Autolytic Enzyme System of Clostridium botulinum

II. Mode of Action of Autolytic Enzymes in Clostridium botulinum Type A

Abstract

The mode of action of the autolytic enzymes of Clostridiumt botulinumt type A strain 190L was investigated using a partially purified autolysin. The autolysin completely solubilized SDS-treated cell walls of the organism, liberating 1.2 moles of NH₂-terminalL-alanine and 0.6 moles of reducing groups per mole of glutamic acid. Neither the NH₂-termini of other amino acids nor COOH-termini of any amino acids were released, These results show that the autolysin contains an N-acetylmuramyl-L-alanine amidase and a hexosaminidase. A disaccharide and peptides were isolated from the wall lysate in a chromatographically homogeneous state. The reducing end of the disaccharide was elucidated to be N-acetylglucosamine by borohydride reduction. This fact indicates that the hexosaminidase is likely to be an endo-β-N-acetylglucosaminidase. A possible structure of the cell wall peptidoglycan is proposed.