title: Characterization by tandem mass spectrometry of stable cysteine sulfenic acid in a cysteine switch peptide of matrix metalloproteinases.
abstract: Cysteine sulfenic acid (Cys-SOH) is an elusive intermediate in reactive oxygen species-induced oxidation reactions of many proteins such as peroxiredoxins and tyrosine phosphatases. Cys-SOH is proposed to play a vital role in catalytic and signaling functions. The formation of cysteine sulfinic acid (Cys-SO(2)H) and cysteine sulfonic acid (Cys-SO(3)H) has been implicated in the activation of matrix metalloproteinase-7 (MMP-7) and oxidation of thiol to cysteine sulfinic acid has been associated with the autolytic cleavage of MMP-7. We have examined the formation of cysteine sulfenic acid in a synthetic peptide PRCGVPDVA, which is a cysteine switch domain of MMP-7 and other matrix metalloproteases. We have prepared the cysteine sulfenic acid containing peptide, PRC(SOH)GVPDVA, by reaction with hydroxyl radicals generated by the Fenton reaction (Fe(+2)/H(2)O(2)). We characterized this modified peptide by tandem mass spectrometry and accurate mass measurement experiments. In addition, we used 7-chloro-4-nitrobenzo-2-oxa-1,3-diazol (NBD-Cl) reagent to form an adduct with PRC(SOH)GVPDVA to provide additional evidence for the viability of PRC(SOH)GVPDVA in solution. We also characterized an intramolecular cysteine sulfinamide cross-link product PRC[S(O)N]GVPDVA based on tandem mass spectrometry and accurate mass measurement experiments. These results contribute to the understanding of a proteolytic cleavage mechanism that is traditionally associated with MMP activation.
authors.affiliation: Skirball Institute of Biomolecular Medicine and Department of Pharmacology, New York University School of Medicine, New York, New York 10016, USA.
authors.forename: Vivekananda
authors.initials: V
authors.lastname: Shetty
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Spellman
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Neubert
mesh_terms: D000595:Amino Acid Sequence; D002384:Catalysis; D003545:Cysteine / Q000031:analogs & derivatives* / Q000032:analysis; D020782:Matrix Metalloproteinases / Q000378:metabolism*; D010084:Oxidation-Reduction; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry; D013434:Sulfenic Acids / Q000032:analysis*; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D010455:Peptides; D013434:Sulfenic Acids; D020782:Matrix Metalloproteinases; C100870:cysteinesulfenic acid; D003545:Cysteine; C013461:cysteine sulfinic acid