Abstract
Two kinds of N-acetylmuramidase, M-l and M-2 enzymes, that were isolated from the cultural broth of Stm. globisporus 1829, were remarkably different in amino acid composition, immunological properties and modes of lytic action from each other. The M-l enzyme was composed of 186 amino acid residues of which two moles were of half cystine, while the M-2 enzyme was composedof 99 amino acid residues with no cysteine. The hydrolyzing action of the M-2 enzyme was suppressed by the presence of an N-acetyl group on muramic acid residues in the peptidoglycan moiety, while that of the M-l enzyme was independent of the presence of N-acetyl groups. However, the hydrolyzing activity of both enzymes was enhanced when some muramicacid residues were substituted with stem peptides containing alanine, isoglutamine and lysine.
