Figure 4.

Identification of FH molecules bound to CRASP proteins. Purified, polyhistidine-tagged proteins (10 μg each) coupled onto magnetic beads were incubated with selected animal sera. Immobilized CspA_B31 and CspZ were incubated with horse (A) or rat (B) serum, CspA_PKo with mouse or horse serum (C) and ErpP and ErpC with mouse serum (D). Uncoated beads were also incubated under the same conditions and used as a control to identify non-specific binding of serum proteins. After extensive washing, bound proteins were eluted with 100 mM glycine and the eluate fractions were separated by glycine-SDS-PAGE, following silver staining. Protein bands indicated were cored from stained gels and proteins were identified by mass spectrometry. The mobility of the molecular mass standard is indicated on the left of each panel and recombinant proteins eluted were indicated on the right. The asterisks in panel A, B, and C indicated the protein bands analyzed by mass spectrometry.