Posttranslational nitrosation

The oxidative addition of NO to a thiol, termed S-nitrosation, is a posttranslational modification that can modulate protein function. With high concentrations of NO, this modification can alter protein function indiscriminately however, only a limited number of proteins are S-nitrosated in vivo (8). This selectivity of nitrosothiol formation suggests that a mechanism of regulation of SNO formation and/or decay exists however, the details of this regulation are unknown. 

Fig. 1 Posttranslational redox modificatitnis to amino acids in proteins. Many amino acids can undergo various posttranslatiraial redox modifications in the presence of NAPQI, oxidative stress, and nitrosative stress. Thiols in cysteine can undergo covalent binding, mixed disulfide formation, nitrosylation, and become oxidized to sulfenic, sulfinic, and sulfonic acids. Tyrosine can become nitrated by peroxynitrate, and methionine can be oxidized by ROS to methionine sulfoxide. Not shown are many other oxidatirais that can occur to other amino acids such as proline, histidine, etc.

Handy, D.E., and Loscalzo, J. (2006). Nitric oxide and posttranslational modification of the vascular proteome S-nitrosation of reactive thiols. Arterioscler. Thromb. Vase. Biol. 26, 1207-1214. 

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