Recombinant expression of porcine spermadhesin AWN and its phospholipid interaction: Indication for a novel lipid binding property

AWN is a porcine (Sus scrofa domestica) seminal plasma protein and has been linked to a variety of processes related to fertilization. To acquire the protein in sufficient amount and purity for functional studies, we established its recombinant expression in E. coli and a three‐step purification protocol based on different chromatographies. The test for AWN–phospholipid interaction revealed phosphatidic acid and cardiolipin as potential binding partners. As phosphatidic acid is surmised to play a role in cation‐induced membrane destabilization and fusion events, we propose a membrane protective function of the presented binding affinity. Further studies with recombinant AWN will allow new insights into the mechanism of sperm–spermadhesin interaction and might provide new approaches for artificial reproduction techniques.