Poster Presentation 13th Australian Peptide Conference 2019

Development and optimization of GLP-1 analogs with improved drug delivery characteristics through conjugation to other molecules using Copper(I)-catalysed azide-alkyne cycloaddition (CuAAC) chemistry (#102)

Seyed Ebrahim Alavi 1 , Peter Moyle 1 , Peter John Cabot 1
  1. School of Pharmacy, The University of Queensland, Woolloongabba, 4102, Australia

Introduction: The ability of glucagon-like peptide 1 (GLP-1) to increase insulin secretion and inhibit glucagon release during hyperglycaemia causes GLP-1 to be considered as a promising agent for the treatment of type 2 diabetes mellitus (T2DM). However, rapid degradation of native GLP-1 (GLP-1(7-36)-NH2) by dipeptidyl peptidase‐4 (DPP4) enzyme and its rapid clearance from the kidney, due to low molecular weight (MW), limit GLP-1 clinical application [1].

Therefore, approaches to improve GLP-1 resistance against DPP4 and reduce its renal clearance are demanded to enhance GLP-1 therapeutic effects. Our work aims to develop the methods to enhance GLP-1 resistance against DPP4 and reduce its renal clearance, while these modifications preserve GLP-1 biological activity.

Methods: Various alkyne modified GLP-1 analogs were developed and site specifically conjugated to different azide components carriers using azide-alkyne copper(I)-catalysed azide-alkyne cycloaddition (CuAAC) chemistry. Also, the effects of these modifications were evaluated for activity (EC50) against the human GLP-1 (hGLP-1) receptor, and their stability toward proteolysis. The cell viability of native GLP-1 and modified GLP-1 analogs were evaluated using MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) assay on PC-3 and HEK-293 cell lines.

Results: The results showed that these modifications improved the resistance of alkyne modified GLP-1 analogs against DPP4 degradation. Also, the results of agonist activity assessment showed that alkyne modified GLP-1 at position 26 and N-terminal alkyne modified GLP-1 had similar and minimal effect on potency compared to C-terminal alkyne modified GLP-1 and GLP-1(7-36;A8G). The results of cell viability showed that the synthesized analogs had no toxicity on the cells.

Conclusion: The findings of this study showed that the conjugation of alkyne modified GLP-1 analogs to azide component using azide-alkyne CuAAC chemistry is a promising approach to develop GLP-1 analogs with improved drug delivery characteristics, improved resistance against DPP4, increased MW, and approximately similar biological activity to native GLP-1.

  1. Bukrinski JT, Sønderby P, Antunes F, Andersen B, Schmidt EG, Peters GH, Harris P. Glucagon-like Peptide 1 Conjugated to Recombinant Human Serum Albumin Variants with Modified Neonatal Fc Receptor Binding Properties. Impact on Molecular Structure and Half-Life. Biochemistry. 2017 Aug 25;56(36):4860-70.