FIG. 7.

Protease treatment affects surface expression of native BsCRASP-1 and BsCRASP-2 and binding to factor H and FHL-1. (A) B. spielmanii A14S cells were incubated with the indicated concentrations of proteinase K or trypsin. After 2 h of incubation, the cells were lysed by sonication, and each protein lysate was subjected to 10% Tris-Tricine SDS-PAGE. BsCRASP-1 and BsCRASP-2 were identified using recombinant FHL-1 and polyclonal antibody αSCR1 to 4 (dilution 1/1,000) specific for the N terminus of FHL-1/factor H by ligand affinity analysis. (B) Flagellin (FlaB) was detected with MAb L41 1C11 (dilution 1/1,000) by Western blotting. (C) Part of a Coomassie-stained 10% Tris-Tricine SDS-polyacrylamide gel is shown to demonstrate the susceptibility of OspA and OspB to proteolytic degradation.