本酶催化的反应为Hydrolysis Of Proteins With Specificity Similar To That Of Pepsin A; Prefers Hydrophobic Residues At P1 And P1', But Does Not Cleave Ala14-Leu In The B Chain Of Insulin Or Z-Glu-Tyr. Clots Milk,来自子囊菌寄生内座壳(Endothia parasitica)。属于肽酶家族A1(胃蛋白酶A家族)。