title: The mass spectrometric identification of dipeptide mixtures obtained from dipeptidylaminopeptidase. I--Hydrolysates.
abstract: The amino acid sequence of a polypeptide can be deduced by an identification of all the dipeptides obtained from a Dipeptidylaminopeptidase I hydrolysate of the original polypeptide and its des N-terminal amino acid derivative. The components of such dipeptide mixtures can be readily identified from the chemical ionization (helium) mass spectra of their N-ethoxycarbonylpropenyl methyl ester derivatives without prior separation. The pyrolytic conversion of N-protected peptide dimethyltrideuteromethyl anilinium salts to their methyl esters in the direct insertion probe of a mass spectrometer was found to be most suitable for the derivatization of such dipeptide mixtures.
mesh_terms: D000595:Amino Acid Sequence; D055598:Chemical Phenomena; D002621:Chemistry; D004151:Dipeptides / Q000032:analysis*; D010450:Endopeptidases; D013058:Mass Spectrometry; D008745:Methylation; D011492:Protein Hydrolysates
chemical_list: D004151:Dipeptides; D011492:Protein Hydrolysates; D010450:Endopeptidases