L-cysteine sulfenic acid (2R)-2-amino-3-(hydroxysulfanyl)propanoic acid (2R)-2-amino-3-(oxido-lambda(4)-sulfanyl)propanoic acid [tautomer] 119.00409698486328125 119.1399993896484375 15.994915008544921875 16.0 2-amino-2-carboxyethanesulfenic acid 2-amino-3-sulfinylpropanoic acid [tautomer] 3-sulfenoalanine A protein modification that effectively monooxygenates an L-cysteine residue to L-cysteine sulfenic acid. ACT_SITE Cysteine sulfenic acid (-SOH) intermediate C C 0 H 0 N 0 O 1 S 0 C 3 H 5 N 1 O 2 S 1 CysOH From DeltaMass: Average Mass: 16 Average Mass Change:16 Notes:Green et al. in J. B. C. 270, 18209-18211 (1995) quote Kim and Raines in Eur. J. Biochem. 224, 109-114 (1994). Kim and Raines using ESI-MS and sulfhydryl group titration found that bovine seminal ribonuclease contains a single oxidized sulfhydryl group, which cannot participate in a disulfide bond. This form of cysteine is called sulfenic acid (-SOH). L-cysteine sulfenic acid MOD:00210 MOD_RES Cysteine sulfenic acid (-SOH) Oxidation PSI-MOD S-hydroxycysteine S-oxocysteine [tautomer] S-oxycysteine [tautomer] Sulfenic Acid (from Cysteine) Unimod:35 cysteine S-oxide [tautomer] cysteine sulfoxide [tautomer] cysteine sulphenic acid mod193 natural uniprot.ptm:PTM-0107 sulfur oxygenated L-cysteine sulfur monooxygenated residue