Molecular interaction of zp3 to zp3r reveals a cross-species fertilization mechanism

Objective: To evaluate the role of ZP3R in the species-specific fertilization mechanism. Methods: ZP3/ZP3R protein sequences of Mus musculus, Rattus norvegicus, and Cavia porcellus were downloaded from UNIPROT. Percentage of amino acids that was calculated by using the SIAS program. Protein sequences modeled was established by using the Modeller 9.14 program and glycosylation of the ZP3 using GlyProt program. Docking simulation of the ZP3R-ZP3 was performed between the same species and different species with PatchDock program. Results: Comparison of the ZP3R and ZP3 structure between species showed that ZP3 in these three species was more similar than ZP3R. Docking simulations of protein showed that changes in the pattern of the ZP3-ZP3R domain for interaction on cross-species compared to the same species. Changes in the pattern of binding ZP3R-ZP3 made sperm-egg binding was not functional and could inhibit cross-fertilization. Conclusions: ZP3R-ZP3 interaction is species-specific, and the role of ZP3R is greater than ZP3 in determining the species-specific recognition stage and sperm-egg binding.