Western blotting analysis of antibodies to prostate-specific antigen: Specificities for prostate-specific antigen and prostate-specific antigen fragments

Approximately 40% of the prostate-specific antigen (PSA) purified from semi nal fluid comprises cleaved or fragmented forms of PSA. These fragments are observed by reduced SDS-PAGE and have been identified in preparations of p urified seminal plasma. The comparative analysis of 53 antibodies, submitte d to an international PSA Workshop, with different PSA variants was studied using SDS-PAGE and Western blotting. Six different patterns of reactivity were observed which may reflect different epitopes recognized by this panel of antibodies. Additional antibody studies to nonreduced intact PSA sugges t the epitopes are conformation-dependent.