FIG. 2.

Immunodetection of MIP in C. trachomatis EB and in cultures of E. coli M15(pREP4) overexpressing WT rMIP-His₆ and the C20A rMIP-His₆ variant. Proteins were separated by 12% Tris-glycine SDS-PAGE, blotted onto a membrane, and detected with rabbit polyclonal anti-MIP IgG and HRP-conjugated goat anti-rabbit IgG. Molecular mass markers (in kilodaltons) are indicated on the left. In cultures of rMIP, two forms of the protein were detected. The solid arrow indicates the position of a protein of about 32 kDa, consistent in MW with the precursor-like forms and present in both WT rMIP-His₆ and the C20A rMIP-His₆ variant. The open arrow indicates the position of a protein of about 27.6 kDa, consistent in MW with the mature-like form and present only in WT rMIP-His₆. In C. trachomatis EB, the MW of the mature form is about 1 kDa lower than that in WT rMIP due to the absence of the His₆ tag in the COOH-terminal position.