Degradation of Bacterial Surface Carbohydrates by Virus-associated Enzymes

Virus-associated glycanases acting on bacterial capsular polysaccharides or on the 0-specific side chains of cell wall lipopolysaccharides, carboxylic ester and amide hydrolases removing 0— and N—acetyl residues from these glycans, as well as lyases for bacterial 2xopolysaccharides are known to occur on bacteriophages for different bacterial species, notably for many belonging to the family of Enterobacteriaceae. A review of the current knowledge on this group of enzymes is presented, covering the following aspects: (i) Isolation and selection of appropriate bacteriophages, (ii) purification of bacteriophage particles and of the virus organelles ('spikes" or thick "fibers") carrying the active center(s) , (iii) electron microscopy of the viruses, (iv) molecular properties of the virus organelles, (v) enzymology (pH dependence, kinetics, substrate specificity etc.) of the reactions as catalyzed by complete bacteriophage particles, (vi) applications of the viral glycanases, which allow the preparative isolation of oligosaccharides consisting of one and more repeating units of the host surface heteropolysaccharides.