FIG. 3.

Treatment of cell-free PDL culture supernatants with T. denticola PrtP protease complex. Supernatants of PDL cultures were incubated with purified T. denticola PrtP protease complex (Td pr) at the indicated final concentrations for 2 h at 37°C. (A) Silver-stained SDS-PAGE of purified T. denticola PrtP protease complex (0.4 μg per lane). Lanes: −, unheated sample showing native PrtP complex; +, heated sample showing protease complex components PrtP, PrcA2, and PrcA1. (B) Gelatin zymogram of protease-treated PDL cell culture supernatants. Bands showing gelatinolytic activity of T. denticola PrtP protease complex and MMP-2 are indicated. (C) Western immunoblot of PDL cell culture supernatants probed with an anti-FN antibody. (D) Western immunoblot of PDL cell culture supernatants treated with T. denticola PrtP protease complex at 100 ng ml⁻¹. Lanes: 1, PDL without Td protease (control); 2, PDL with Td protease; 3, PDL with Td protease pretreated with 2 mM PMSF; 4, PDL with Td protease pretreated by boiling for 5 min; 5, PDL with 2 mM PMSF and without Td protease. The blot was probed with an anti-FN antibody. Numbers on the left of gels indicate molecular weight standards (in thousands).