Identity of prostate specific antigen and the semen protein P30 purified by a rapid chromatography technique

Previous investigators have reported the identity of prostate specific antigen (PSA) and the semen protein p30, but data to support these claims have not been published. We report here the rapid and continuous purification of PSA using a simple two column chromatography technique originally developed for purification of p30. Using commercial antisera to PSA and original antisera to p30 for detection, we show that the two glycoproteins have identical purification profiles by this technique which uses cation exchange chromatography and sizing chromatography. The antigens also have identical molecular weights by gel electrophoresis and gel filtration. Furthermore, both antigens correspond to the same prominent protein band in seminal plasma by sodium dodecylsulfate polyacrylamide gel electrophoresis. On commercial immunoassay for PSA, purified p30 gives a calibration curve identical to the commercial PSA kit calibrator (Pros-checkTM PSA Radioimmunoassay, Yang Laboratories). We conclude that PSA and the semen protein p30 are identical and can be easily purified by a rapid continuous technique.