Proteomic analysis of seminal plasma from normal volunteers and post-vasectomy patients identifies over 2000 proteins and candidate biomarkers of the urogenital system

Seminal plasma is a fluid that originates from the testis, epididymis,prostate, and seminal vesicles, and hence, proteomic studies may identify potential markers of infertility and other diseases of the genito-urinary tract. We profiled the proteomes of pooled seminal plasma from fertile Control and post-vasectomy (PV) men. PV seminal plasma samples are void of proteins originating from the testis and the epididymis due to ligation of the vas deferens, and hence, comparative analysis of Control and PV data sets allows for identification of proteins originating from these tissues. Utilizing offline MudPIT and high-resolution mass spectrometry, we were able to identify over 2000 proteins in Control and PV pools each and over 2300 proteins all together. With semiquantitative analysis using spectral counting, we catalogued 32 proteins unique to Control, 49 at lower abundance in PV, 3 unique to PV, and 25 at higher abundance in PV. We believe that proteins unique to Control or at lower abundance in PV have their origin in the testis and the epididymis. Public databases have confirmed that many of these proteins originate from the testis and epididymis and are linked to the reproductive tract. These proteins may serve as candidate biomarkers for future studies of infertility and urogenital diseases.