Fig. 1
From: Cysteinyl-tRNA synthetase governs cysteine polysulfidation and mitochondrial bioenergetics
Formation of cysteine persulfide (CysSSH) and CysS–(S) n –H in proteins and their biosynthesis by EcCARS. a Quantitative identification by LC-MS/MS analysis of CysS–(S) n –H formed in recombinant ADH5 after pronase digestion of the HPE-IAM-labeled protein. b Formation of cysteine (CysSH) and CysS–(S) n –H on tRNA (Cys-tRNACysS–(S)n–H) as identified by HPE-IAM labeling LC-MS/MS analysis, which determined the amounts of CysSH and CysS–(S) n –H released from Cys-tRNACys and Cys-tRNACysS–(S)n–H synthesized in the EcCARS enzymatic reaction after their heat or alkaline treatment. The method employed is illustrated in the upper panel. c GAPDH cysteine polysulfides are formed and incorporated into nascent polypeptides synthesized de novo in ribosomes, as identified by PUNCH-PsP (Supplementary Fig. 10; cf. Supplementary Fig. 6). d CysS–(S) n –H formation from cysteine, catalyzed by EcCARS, as dependent on enzyme and substrate (cysteine) concentrations and reaction time (lower panel). Schematic representation of the EcCARS-catalyzed reaction (upper panel). HPE-AM, β-(4-hydroxyphenyl)ethyl acetamide; HPE-IAM, β-(4-hydroxyphenyl)ethyl iodoacetamide. Data a, b are means ± s.d. (n = 3)
