Proteomics of semen and its constituents

Abstract

Semen is a complex fluid comprising sperm and other products of the testes together with secretions from the accessory sex glands including the prostate, seminal vesicles, and the bulbourethral gland. Studies of the protein components of seminal fluid, with or without the sperm present, can improve our understanding of reproductive biology; have potential clinical applications in the assessment and treatment of infertility; can assist with the diagnosis and management of urological diseases; and, at times, can offer important forensic insights. This review examines the application of proteomic methods to the study of spermatozoa and seminal fluid and highlights some of the unique challenges associated with the collection, fractionation, and analysis of this fluid. The discussion is restricted to issues relating to human semen, although we make occasional reference to important studies from animals.

Seminal Plasma Proteins: What Role Do They Play?

“…Comprehensive sperm protein databases had been established since the late 1990's 29 with above 1000 spots listed, a number that had increased over time. 15 Proteins identified thus far cover the expected spectrum of function (from energy production to cell recognition), but few, too few, are accurately linked to (in)fertility, thus calling for other methods of isolation of the membranes so that specific areas relevant to capacitation or binding (either to the ZP or to the oolema) are more closely examined. 14 As for the SP, availability of seminal material has not been an issue because volumes are sufficient for analyses for either human or animal studies.…”

“…Interestingly, fluids such as semen appear, in the context of protein identification and relation to function, really complex, ranging from few relevant proteins in spermatozoa towards hundreds in SP. 15 Moreover, the fact that ejaculation is in many species fractionated adds a new dimension to the action of SP proteins (and their interaction) on sperm function and on female reactivity. This paper attempts to review aspects of the composition of the seminal plasma of mammals, with a particular focus on its proteomics and the differential functions this fluid would play in relation to sperm function and signalling to the female, with an ultimate focus on its role in modulating fertility.…”

Analysis and differentiation of seminal plasma via polarized SERS spectroscopy

“…However, we performed one study on blood plasma under different polarization excitations and found that left-handed circularly polarized excitation led to the best result for gastric cancer detection. 10 Most biomolecules are chiral molecules, such as phosphatases, aminopeptidases, glycosidases, hyaluronidase, and mucin, 15 which are also present in the seminal plasma. This motivated us to consider a polarized SERS study on seminal plasma.…”

Molecular heterogeneity of gelatin-binding proteins from human seminal plasma

“…[1]. Introducing proteomic analysis of human seminal fluid has led to more detailed analysis and has indicated a large number of extracellular proteins, proteases and other proteins secreted by testes, prostate and other male accessory glands [2][3][4][5]. However, the structure-function relationship of seminal plasma proteins at the molecular level and the relation of more basic questions to particular clinical end points is still insufficiently explored.…”