Chapter 13: The Posttranslational Cysteinyl Proteome

There are seven common posttranslational modifications of cysteine residues in human proteomes that have differing stability and different modes of enzymatic reversal. Lipidation of cysteine residues can occur ether by S-acylation from long-chain acyl–CoAs or by S-alkylation by C₁₅ and C₂₀ prenyl diphosphates. The remaining five modifications are oxidative, the leading one being cystine disulfide bond formation, notably during transit through the secretory pathway of cells. The oxidative reactions also include cysteine persulfide formation, oxidation to formylglycine residues in sulfatases, sulfenic acid formation (often as intermediates in disulfide bond construction) and S-nitrosylation. The S-prenylations and S-oxygenations to formylglycine residues are the two irreversible modifications.