3.4.23.29 Milk clotting activity, broad specificity, but fails to cleave Leu15-Tyr or Tyr16-Leu of insulin B chain - - 3.4.23.29 Milk clotting activity, broad specificity, but fails to cleave Leu15-Tyr or Tyr16-Leu of insulin B chain catalytic mechanism, transition state model, substrate binding structure and mechanism 669833