Pappalysin-1 (EC 3.4.24.79, insulin-like growth factor binding protein-4 protease, pregnancy-associated plasma protein-A) is an enzyme. This enzyme catalyses the following chemical reaction Pappalysin-1 (EC 3.4.24.79, insulin-like growth factor binding protein-4 protease, pregnancy-associated plasma protein-A) is an enzyme. This enzyme catalyses the following chemical reaction