Analysis of B. hermsii DAH BipA after 0-, 30-, 60-, 90-, and 120-min incubations with proteinase K. The top panel was probed with anti-rBipA immune sera, while the bottom panel was probed with an anti-flagellin monoclonal antibody. Also, (−) PK indicates untreated spirochetes that were incubated at 37°C for the duration of the assay. Molecular mass standards are indicated on the left of the immunoblot in kilodaltons.