The researchers studied proteins on the surface of human sperm to understand their role in preparing sperm for fertilization. They analyzed 29 proteins and found that these proteins can slow down the process that helps sperm become ready to fertilize an egg. When sperm were exposed to these proteins, they showed changes in movement, protein changes, and reactions to certain chemicals. The proteins seemed to hinder the normal sperm preparation process, but some changes could be reversed. Understanding these proteins could help us grasp how they affect sperm function during fertilization.