A new deuterated alkylating agent for quantitative proteomics

Weakly basic molecules containing a double bond, such as 2- and 4-vinylpyridine, are able to react and selectively alkylate –SH groups in proteins, thus preventing their re-oxidation to disulphide bridges. In contrast to conventional alkylating agents such as iodoacetamide and non-charged acrylamide derivatives, such molecules achieve 100% alkylation of all –SH residues, even in complex proteins, without reacting with other functional groups. Their use is particularly effective in proteome analysis and more generally for analyzing proteins in which the –SH groups should be blocked. Additionally, the use of vinylpyridines, partially or totally deuterated and thus with a mass difference compared with their non-deuterated counterparts of 4–7 Da, allows studies of induction/repression of protein synthesis (quantitative proteomics)