FIG. 1.

Temperature and pH influence BBK32 protein expression in B. burgdorferi. Infectious clone BbAH130 (wt) or the isogenic BBK32 gene mutant (bbk32⁻) was cultivated in BSK-H medium at various temperatures or pHs. Spirochetes were harvested at the late logarithmic phase of growth (∼5 × 10⁷ spirochetes/ml), and whole-cell lysates (5 × 10⁷ spirochetes/gel lane) were subjected to immunoblot assays. (A) Specificity of monoclonal antibody directed against the BBK32 protein. Spirochetes were cultivated at 37°C and pH 7.5. The band corresponding to the BBK32 protein is indicated on the right. (B) (Top panel) Coomassie blue-stained gel. The band corresponding to OspC is indicated by an arrow. (Bottom panels) Immunoblots with monoclonal antibodies against the BBK32 protein or FlaB (loading control).