The mass spectrometric identification of dipeptide mixtures obtained from dipeptidylaminopeptidase. I—hydrolysates

Publisher Website
Google Scholar
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.