| 摘要 |
The invention provides reagents and kits for introducing a fixed charge to the side-chain of methionine, and peptides and proteins containing methionine, for selective identification by tandem mass spectrometry. The reagents are based on substituted acetophenones according to the following formula: The reagents of the present invention may also be used for differential quantitation of peptide concentrations between two different samples, by incorporation of stable isotope labels to the reagent, to yield a 'light' form (containing only natural isotopes), and a 'heavy' form by incorporating stable isotope labels into the substituent. These reagents give a mass difference of at least 8 Daltons and up to 13 Daltons between 'light' and 'heavy' reagents. |
