The peptide region containing residues 390-404 in Activated Protein C (APC) is essential for anticoagulant activity and is available for interaction with antibodies or with other proteins, such as the macromolecular substrates Factors Va or VIIIa. APC regulates blood coagulation by proteolytic inactivation of the blood coagulation cofactors Va and VIIIa.

Highly potent integrin α1β1 inhibitor (IC50 = 0.8 nM for α1β1 binding to type IV collagen). Selective for α1β1 over α2β1, αIIbβ3, αvβ3, α4β1, α5β6, α9β1 and α4β7. Inhibits FGF2-stimulated angiogenesis in the chicken chorioallantoic model. Displays antitumor efficacy in a synergistic mouse model of Lewis lung carcinoma; blocks human melanoma growth in nude mice.

PACAP (1-38), a novel neuropeptide isolated from the bovine hypothalamus is more active than vasoactive intestinal peptide (VIP) in stimulating adenylate cyclase (EC50=7 nM). PACAP 1-38 (10-9 M) increased substance P (SP), gastrin releasing peptide (GRP), and VIP release. PACAP 1-38 (10-8 M) inhibited gastrin secretion and stimulated somatostatin secretion and motility dose-dependently.