Biomaterial Database

Reactivity of C-terminal cysteines with HNO. 2014

Gizem Keceli, and John P Toscano

Department of Chemistry, Johns Hopkins University , Baltimore, Maryland 21218, United States.

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.

UI	MeSH Term	Description	Entries
D007097	Imines	Organic compounds containing a carbon-nitrogen double bond where a NITROGEN atom can be attached to HYDROGEN or an alkyl or aryl group.	Imine
D009589	Nitrogen Oxides	Inorganic oxides that contain nitrogen.	Nitrogen Oxide,Oxide, Nitrogen,Oxides, Nitrogen
D003545	Cysteine	A thiol-containing non-essential amino acid that is oxidized to form CYSTINE.	Cysteine Hydrochloride,Half-Cystine,L-Cysteine,Zinc Cysteinate,Half Cystine,L Cysteine
D006868	Hydrolysis	The process of cleaving a chemical compound by the addition of a molecule of water.
D013434	Sulfenic Acids	Oxy acids of sulfur with the general formula RSOH, where R is an alkyl or aryl group such as CH3. They are often encountered as esters and halides. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Sulfenic Acid,Acid, Sulfenic,Acids, Sulfenic
D013438	Sulfhydryl Compounds	Compounds containing the -SH radical.	Mercaptan,Mercapto Compounds,Sulfhydryl Compound,Thiol,Thiols,Mercaptans,Compound, Sulfhydryl,Compounds, Mercapto,Compounds, Sulfhydryl
D013452	Sulfonium Compounds	Sulfur compounds in which the sulfur atom is attached to three organic radicals and an electronegative element or radical.	Sulfine Compounds,Compounds, Sulfine,Compounds, Sulfonium
D021241	Spectrometry, Mass, Electrospray Ionization	A mass spectrometry technique used for analysis of nonvolatile compounds such as proteins and macromolecules. The technique involves preparing electrically charged droplets from analyte molecules dissolved in solvent. The electrically charged droplets enter a vacuum chamber where the solvent is evaporated. Evaporation of solvent reduces the droplet size, thereby increasing the coulombic repulsion within the droplet. As the charged droplets get smaller, the excess charge within them causes them to disintegrate and release analyte molecules. The volatilized analyte molecules are then analyzed by mass spectrometry.	ESI Mass Spectrometry,Electrospray Ionization Mass Spectrometry,Mass Spectrometry, ESI,Spectrometry, ESI Mass