Characterization and protective effect of a 29 kDa protein isolated from Coxiella burnetii by detergent Empigen BB.

A 29 kDa protein, isolated from the outer membrane of Coxiella burnetii, strain Nine Mile phase I by detergent Empigen BB, was characterized. The failure in removing lipopolysaccharides (LPS) from preparations of the protein by the purification method used indicates a strong binding between proteins and LPS in the outer membrane of C. burnetii. The protein was immunogenic in mice and protected them against virulent C. burnetii challenge.