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).