Quantitative Bausteinanalyse der Stützmembran in der Zellwand von Escherichia coli B

The three concentric layers of the cell wall of E. coli B (the outer lipoprotein layer, the intermediate lipopolysaccharide layer and the inner protein- and mucopolymer containing rigid layer) contribute 60%, 12% and 21%, respectively, to the total weight of the cell wall. — Treatment of the rigid layer with proteolytic enzymes removes the bulk of its protein components but leaves it otherwise intact: still rigid and cell-shaped, it is found to contain glucose, lipid and the mucopeptide constituents muramic acid, glucosamine, diaminopimelic acid, glutamic acid and alanine in molar ratios corresponding to the chemical compositions of known enzymatic mucopolymer split-products from E. coli-walls. Quantitative balance sheets of these components are made up and their implications on the structural concept of the rigid layer are discussed.