Xylitol disturbs protein synthesis, including the expression of HSP‐70 and HSP‐60, in <i>Streptococcus mutans</i>
Bibliographic record
Abstract
Xylitol, a natural sugar alcohol and a caries-preventive carbohydrate sweetener, inhibits xylitol-sensitive wild-type Streptococcus mutans but also selects for its natural xylitol-resistant mutants. The aim of the work was to verify the influence of xylitol on heat shock proteins HSP-60 (GroEL-like) and HSP-70 (DnaK-like) in xylitol-sensitive and xylitol-resistant strains. Cells from fresh isolate S. mutans 123.1 were grown at 37 degrees C and constant pH 7.0. The cell culture was stressed by raising the temperature to 43 degrees C or adding xylitol (4% final). Cell proteins labeled with a cocktail of 14C-amino acids were analyzed by SDS-PAGE and autoradiography whereas HSP-60 and HSP-70 were visualized using Western immunoblotting. In both xylitol-sensitive and xylitol-resistant strains, heat stress was associated with an increase of both HSP-60 (63 kDa) and HSP-70 (71 kDa) and a decrease in the intensity of a number of other protein bands compared with cells maintained at 37 degrees C. Exposure to xylitol but not to other polyols induced a decrease of both these heat shock proteins in the xylitol-sensitive strain but did not modify them in the xylitol-resistant mutant. It also decreased all protein bands above 60 kDa together with a 53 kDa protein and increased the amount of 57-, 50- and 40-kDa proteins in the xylitol-sensitive strain whereas the proteins of the xylitol-resistant strain remained unchanged. The results suggest that xylitol is a strong metabolic inhibitor that disturbs protein synthesis and reduces the expression of HSP-70 and HSP-60 proteins in the wild-type xylitol-sensitive S. mutans but not in the xylitol-resistant natural mutant strain.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".