Effect of carbohydrate on TFP retraction. (A) The protease treatment of fibril material was monitored by immunoblotting analysis using mAb 2105 (anti-FibA antibody). Lanes 1–4, various concentrations of DK1622 fibril material (8, 4, 2, and 1 mg/ml, respectively) were treated with 1 mg/ml Pronase E at 37°C for 180 min; lanes 5 and 6: 2 and 1 mg/ml untreated DK1622 fibril material. In each lane, 20 μl samples were loaded. (B) Surface pilin from 4 × 108 SW504 cells before (lane 1) or after (lane 2) incubating SW504 with protein-free fibrils (1.5 mg/ml) as described in Materials and Methods (lane 2). PilA was probed with anti-PilA antibody as for Fig. 3. (C) Lanes 1 and 2, surface pilin from 4 × 108 SW504 before (lane 1) or after (lane 2) incubating SW504 with 1 mg/ml chitin suspension (30 min at 32°C); lanes 3 and 4, pilin isolated from 4 × 108 SW504 before (lane 3) or after incubating isolated pilin with 1 mg/ml chitin suspension (1 h at 37°C). Shown are representative data for triplicate experiments.