Preferential cleavage at the carboxyl of hydrophobic amino acids, but fails to cleave 15-Leu-|-Tyr-16, 16-Tyr-|-Leu-17 and 24-Phe-|-Phe-25 of insulin B chain. Activates trypsinogen, and degrades keratin. O-glycosylated. Belongs to the peptidase A1 family.