A New Method for Protein Sequence Analysis Using Edman-degradation, Field-desorption Mass Spectrometry and Computer Calculation. Sequence Determination of the N-Terminal BrCN Fragment of Streptomyces erythraeus Lysozyme

A new method is described for protein sequence analysis. The principle is realized as follows: 1) determination by field-desorption mass spectrometry of the molecular weights of the constituents in peptide mixtures prepared from a polypeptide or protein by specific cleavage methods, 2) quantitation of the 3-phenyl-2-thiohydantoin derivatives of amino acids liberated successively from the constituent peptides in 1) by Edman-degradation, and 3) determination of amino acid sequences with a computer from the data obtained in 1) and 2). The method was applied to sequence determination of a polypeptide of unknown structure, the N-terminal BrCN fragment of Streptomyces erythraeus lysozyme.