FIG. 5.

Characterization of FH interaction with Y. enterocolitica. The effects of NaCl (A) and heparin (B) on the binding of purified FH to Y. enterocolitica O:3 strains YeO3 (SP YAOC), YeO3-Ail (SP Y-OC), YeO3-c-OCR (SP -A--₂), and YeO3-c-Ail-OCR (SP ---) are shown. Bacteria were incubated with FH (final concentration, 30 μg/ml) in 1/3 PBS with various amounts of NaCl (100 to 650 mM) or heparin (0 to 1,000 μg/ml). Following incubation, the bacteria were washed and whole-cell lysates were subjected to 8% SDS-PAGE and immunoblotting with the nonadsorbed goat antiserum against human FH. Quantitative analysis of FH binding was performed with the NIH ImageJ software. The intensities of the FH protein bands were quantitated, and the influence of loading differences was eliminated by relating the values to the intensity of a nonspecifically reacting bacterial protein band in the same lane (loading control [LC]). The FH-binding level of the bacteria incubated in 1/3 PBS alone was set to 100, and the FH-binding level of the bacteria in 1/3 PBS supplemented with NaCl (100 to 650 mM) and heparin (1 to 1,000 μg/ml) was expressed relative to the FH-binding level of the bacteria in 1/3 PBS alone. The factors expressed by the strains tested are marked as in Fig. 1.