2D-PAGE proteins from dental biofilms formed in presence of carbohydrates

OBJECTIVE: Sucrose is fermentable to acids as their monosaccharide components (Glucose and Fructose), however it is more cariogenic. The aim of this study was to evaluate if this could be explained by difference in the protein matrix of the dental biofilms formed in presence of these different carbohydrates. METHODS: A palatal appliance containing eight human dental enamel blocks was used by volunteer in three-14-day phases for plaque accumulation. A 20% sucrose solution, or a solution containing a mixture of 10% glucose with 10% of fructose, or distilled, deionized water (negative control), were dripped onto the blocks eight times a day. The volunteer used fluoridated dentifrice three times a day. After 14 days, the biofilm was collected and the matrix proteins were extracted by treating the samples for 1 h under agitation with 50 μL of 0.1N NaOH containing 1 mM EDTA for each mg of dental biofilm. After centrifugation, the protein profile of the supernatant was assessed by isoeletric focusing (pH 4-7) and two-dimension polyacrilamide gel electrophoresis (2D-PAGE). RESULTS: It was found a protein pattern from 10 to 100 kDa. The amount of proteins spots from 10 to 20 kDa was higher in the biofilms formed in absence of sugar and on exposure to glucose+fructose than that formed in presence of sucrose. CONCLUSIONS: The findings suggest that the highest cariogenicity of sucrose may be explained by the proteome found in the biofilm formed in presence of this carbohydrate. (FAPESP 99/07185-7; 02/00293-3; 03/01536-0 and CNPq 472392/03-4).