Bacteriophage-associated lyase activity against Klebsiella serotype K64 capsular polysaccharide.

Bacteriophage phi 64 possesses a lyase that depolymerises the capsular polysaccharide of Klebsiella K64 into a hexasaccharide having an unsaturated derivative of glucuronic acid at the non-reducing end (1). The unsaturated hex-4-enuronic acid residue generated was characterised spectroscopically (u.v. and n.m.r.) and by g.l.c.-m.s. after hydrogenation of the double bond. Partial hydrolysis, Smith degradation, methylation analysis, and n.m.r. spectroscopy have been used to establish the structures of oligosaccharides produced from the polysaccharide. Evidence from 1H-n.m.r. spectroscopy indicates that the D-Man rho residue that undergoes fission is beta. (Formula: see text).