ANALYSIS OF THE ENZYMATIC CLEAVAGE (BETA-ELIMINATION) OF THE CAPSULARK5 POLYSACCHARIDE OF ESCHERICHIA-COLI BY THE KS-SPECIFIC COLIPHAGE - A REEXAMINATION

The capsular K5 polysaccharide of Escherichia coli is the receptor of the capsule-specific coliphage K5, which harbors an enzyme that degrad es the capsular K5 polysaccharide to a number of oligosaccharides. Ana lysis of the degradation products using gel permeation chromatography, the periodate-thiobarbituric acid and bicinchoninic acid reactions, a nd nuclear magnetic resonance spectroscopy showed that the major react ion products are hexa-, octa-, and decasaccharides with 4,5-unsaturate d glucuronic acid (Delta(4,5)GlcA) at their nonreducing end. Thus, the bacteriophage enzyme is a K5 polysaccharide lyase and not, as we had reported previously, an endo-N-acetylglucosaminidase.