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Effects of exogenous insoluble glucan primer on insoluble glucan synthesis by Streptococcus mutans
Abstract:
The effects of exogenous glucans on WIG synthesis by S. mutans were investigated by turbidimetric measurement. The rapid synthesis of WIG by an enzyme preparation from PS-14 culture fluid proceeded after a lag period of several min. The addition of exogenous WIG, which was previously prepared using the PS-14 enzyme, caused a marked reduction of the lag period with little change in the reaction rate. The length of lag period was affected by the concentrations of WIG primer, enzyme and salts, and the reaction pH. The WIGs from other strains and the periodate-treated WIGs also exhibited effects similar to the PS-14 glucan. In contrast, dextran, starch, dextrin, laminarin, cellulose, chitin, and inulin were without any effect. These results suggest that such lag-reducing effect is specific to glucans containing a significant amount of alpha-(1 leads to 3) linkages.
Insights
Exogenous glucans, specifically those with alpha-(1 leads to 3) linkages, significantly reduce the lag period for water-insoluble glucan (WIG) synthesis by S. mutans. This priming effect accelerates WIG production without altering the reaction rate.
Area of Science:
- Microbiology
- Biochemistry
- Oral Health Research
Background:
- Streptococcus mutans (S. mutans) synthesizes water-insoluble glucans (WIGs) crucial for dental plaque formation.
- Understanding the regulation of WIG synthesis is key to developing strategies for preventing cavities.
Purpose of the Study:
- To investigate the impact of exogenous glucans on the kinetics of WIG synthesis by S. mutans.
- To determine the structural specificity of glucans that influence WIG synthesis.
Main Methods:
- Turbidimetric measurements were used to monitor WIG synthesis.
- Enzyme preparations from S. mutans PS-14 culture fluid were employed.
- Various exogenous glucans and polysaccharides were tested for their effects on the lag period and reaction rate.
Main Results:
- Exogenous WIG, prepared using the PS-14 enzyme, markedly reduced the lag period for WIG synthesis.
- The lag period was influenced by WIG primer concentration, enzyme concentration, salt concentration, and pH.
- Glucans with alpha-(1 leads to 3) linkages showed a specific lag-reducing effect, while other polysaccharides like dextran and cellulose did not.
Conclusions:
- The lag-reducing effect of exogenous glucans is specific to those containing alpha-(1 leads to 3) linkages.
- Priming with specific glucans can accelerate the initiation of WIG synthesis by S. mutans.
- These findings offer insights into the enzymatic mechanisms of glucan synthesis and potential targets for intervention.