Relative intensities of recognition factors at two combining sites of Ralstonia solanacearum lectin (RSL) for accommodating LFucα1-->, DManα1--> and Galβ1-->3/4GlcNAc glycotopes.

Owing to the weak reactivities of monomeric DManα1 and Galβ1-->3/4GlcNAcβ (I(β)/II(β)) glycotopes with Ralstonia solanacearum lectin (RSL), their recognition roles were previously ignored. In this study, the interaction intensities of RSL toward four monomeric glycotopes LFucα1-->, DManα1--> and I(β)/II(β) within two combining sites were established by both enzyme-linked lectinosorbent and inhibition assays. It was found that high density of LFucα1--> complex enhanced the recognition intensities at LFucα1--> site, polyvalent DManα1--> was essential for binding at the DManα1--> site and polyvalent I(β)/II(β) was required at LFucα1--> site. The peculiar recognition systems of RSL are very different from other well known microbial lectins.