Multiple Forms of Dextran-Binding Proteins from Streptococcus Mutans

Abstract
Lectins and the carbohydrates to which they bind have been implicated in interspecies and intraspecies cell recognition and adherence in several organisms. The implication of lectins in these processes not only confirms Moscona’s elegant proposal that macromolecules of the eukaryote cell surface mediate the processes of cell recognition and adherence (1), but provides a molecular mechanism for this process and indicates that this mechanism functions in diverse organisms, ranging from bacteria to mammals. Thus, biochemically similar mechanisms for cell recognition and adherence apparently have evolved independently to facilitate biological interactions as different as host recognition of the symbiotic members of the genus Rhizobium by clover root hairs (2), cell aggregation in the cellular slime molds (3,4), fusing of myoblasts into myotubules during chick embryo muscle differentiation (5–7), sperm-egg recognition and attachment (8), the attachment of Streptococcus mutans to host surfaces (9), and, perhaps, the binding of Vibrio cholerae (10) and Escherichia coli (11,12) to host tissues.