L-methionine (Met) oxidation products in tripeptides, in Met-enkephalin and in the bovine basic pancreatic trypsin inhibitor have been identified by 1H and 13C NMR spectroscopy. The oxidation of Met residues by stoichiometric amounts of chloramine-B, H2O2 and I2 yields a mixture of L-methionine sulfoxide (Met(O)) and dehydro-L-methionine (DH-Met), Met(O) and DH-Met, respectively, at pH 7.0 and 25.0°C. The formation of DH-Met occurs only if the amino-group of Met is not derivatized. The analysis of 1H and 13C NMR spectra allows us to quantitate Met oxidation products, to ascertain the relative proportion of the R and S forms of Met(O) and DH-Met, and to reveal the presence of a Met residue at the N-terminal position in peptides and proteins.
|Number of pages||14|
|Journal||Biochemistry and Molecular Biology International|
|Publication status||Published - 1995|
ASJC Scopus subject areas
- Molecular Biology