Bovine sperm plasma membrane proteomics through biotinylation and subcellular enrichment

Mammalian fertilization requires a complex interplay between a sperm cell and an oocyte. A significant proportion of these functions are mediated through the proteomic composition of the sperm surface. These proteomic constituents can present as biomarkers to control and regulate breeding of agricultural animals. Previous studies have addressed the composition of bovine sperm cell apical plasma membrane proteome with nitrogen cavitation enrichment. Alternative workflows would enable to expand the compositional data more globally around the entire sperm’s surface. We used a cell-surface biotin-labelling in combination with differential centrifugation to enrich bovine sperm surface proteins. Using nano-LC MS/MS, 338 proteins were confidently identified in the plasma membrane enriched proteome. These results were bioinformatically analysed to assess the purification and to highlight the potential protein-protein interaction networks on the sperm cell surface. A highly significant degree of enrichment was found for transmembrane and plasma membrane proteins, among them proteins previously not described on bovine sperm (CPQ, CD58, CKLF, CPLV, GLB1L3 and LPCAT2B). Functional categories of sperm-egg interaction, protein turnover, metabolism as well as molecular transport, spermatogenesis and signal transduction were represented by proteins with high quantitative signal in our study. A descriptive overview of the bovine sperm plasma membrane integral and peripheral proteins is provided to complement future studies on animal reproduction and its relation to sperm cell surface.