Journal of Dental Research, Vol 69, 1746-1752, Copyright © 1990 by International & American Associations for Dental Research Online Journals

ARTICLES

Characterization of the alpha-amylase receptor of Streptococcus gordonii NCTC 7868

C. W. Douglas
Department of Oral Pathology, School of Clinical Dentistry, University of Sheffield, United Kingdom.

The purpose of the work described here was to investigate the mechanisms involved in the binding of salivary alpha-amylase to Streptococcus gordonii NCTC 7868 (Challis). Of six types of alpha-amylase studied, only mammalian forms of the enzyme were found to bind to S. gordonii cells. Salivary alpha-amylase binding was inhibited by treatment of cells with trypsin and pronase, but not with pepsin or sodium periodate. Presence of starch, dextrin, or maltoheptaose partially inhibited binding of the enzyme to S. gordonii. Both mutanolysin extracts of cells and culture supernatants contained alpha-amylase-binding activity, which was partially purified by Sepharose CL-6B and DEAE-ion-exchange chromatography. Western blotting detected four putative receptor bands--65 kDa, 15 kDa, 12.5 kDa, and one with a very high molecular weight; the lower-molecular-weight components may be products of proteolytic degradation of the high-molecular-weight material, but their true relationship has yet to be determined. Pre-treatment of salivary alpha-amylase with these putative receptors partially inhibited subsequent binding of the enzyme to S. gordonii cells. When bound to cells, only 19% of the salivary alpha-amylase activity was detectable, suggesting that alpha-amylase binds to the receptor at or near the active site of the enzyme.

This article has been cited by other articles:

				P. E. Benson and C. W. I. Douglas Decontamination of orthodontic bands following size determination and cleaning J. Orthod., March 1, 2007; 34(1): 18 - 24. [Abstract] [Full Text] [PDF]

				J. M. Tanzer, L. Grant, A. Thompson, L. Li, J. D. Rogers, E. M. Haase, and F. A. Scannapieco Amylase-binding proteins A (AbpA) and B (AbpB) differentially affect colonization of rats' teeth by Streptococcus gordonii Microbiology, September 1, 2003; 149(9): 2653 - 2660. [Abstract] [Full Text] [PDF]

				J. D. Rogers, R. J. Palmer Jr., P. E. Kolenbrander, and F. A. Scannapieco Role of Streptococcus gordonii Amylase-Binding Protein A in Adhesion to Hydroxyapatite, Starch Metabolism, and Biofilm Formation Infect. Immun., November 1, 2001; 69(11): 7046 - 7056. [Abstract] [Full Text] [PDF]

				J. D. Rogers and F. A. Scannapieco RegG, a CcpA Homolog, Participates in Regulation of Amylase-Binding Protein A Gene (abpA) Expression in Streptococcus gordonii J. Bacteriol., June 1, 2001; 183(11): 3521 - 3525. [Abstract] [Full Text]

				A. E. Brown, J. D. Rogers, E. M. Haase, P. M. Zelasko, and F. A. Scannapieco Prevalence of the Amylase-Binding Protein A Gene (abpA) in Oral Streptococci J. Clin. Microbiol., December 1, 1999; 37(12): 4081 - 4085. [Abstract] [Full Text]

				Z. E. Juarez and M. W. Stinson An Extracellular Protease of Streptococcus gordonii Hydrolyzes Type IV Collagen and Collagen Analogues Infect. Immun., January 1, 1999; 67(1): 271 - 278. [Abstract] [Full Text] [PDF]