Amino acid sequencing by gas chromatography-mass spectrometry using perfluoro-dideuteroalkylated peptide derivatives: B. Interpretation of the mass spectra

The mass spectra of the O-trimethylsilylated trifluoro-dideuteroethyl polyamino alcohols, produced by LiAlD₄-reduction and O-trimethylsilylation of N-trifluororacetyl oligopeptide methyl esters, are evaluated. Characteristic mass spectra of derivatives are shown which are derived from peptides containing all protein amino acids including Arg, His, Trp, Gln, Asn and carboxyl terminal amides as well as modified Cys-residues. The mass spectra of these derivatives can be easily interpreted in terms of the amino acid sequence of the original peptides since they contain abundant and intensity-balanced sequence-determining ions.