Confirmation of the primary structure of thymosin α1 by microsequence analysis of limited acid and enzymatic hydrolysis fragments

The primary structure of the 28-peptide thymosin α1 as determined by Goldstein et al. (1) has been confirmed by independent procedures. Limited dilute acid digestion generated a 26-peptide and a 22-peptide both extending to the C-terminal and lacking the N-terminal blocking group. A combination of Edman microsequencing, carboxypeptidase Y and thermolysin digestion, and fast atom bombardment mass spectrometry was used.