Activity of Streptococcus mutans a-D-Glucosyltransferases Released Under Various Growth Conditions

Abstract

The effect of a variety of growth conditions on extracellular D-glucosyltransferase (GTF) activity of Streptococcus mutans strains in continuous culture has been studied. Maximum GTF activity was found at low growth rates and at pH 6.5, and under this condition the predominant glucosyltransferase was GTF-S, an enzyme that synthesized soluble dextran. At high growth rates, the proportion of GTF-S decreased, and 50% or more of the total glucosyltransferase was GTF-I, an enzyme that synthesized water-insoluble (1→3)-α-D-glucan. Variation in the relative activities of GTF-S and GTF-I results in such diversity in the glucans synthesized from sucrose that it is virtually meaningless to describe a structural analysis of S. mutans glucan without specifying the conditions of growth of the organism.

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References

Hare, M.D. ; Svensson, S. ; and Walker, G.J. : Characterization of the Extracellular, Water-insoluble a-D-Glucans of Oral Streptococci by Methylation Analysis, and by Enzymic Synthesis and Degradation , Carbohydr Res 66:245-264, 1978.

Walker, G.J. and Hare, M.D. : Purification and Properties of Cladosporium resinae (1→3)-α-D-Glucanase, and the Enzymic Hydrolysis of Glucans Synthesised by Extracellular D-Glucosyltransferases of Oral Streptococci , Carbohydr Res 58: 415-432, 1977.

Walker, G.J. ; Morrey-Jones, J.G. ; Svensson, S. ; and Taylor, C. : Effect of Variation in Growth Conditions on the Activity of D-Glucosyltransferases and the Synthesis of a-D-Glucans by Streptococcus mutans OMZ176. In: Glucosyltransferases, Glucans, Sucrose and Dental Caries, Doyle, R.J. and Ciardi, J.E. , Eds., Washington, DC:IRL Press, 1983, pp. 179-187.

Van Houte, J. and Saxton, C.A. : Cell Wall Thickening and Intracellular Polysaccharide in Microorganisms of the Dental Plaque, Caries Res 9:21-35, 1975.

Walker, G.J. ; Hare, M.D. ; and Morrey-Jones , J.G. : Effect of Variation in Growth Conditions on Endo-dextranase Production by Streptococcus mutans , Carbohydr Res 107 :111-122, 1982.

Walker, G.J. ; Murray, V.L. ; and Morrey-Jones , J.G. : Regulation of Dextranase Synthesis by Streptococcus mutans, FEBS Lett 115:206-208, 1980.

Van Handel, E. : Direct Microdetermination of Sucrose, Anal Biochem 22:280-283, 1968.

Ruckel, E.R. and Schuerch, C. : Chemical Synthesis of a Dextran Model, Poly-α-(1→6)-anhydro-D-glucopyranose , Biopolymers 5:515-523, 1967.

Shimamura, A. ; Tsumori, H. ; and Mukasa, H. : Purification and Properties of Streptococcus mutans Extracellular Glucosyltransferase, Biochim Biophys Acta 702:72-80, 1982.

10.

Fukui, K. ; Moriyama, T. ; Miyake, Y. ; Mizutani, K. ; and Tanaka, 0.: Purification and Properties of Glucosyltransferase Responsible for Water-insoluble Glucan Synthesis from Streptococcus mutans, Infect Immun 37:1-9, 1982.

11.

McCabe, M.M. and Smith, E.E. : The Dextran Acceptor Reaction of Dextransucrase from Streptococcus mutans Kl-R, Carbohydr Res 63:223-239, 1978.

12.

Walker, G.J. : Branching-Enzyme Activity of an a-D-Glucosyltransferase of Streptococcus mutans, Carbohydr Res 82: 404-410, 1980.

13.

Robyt, J.F. and Martin, P.J. : Mechanism of Synthesis of D-Glucans by D-Glucosyltransferases from Streptococcus mutans 6715, Carbohydr Res 113:301-315, 1983.

14.

Staat, R.H. ; Gawronski, T.H. ; and Schachtele , C.F. : Detection and Preliminary Studies on Dextranase-Producing Microorganisms from Human Dental Plaque, Infect Immun 8:1009-1016, 1973.