May play a role in activating hydrolytic enzymes that are involved in the degradation of yolk proteins in developing embryos or may function as an exopeptidase in the degradation of vitellogenin. Synthesized in the fat body of vitellogenic females, secreted into the hemolymph and accumulates in yolk bodies of developing oocytes. Maximally present at the middle of embryonic development and disappears by the end. By 20-hydroxyecdysone. Belongs to the peptidase S10 family. Lacks the last active site residue.