A comprehensive characterization of the peptide and protein constituents of human seminal fluid

BACKGROUND: Knowledge of the peptide and protein components of seminal fluid and their role in prostate diseases including benign prostatic hyperplasia and prostate carcinoma is scant. We have undertaken a proteomic analysis of semen as a forerunner to identifying sensitive and specific diagnostic markers of prostatic diseases; to aid in improved therapeutic intervention; and, to enhance our understanding of prostate health and disease. METHODS: Peptide and protein components of pooled human seminal fluid (n = 5) were separated by gel electrophoresis (1D and 2D) and identified by either matrix-assisted laser desorption ionization-time-of-flight-mass spectrometry (MALDI-TOF-MS) or capillary liquid chromatography tandem mass spectrometry (LC-MS/MS). RESULTS: Analysis by two-dimensional electrophoresis (2DE) established that there were multiple post-translational variants of the majority of the proteins. Hormones, growth factors and bioactive peptides were detected and identified. CONCLUSIONS: We have identified over 100 protein and peptide components of normal human seminal fluid.