CHEMICAL COMPOSITION OF CELL WALL PEPTIDOGLYCAN FROM CLOSTRIDIUM SACCHAROPERBUTYLACETONICUM STUDIED WITH PHAGE ENDOLYSINS AND GAS CHROMATOGRAPHY

Abstract

The enzymic digest of cell wall peptidoglycan from Clostridium saccharoperbutylacetonicum by phage HM 7 endolysin (N-acetylmuramyl-L-alanine amidase) was separated into two constituents on ion-exchange chromatography. One was a polysaccharide, which contained N-acetylglucosamine and N-acetylmuramic acid in the molar ratio of 1.00:0.78. This polysaccharide was digested by phage HM 3 endolysin (N-acetylmuramidase), and the digested product was a saccharide composed of N-acetylglucosamine and N-acetylmuramic acid. The other was a peptide composed of glutamic acid, alanine, and diaminopimelic acid in the molar ratio of 1.00:2.09:1.05. Amino acid sequence of the isolated peptide was determined by Edman degradation method, and optical configuration of the component amino acids was confirmed by gas chromatography using their N-trifiuoroacetyl menthyl esters. These analyses indicated that the isolated peptide was composed of a tetrapeptide subunits of NH₂-terminal-L-Ala-D-Glu-Dpm-D-Ala. A reasonable structure for the cell wall peptidoglycan was also proposed.