Affiliation:
1. Department of Biology, Washington University, St. Louis, Missouri 63130, USA.
Abstract
An inhibitor of Streptococcus sobrinus endodextranase was detected in the extracellular fractions of UAB66 mutants identified following ethyl methanesulfonate mutagenesis as either devoid of dextranase activity (Dex-) or overproducing water-soluble glucan. The two groups of mutants had the same phenotype and displayed no dextranase activity in assays of extracellular fractions (H. Murchison, S. Larrimore, and R. Curtiss III, Infect. Immun. 34:1044-1055, 1981) and had been shown to be defective in adherence (Adh-) and capable of inhibiting adherence of wild-type strains during cocultivation in vitro (H. Murchison, S. Larrimore, and R. Curtiss III, Infect. Immun. 50:826-832, 1985) and in vivo in gnotobiotic rats (K. Takada, T. Shiota, R. Curtiss III, and S. M. Michalek, Infect. Immun. 50:833-843, 1985). By analysis of proteins in Western blots (immunoblots) and following blue dextran-sodium dodecyl sulfate-polyacrylamide gel electrophoresis (BD-SDS-PAGE), it was demonstrated that these Dex- mutants did synthesize enzymatically active dextranase. From the results of mixing experiments, it was determined that these Dex- Adh- mutants produced enhanced amounts of a cell surface-localized or a cell-associated dextranase inhibitor (Dei). Dei was heat stable but trypsin sensitive. By adding excess dextranase following BD-SDS-PAGE, Dei was detected as blue bands with apparent molecular masses of 43, 40, 37, 27, and 23 kDa. Dei competitively inhibits dextranase activity and is synthesized by wild-type S. sobrinus strains, with the amount varying depending upon growth medium and stage in the growth cycle. R. M. Hamelik and M. M. McCabe (Biochem. Biophys. Res. Commun. 106:875-880, 1982) previously described a Dei in a wild-type S. sobrinus strain.
Publisher
American Society for Microbiology
Subject
Molecular Biology,Microbiology
Reference41 articles.
1. Barrett J. F. T. A. Barrett and R. Curtiss III. 1986. Biochemistry and genetics of dextranase from Streptococcus mutans 6715 p. 205-215. In S. Hamada S. Michalek H. Kiyono L. Menaker and J. McGhee (ed.) Molecular microbiology and immunology of Streptococcus mutans. Elsevier Science Publishing Inc. New York.
2. Purification and partial characterization of the multicomponent dextranase complex of Streptococcus sobrinus and cloning of the dextranase gene;Barrett J. F.;Infect. Immun.,1987
3. Renaturation of dextranase activity from culture supernatant fluids of Streptococcus sobrinus after sodium dodecyl sulfate polyacrylamide gel electrophoresis;Barrett J. F.;Anal. Biochem.,1986
4. Effects of dextranase on cariogenic and acariogenic dextrans;Bowen W. H.;Br. Dent. J.,1968
5. Coykendall A. I. and K. B. Gustafson. 1986. Taxonomy of Streptococcus mutans p. 21-28. In S. Hamada S. Michalek H. Kiyono L. Menaker and J. McGhee (ed.) Molecular microbiology and immunology of Streptococcus mutans. Elsevier Science Publishing Inc. New York.
Cited by
4 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献