Identification of Renibacterium salmoninarum surface proteins by radioiodination

Surface exposed proteins of Renibacterium salmoninarum were identified by radiolabelling whole bacterial cells with 125I, followed by SDS-PAGE and autoradiography. The most prominent bands had molecular masses of approximately 57 kDa and 22 kDa; in addition, some less intensively labelled bands were detected. Polyclonal sera raised against the 22 kDa protein did not react with the 57 kDa protein. N-terminal amino acid sequence analysis of the purified 22 kDa protein showed no similarity with the sequence of the 57 kDa protein.