Characterization of a chromosomal gene and the antigen it expresses from the Lyme disease agent, Borrelia burgdorferi

The sequence and characterization of a chromosomal gene from the Lyme disease agent Borrelia burgdorferi and the antigen it encodes are described. The gene was cloned and expressed in transformed Escherichia coli cells. The gene is composed of 597 bases and expresses a predicted protein of 199 amino acids. Antibodies specific for the recombinant antigen reacted with a single B. burgdorferi protein with a molecular mass of approximately 22 kDa. The protein was not susceptible to proteinase digestion but was extracted by n- butanol phase partitioning, suggesting a periplasmic location of the antigen. Sera from humans and canines seropositive for B. burgdorferi reacted with the recombinant antigen. The antigen characterized in this report appears to be immunologically significant in naturally infected hosts.