Reactivity of C-terminal cysteines with HNO

Gizem Keceli, John P. Toscano

Research output: Contribution to journalArticlepeer-review


Nitroxyl (HNO), a potential heart failure therapeutic, is known to target cysteine residues to form sulfinamides and/or disulfides. Because HNO-derived modifications may depend on their local environment, we have investigated the reactivity of HNO with cysteine derivatives and C-terminal cysteine-containing peptides at physiological pH and temperature. Our findings indicate that the nature of HNO-derived modifications of C-terminal cysteines is affected by the C-terminal carboxylate. Apart from the lack of sulfinamide formation, these studies have revealed the presence of new products, a sulfohydroxamic acid derivative (RS(O)2NHOH) and a thiosulfonate (RS(O)2SR), presumably produced under our experimental conditions via the intermediacy of a cyclic structure that is hydrolyzed to give a sulfenic acid (RSOH). Moreover, these modifications are formed independent of oxygen.

Original languageEnglish (US)
Pages (from-to)3689-3698
Number of pages10
Issue number22
StatePublished - Jun 10 2014

ASJC Scopus subject areas

  • Biochemistry


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