FIG. 4.

GTF activity of S. mutans UA130 gbpA gtfBC, gbpA, and wt. Equivalent levels of cell-associated proteins were resolved by SDS-PAGE and incubated at 37°C in PBS (pH 6.5) containing sucrose and Triton X-100. Gels were photographed against a black background. The positions of SDS-PAGE molecular mass standards are indicated in the left margin. The positions of water-insoluble glucan and fructan are indicated in the right margin. Lanes 1 to 6: contain gbpA gtfBC isolates recovered from six individual gbpA mutant-infected gnotobiotic rats from two separate determinations of cariogenicity. Lanes: 1, B3-B; 2, D2-A; 3, C5-2; 4, C3-2; 5, A6-1; 6, A2-1; 7 to 9, laboratory strains (7, gbpA spontaneous gtfBC; 8, gbpA; 9, wt).