Sequence Analysis of Two ScFv Genes of MAbs Against Streptococcus mutans Glucosyltransferase

Streptococcus mutans glucosyltransferases (GTFs) are considered to be the principal etiological agents of dental caries. Water-insoluble glucans (WIG) synthesized by those GTFs mediate sucrose-enhanced colonization for the bacterium on tooth surfaces and form dental plaque. GTFs have two functional domains, that is, an N-terminal catalytic sucrose-binding domain involved in sucrose hydrolysis and a C-terminal glucan-binding domain involved in the binding of the synthesized glucan polymer. Two hybridomas, each producing a monoclonal antibody (MAb) that inhibits the WIG synthesis by WIG synthesized GTF (GTF-I), were constructed. Those MAbs, P126 and P136, were shown to be able to recognize the different epitope domains in GTF; P126 recognized the N-terminal region, whereas P136 recognized the C-terminal region. We previously constructed two single chain fragments of immunoglobulin variable regions (ScFvs), which are capable of inhibiting GTF activity, from mice hybridomas producing P126 and P136. In the pre...