title: Sequence analysis of two ScFv genes of MAbs against Streptococcus mutans glucosyltransferase.
abstract: 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 present study, we analyzed the nucleotide sequences of molecularly cloned ScFv genes (named ScFv/P126 and ScFv/P136), compared them in three complementarity- determining regions (CDRs), and also located their gene loci originate. Our results showed no particular relationship between the two ScFvs, and suggested the use of a certain type of VH or VL gene segment as well as possible evidence of the ability of these two MAbs to recognize different epitopes of GTF proteins.
authors.affiliation: Department of Biochemistry and Molecular Biology, Nihon University School of Dentistry at Matsudo, Matsudo, Chiba, Japan.
authors.forename: Kimi
authors.initials: K
authors.lastname: Matsumoto
authors.forename: Yasuko
authors.initials: Y
authors.lastname: Shibata
authors.forename: Teruaki
authors.initials: T
authors.lastname: Shiroza
authors.forename: Kazuo
authors.initials: K
authors.lastname: Fukushima
authors.forename: Yoshimitsu
authors.initials: Y
authors.lastname: Abiko
mesh_terms: D000595:Amino Acid Sequence; D000911:Antibodies, Monoclonal / Q000235:genetics*; D001483:Base Sequence; D022801:Complementarity Determining Regions; D004269:DNA, Bacterial; D005964:Glucosyltransferases / Q000276:immunology*; D007128:Immunoglobulin Fragments / Q000737:chemistry / Q000235:genetics*; D008969:Molecular Sequence Data; D012689:Sequence Homology, Nucleic Acid; D013295:Streptococcus mutans / Q000201:enzymology*
chemical_list: D000911:Antibodies, Monoclonal; D022801:Complementarity Determining Regions; D004269:DNA, Bacterial; D007128:Immunoglobulin Fragments; D005964:Glucosyltransferases