Description Analysis Note Optimum pH is 2-4. Active in 4 M urea and 3 M guanidine HCl. Stable at 60 °C. Pepsin is irreversibly inactivated at pH>6. E1%/280=14.7 Application Used to produce F(ab′)2 fragments of antibodies. Biochem/physiol Actions Preferential cleavage: hydrophobic and aromatic residues in P1 and P1′ postitions. Cleaves Phe-Val, Gln-His, Glu-Ala, Ala-Leu, Leu-Tyr, Tyr-Leu, Gly-Phe, Phe-Phe and Phe-Tyr bonds in the β chain of insulin Other Notes Sales restrictions may apply