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

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. 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). 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. We have identified over 100 protein and peptide components of normal human seminal fluid.