ORIGINAL ARTICLE Andrology Identification of sperm head proteins involved in zona pellucida binding

what is known already: Regarding sperm–ZP binding, several target spot/proteins have been detected in several species, but not all have been characterized. The limit of these studies was that a mixture of the different ZP glycoproteins was used and did not allow the identification of the specific ZP glycoprotein (ZPA/2, ZPC/3 or ZPB/4) involved in the interaction with the sperm proteins. study design, size, duration: To identify the human sperm proteins interacting with the oocyte ZP, we combined two approaches: immunoblot of human spermatozoa targeted by antisperm antibodies (ASAs) from infertile men and far western blot of human sperm proteins overlayd by each of the rhZP proteins. materials, setting, methods: We used rhZP expressed in Chinese hamster ovary (CHO) cells and ASA eluted from infertile patients undergoing IVF failure. Sperm proteins separated by two-dimensional (2D) electrophoresis recognized by both sperm-eluted ASAs from infertile patients and rhZP were identified by mass spectrometry (MALDI-MS/MS). Some of these proteins were further validated by co-precipitation experiments with rhZP and functional zona binding tests. main results and the role of chance: We identified proteins that are glycolytic enzymes such as pyruvate kinase 3, enolase 1, glyceraldehyde-3-phosphate dehydrogenase, aldolase A, triosephosphate isomerase, detoxification enzymes such as GSTM o