STRUCTURES OF CELL WALL PEPTIDOGLYCANS OF STAPHYLOCOCCUS EPIDERMIDIS TEXAS-26 AND STAPHYLOCOCCUS AUREUS COPENHAGEN .I. CHAIN LENGTH AND AVERAGE SEQUENCE OF CROSS-BRIDGE PEPTIDES

In the cell wall peptidoglycans of Staphylococcus aureus strain Copenhagen and Staphylococcus epidermidis strain Texas 26, all A-acetylmuramic acid residues are substituted by peptide subunits, carrying pentapeptides on the ɛ-amino groups of their lysine residues. These pentapeptides are cross-linked to dalanine residues in neighboring peptide subunits to the extent of 75 and 66%, respectively, forming oligopeptides of randomly distributed chain length with aminoterminal Nɛ-Cpentapeptidylj-L-lysine at one end and carboxy-terminal L-lysyl-D-alanyl-D-alanine at the other. About 6% of the S. aureus cross-bridge pentapeptides are glycyl-seryl-glycyl-glycyl-glycine, the rest being pentaglycine. In the 5. epidermidis peptidoglycan, serine is nonrandomly distributed in the cross-bridge pentapeptides, and accounts for about 23, 7, 68, 4, and 3% of their residues, starting from their N termini. Both organisms have a strict alternation of N-acetylglucosamine and N-acetylmuramic acid in their glycan, and contain a teichoic acid substituted by D-alanyl and N-acetylglucosaminyl residues. © 1969, American Chemical Society. All rights reserved.