motif to give -acetylcysteine sulfenic acid. This is then reduced to the thiol and deacetylated to complete the salvage pathway. We propose that this pathway is important in the catabolism of alkylated cysteine generated by proteolysis of alkylated glutathione formed in the detoxification of a wide range of electrophiles.
本文描述了半胱氨酸补救途径的生化重建以及涉及的五种酶的生化特性。补救途径从 - 烷化半胱氨酸的胺乙酰化开始，随后进行硫醚氧化。所得亚砜的 C-S 键被一种新的黄素酶催化模体裂解，生成 - 乙酰半胱氨酸亚磺酸。然后将其还原为硫醇并脱乙酰化，以完成补救途径。我们提出该途径在由广泛的亲电试剂解毒形成的烷基化谷胱甘肽的蛋白水解产生的烷基化半胱氨酸的分解代谢中很重要。
