N-terminal heterogeneity of methylamine dehydrogenase from Thiobacillus versutus

The N-terminal processing of MADH from the bacterium T. versutus and the N-terminal heterogeneity of the isolated alpha subunit of the alpha 2 beta 2 protein complex was demonstrated by a combination of Edman sequence analysis of an electroblotted band, in situ digested with pyroglutamate aminopeptidase, and accurate mass determination of the homogeneous subunit by the technique of electrospray ionisation mass spectrometry. From this study, it appears that the corresponding gene of the alpha subunit contains 395 amino acids and that it is preceded by a leader sequence of 31 residues.