The cell wall of Bacillus licheniformis N.C.T.C. 6346. Composition of the mucopeptide component

Abstract

1. The mucopeptide component of wall preparations from Bacillus licheniformis was obtained in soluble form by treatment of the acid-insoluble residue of walls with lysozyme. 2. The soluble mucopeptide contains glutamic acid, diaminopimelic acid, alanine, N-acetylglucosamine and N-acetylmuramic acid in the molecular proportions 1·0:1·0:1·6:0·8:0·7. In addition approx. 1 mole of amide/mole of glutamic acid is present. Essentially all of the dry weight and nitrogen content of soluble mucopeptide is accounted for by these constituents. 3. The optical configurations of the amino acids were determined. Approx. 0·6 mole of d-alanine and 1·0 mole of l-alanine are present/mole of glutamic acid. 4. The structures of several small peptides derived from soluble mucopeptide after mild acid hydrolysis were established. 5. The structure of soluble mucopeptide from B. licheniformis is discussed on the basis of these results together with data on the number of free amino groups present in soluble mucopeptide.