Abstract
Sucrose catabolism by Streptococcus mutans is initiated by a phosphoenolpyruvate-dependent sucrose phosphotransferase reaction that produces sucrose 6-phosphate the latter is then cleaved by a sucrose 6-phosphate hydrolase reaction that yields glucose 6-phosphate and fructose. We have examined the regulation of the sucrose 6-phosphate hydrolase and found that it was synthesized constitutively whereas sucrose phosphotransferase activity was inducible. However, the levels of both sucrose phosphotransferase and sucrose 6-phosphate hydrolase were repressed when fructose was used as a growth substrate. The specific activity of sucrose 6-phosphate hydrolase in permeabilized cells was approximately 30 mmol/min per mg (dry weight of cells), and it had an apparent Km for sucrose 6-phosphate of 0.3 mM. analysis of a mutant that was missing sucrose 6-phosphate hydrolase activity revealed that its ability to hydrolyze sucrose was reduced.
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Gabriel O., Wang S. F. Determination of enzymatic activity in polyacrylamide gels. I. Enzymes catalyzing the conversion of nonreducing substrates to reducing products. Anal Biochem. 1969 Mar;27(3):545–554. doi: 10.1016/0003-2697(69)90068-2. [DOI] [PubMed] [Google Scholar]
- Kunst F., Pascal M., Lefesant J. A., Walle J., Dedonder R. Purification and some properties of an endocellular sucrase from a constitutive mutant of Bacillus subtilis Marburg 168. Eur J Biochem. 1974 Mar 1;42(2):611–620. doi: 10.1111/j.1432-1033.1974.tb03376.x. [DOI] [PubMed] [Google Scholar]
- LELOIR L. F., CARDINI C. E. The biosynthesis of sucrose phosphate. J Biol Chem. 1955 May;214(1):157–165. [PubMed] [Google Scholar]
- St Martin E. J., Wittenberger C. L. Characterization of a phosphoenolpyruvate-dependent sucrose phosphotransferase system in Streptococcus mutans. Infect Immun. 1979 Jun;24(3):865–868. doi: 10.1128/iai.24.3.865-868.1979. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wittenberger C. L., Beaman A. J., Lee L. N. Tween 80 effect on glucosyltransferase synthesis by Streptococcus salivarius. J Bacteriol. 1978 Jan;133(1):231–239. doi: 10.1128/jb.133.1.231-239.1978. [DOI] [PMC free article] [PubMed] [Google Scholar]