Variant fatty acid-like molecules Conjugation, novel approaches for extending the stability of therapeutic peptides

Abstract

The multiple physiological properties of glucagon-like peptide-1 (GLP-1) make it a promising drug candidate for the treatment of type 2 diabetes. However, the in vivo half-life of GLP-1 is short due to rapid degradation by dipeptidyl peptidase-IV (DPP-IV) and renal clearance. The poor stability of GLP-1 has significantly limited its clinical utility; however, many studies are focused on extending its stability. Fatty acid conjugation is a traditional approach for extending the stability of therapeutic peptides because of the high binding affinity of human serum albumin for fatty acids. However, the conjugate requires a complex synthetic approach, usually involving Lys and occasionally involving a linker. In the current study, we conjugated the GLP-1 molecule with fatty acid derivatives to simplify the synthesis steps. Human serum albumin binding assays indicated that the retained carboxyl groups of the fatty acids helped maintain a tight affinity to HSA. The conjugation of fatty acid-like molecules improved the stability and increased the binding affinity of GLP-1 to HSA. The use of fatty acid-like molecules as conjugating components allowed variant conjugation positions and freed carboxyl groups for other potential uses. This may be a novel, long-acting strategy for the development of therapeutic peptides.

Glycation of human serum albumin impairs binding to the glucagon-like peptide-1 analogue liraglutide

“…Moreover, this position is located in an unstructured part of liraglutide far from the palmitoyl fatty acid (d > 40Å on the X-ray structure: PDB ID: 4APD) and does not influence the binding to albumin, as confirmed by ITC measurements (data not shown). Most previous studies on liraglutide and other fattyacid grafted GLP1 analogues focused on the measure of their binding to the GLP-1 receptor, but rarely on their interaction with albumin (43)(44)(45) corresponding to a dissociation constant in the nanomolar range (48). Thus, fatty-acid grafted peptides (detemir and liraglutide) bind weakly to albumin compared to free fatty acids.…”

Factors affecting the physical stability (aggregation) of peptide therapeutics

“…Lipidation/acylation of peptides is becoming increasingly important in the field of therapeutic peptides [140,141]. Inspired by endogenous lipidation processes, it has been shown to improve many properties of a peptide, particularly its ability to bind to human serum albumin increasing the half-life of the peptide in vivo dramatically and also enhancing its ability to permeate body tissues [140,141]. Current therapeutics which use this approach include liraglutide [142] (a lipidated form of GLP-1), and insulin detemir, a lipidated conjugate of insulin [143].…”

Lipidated Peptide Dendrimers Killing Multidrug-Resistant Bacteria

“…[36][37][38][39] Furthermore lipidation is often used to extend the circulation time of peptides in vivo by inducing binding to serum albumin, 40 which extends their circulation time as demonstrated for insulin 41 as well as for GLP-1 analogues. 42 Here we report how the addition of a fatty acid to the core of G2KL followed by a combinatorial sequence optimization led us to discover AMPD TNS18, which is only half the size of G3KL yet displays a broader antibacterial activity spectrum including not only Gram negative MDR strains of P. aeruginosa and A. baumannii, but also methicillin resistant Staphylococcus aureus (MRSA). By profiling with P. aeruginosa LPS deletion mutants we show that the added lipid chain is essential to confer activity.…”