Original Paper

Inhibition of Catalytic and Glucan-Binding Activities of a Streptococcal GTF Forming Insoluble Glucans
W.G. Wright^a, C. Thelwell^a, B. Svensson^b, R.R.B. Russell<sup>a

a</sup>Department of Oral Biology, Dental School, University of Newcastle upon Tyne, UK, and
^bDepartment of Chemistry, Carlsberg Laboratory, Copenhagen Valby, Denmark

Address of Corresponding Author

Caries Res 2002;36:353-359 (DOI: 10.1159/000065962)

  Key Words

• Glucosyltransferase
• Inhibition
• Streptococcus

  Abstract

The ability of a range of potential inhibitors to affect the catalytic activity or binding of dextran by a glucosyltransferase (GTF-I) that synthesises insoluble 1,3-linked glucan was tested. Acarbose, deoxynojirimycin, N-dodecyldeoxynojirimycin and Tris, which are thought to interfere with the active site of the enzyme of GTF and related glycosidases, inhibited glucan synthesis but not glucan binding. Tris was found to act as a competitive inhibitor of GTF-I. The effectiveness of the active site inhibitors was not altered by immobilisation of GTF-I on saliva-coated hydroxyapatite. In contrast, three amine hydrofluorides were markedly less effective against immobilised GTF than soluble GTF. The pH of the reaction mixture was found to have a strong influence on inhibition by acarbose, Tris and amine hydrofluorides, a finding that is of direct relevance to use of inhibitors in vivo.

Copyright © 2002 S. Karger AG, Basel

  Author Contacts

R.R.B. Russell
Department of Oral Biology
Dental School, University of Newcastle upon Tyne
Newcastle upon Tyne, NE2 4BW (UK)
Tel. +44 191 222 7859, Fax +44 191 222 6137, E-Mail r.r.russell@ncl.ac.uk

  Article Information

This work was funded by GABA International.

Received: Received: December 21, 2001
Accepted after revision: July 11, 2002
Number of Figures : 3, Number of Tables : 1, Number of References : 45