Purification and characterization of a major cytoplasmic antigen of Candida albicans

In previous work (Jones, Infect, Immun. 30:78-89, 1980) a major cytoplasmic antigen of Candida albicans was identified. In both humans and experimental animals, this antigen is released from C. albicans during the course of an invasive C. albicans infection and elicits a specific antibody response. In this study, we used diethylaminoethyl cellulose chromatography and concanavalin A-Sepharose chromatography to obtain purified preparations of the major cytoplasmic antigen from crude cytoplasmic extracts of C. albicans. Column chromatography yielded a purified preparation of the major cytoplasmic antigen, which produced a single line in polyacrylamide gel electrophoresis. Using crossed immunoelectrophoresis, we detected small concentrations of contaminating antigens in the purified preparations. We found that the major antigen was a single polypeptide chain containing about 435 amino acid residues and had a molecular weight of 54,300. This antigen did not possess any of 19 common activities. Enzyme linked immunosorbent assays are being developed to detect this antigen in serum and to detect antibody against the antigen.