THU262 Improvement Of Pharmacokinetic Properties Of Vasoactive Intestinal Peptide Through Backbone Modifications

Abstract

Abstract Disclosure: M.S. Al Najar: None. A.M. Lipchik: None. Vasoactive Intestinal Peptide (VIP) is a 28 amino acid neuropeptide hormone that is a part of the glucagon/secretin family. VIP has myriad physiological functions, including incretin effects, immune modulation, corneal wound repairing, and lacrimal secretion. VIP executes these functions through activation of two B1 family of G-protein-coupled receptors, VPAC1 and VPAC2, leading to cAMP production. Previous research has demonstrated that VIP has immense therapeutic potential in treating many diseases including type 2 diabetes, cardiovascular disease, and autoimmune diseases such as rheumatoid arthritis, type 1 diabetes, and Crohn's disease. Although VIP has proven to be pharmacologically active in these diseases, its utility as a therapeutic is limited due to its short half-life in circulation (less than one minute) caused by proteolytic degradation. Previous efforts have been made to improve serum stability through peptide stapling using lactamization and olefin-metathesis. However, both strategies failed to increase the stability of VIP. Additional strategies are needed to improve serum stability of VIP. A potential alterative approach is the utilization of peptide backbone modifications to prevent proteolytic recognition and degradation. The introduction of unnatural amino acids and analogs such as N-methyl amino acids and peptoids into the VIP sequence alters the peptide bond by placement of a methyl group or a side chain on the amine. Here, we present a library of VIP analogs containing N-methyl amino acids and peptoid substitutions. The serum stability, structural conformation, and pharmacological activity of the VIP analog library was compared and tested against wild-type VIP. The incorporation of N-methyl amino acids or peptoid residues demonstrated significant improvement in stability in human serum. In addition, the VIP analogs maintained alpha-helical confirmation similar to wild-type VIP. Finally, the VIP analogs were shown to maintain pharmacological activity as VPAC1 agonist as measured by cAMP production and glucose-dependent insulin secretion. Together, these results display the incorporation of unnatural amino acids with modified backbones can improve pharmacokinetics while maintaining pharmacodynamics of VIP, allowing for the potential use of VIP as a therapeutic. Presentation: Thursday, June 15, 2023