STRUCTURE OF CELL WALL OF STAPHYLOCOCCUS AUREUS .9. MECHANISM OF HYDROLYSIS BY L11 ENZYME

The mechanism of solubilization of the cell walls of Staphylococcus aureus by the L11 enzyme from Flavobacterium has been investigated. This enzyme is an endopeptidase which catalyzes the hydrolysis of both D-alanyl-glycine and glycyl-glycine linkages (in the ratio 3 to 7) in the interpeptide bridge which interconnects peptidoglycan strands in the cell wall of S. aureus strain Copenhagen. In intact cell walls of this strain N-acetylmuramyl-L-alanine linkages are also cleaved, but this linkage is not hydrolyzed in some other substrates for this enzyme. After the interpeptide bridges have been opened a relatively slow secondary hydrolysis results in the liberation of small glycine peptides. This enzyme thus belongs to a group of enzymes which are known to catalyze the hydrolysis of the pentaglycine bridge in S. aureus. © 1968, American Chemical Society. All rights reserved.