Secretory expression of a novel human spermatozoa antigen in E. coli and its application to a protein chip.

Objective: To produce a recombinant spermatozoa antigen peptide using the E. coli: PhoA system on a protein chip for screening anti-sperm antibodies (ASA). Results: The purity of the recombinant spermatozoa antigen exceeded 95% after two-step purification, as assessed using SDS-PAGE and HPLC. The diagnostic performance of a protein chip coated with the recombinant antigen peptide was evaluated by examining ASA in 51 infertile patients in comparison with a commercial ELISA kit. The area under the receiver operating characteristic curve (AUC) was 0.944, which indicated that the protein chip coated with recombinant spermatozoa antigen peptide was consistent with ELISA for ASA detection. Conclusion: A recombinant spermatozoa antigen was expressed in the E. coli PhoA secretory expression system and its potential application for clinical ASA detection was validated. [ABSTRACT FROM AUTHOR]