AEM
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Wilkins, J. C.
Right arrow Articles by Beighton, D.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Wilkins, J. C.
Right arrow Articles by Beighton, D.
Agricola
Right arrow Articles by Wilkins, J. C.
Right arrow Articles by Beighton, D.

Applied and Environmental Microbiology, August 2001, p. 3396-3405, Vol. 67, No. 8
0099-2240/01/$04.00+0   DOI: 10.1128/AEM.67.8.3396-3405.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.

Altered Protein Expression of Streptococcus oralis Cultured at Low pH Revealed by Two-Dimensional Gel Electrophoresis

Joanna C. Wilkins,* Karen A. Homer, and David Beighton

Department of Oral Microbiology, GKT Dental Institute, King's College London, London United Kingdom

Received 14 March 2001/Accepted 25 May 2001

Streptococcus oralis is the predominant aciduric nonmutans streptococcus isolated from the human dentition, but the role of this organism in the initiation and progression of dental caries has yet to be established. To identify proteins that are differentially expressed by S. oralis growing under conditions of low pH, soluble cellular proteins extracted from bacteria grown in batch culture at pH 5.2 or 7.0 were analyzed by two-dimensional (2-D) gel electrophoresis. Thirty-nine proteins had altered expression at low pH; these were excised, digested with trypsin using an in-gel protocol, and further analyzed by peptide mass fingerprinting using matrix-assisted laser desorption ionization mass spectrometry. The resulting fingerprints were compared with the genomic database for Streptococcus pneumoniae, an organism that is phylogenetically closely related to S. oralis, and putative functions for the majority of these proteins were determined on the basis of functional homology. Twenty-eight proteins were up-regulated following growth at pH 5.2; these included enzymes of the glycolytic pathway (glyceraldehyde-3-phosphate dehydrogenase and lactate dehydrogenase), the polypeptide chains comprising ATP synthase, and proteins that are considered to play a role in the general stress response of bacteria, including the 60-kDa chaperone, Hsp33, and superoxide dismutase, and three distinct ABC transporters. These data identify, for the first time, gene products that may be important in the survival and proliferation of nonmutans aciduric S. oralis under conditions of low pH that are likely to be encountered by this organism in vivo.

* Corresponding author. Mailing address: Department of Oral Microbiology, GKT Dental Institute, King's College London, Caldecot Road, Denmark Hill, London SE5 9RW, United Kingdom. Phone: 44 20 7346 3272. Fax: 44 20 7346 3073. E-mail: joanna.wilkins{at}kcl.ac.uk.

Applied and Environmental Microbiology, August 2001, p. 3396-3405, Vol. 67, No. 8
0099-2240/01/$04.00+0   DOI: 10.1128/AEM.67.8.3396-3405.2001
Copyright © 2001, American Society for Microbiology. All rights reserved.


This article has been cited by other articles:



Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
J. Bacteriol. Microbiol. Mol. Biol. Rev. Eukaryot. Cell All ASM Journals

Copyright © 2001 by the American Society for Microbiology. All rights reserved.