Characterization of abnormal human haemoglobins by fast atom bombardment mass spectrometry

A procedure using fast atom bombardment mass spectrometry for mapping the proteolytic digest of alpha-, beta- and gamma-globin chains of normal human haemoglobin was developed. It required the separation of globins prior to their analysis by mass spectrometry of their enzymatic digests. Almost all the expected peptides were identified by direct analysis of the peptide mixture. Peptide recognition along the globin chain sequences was easily made on the basis of their molecular weight and the assignments performed were confirmed submitting the whole peptide mixture to a single step of Edman degradation. The procedure was successfully applied to the structural characterization of three variant human beta-globin chains, demonstrating the general applicability of this mapping procedure in the analysis of haemoglobinopathies.