Biochemical and Immunological Analyses of the Flagellin of Clostridium tyrobutyricumATCC 25755

The monoclonal antibody 21E7‐B12 (IgG3) can be used in a direct method of Clostridium tyrobutyricumdetection based on an immunoenzymatic assay. Immunoelectron microscopy demonstrated that the 21E7‐B12 antibody recognized the surface‐exposed epitopes on the flagellar filaments of C. tyrobutyricum.After flagellar extraction, the purified flagellin showed an apparent molecular mass of 46 kDa with an isoelectric point of 3.6. Sugar staining, mild periodate oxidation and é‐elimination experiments showed that the flagellin was glycosylated and that the 21E7‐B12 epitope was located in the sugar moiety. Amino acid composition showed that the flagellar filament protein contained a high percentage of serine and threonine, while proline was absent. The first 23 residues of the N‐terminal were determined and sequence homology with other flagellins was found.