Modification of bacteriophage phi 25 adsorption to Bacillus subtilis by concanavalin A.

The phytohemagglutinin, concanavalin A (Con A), interacts specifically and reversibly with the alpha-d-glucose-substituted polyglycerol phosphate teichoic acids of Bacillus subtilis 168. Teichoic acids from nonglucosylated strains (mutants resistant to phage phi25) interact weakly, if at all, with Con A. Prior treatment of glucosylated cell walls with Con A results in a concentration-dependent inhibition of phage phi25 adsorption. The inhibition of adsorption to glucosylated cell walls occurs immediately upon the formation of the Con A-cell wall complex and is reversed upon dissociation of the complex by addition of alpha-methyl glucose. Examination of the interaction between Con A and whole cells, cell walls, or wall digests from glucosylated (phage-sensitive) and non-glucosylated (phage-resistant) strains further demonstrates the specificity of the reaction. A conditional phage phi25-resistant mutant only forms complexes with Con A when grown under permissive conditions.