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Updated: Aug 8, 2026

Automated Acoustic Dispensing for the Serial Dilution of Peptide Agonists in Potency Determination Assays
Published on: November 10, 2016
Disconnect between signalling potency and in vivo efficacy of pharmacokinetically optimised biased glucagon-like
Maria Lucey1, Philip Pickford1, Stavroula Bitsi2
1Section of Investigative Medicine, Imperial College London, London W12 0NN, United Kingdom.
Objective:
The objective of this study was to determine how pharmacokinetically advantageous acylation impacts on glucagon-like peptide-1 receptor (GLP-1R) signal bias, trafficking, anti-hyperglycaemic efficacy, and appetite suppression.
Methods:
In vitro signalling responses were measured using biochemical and biosensor assays. GLP-1R trafficking was determined by confocal microscopy and diffusion-enhanced resonance energy transfer. Pharmacokinetics, glucoregulatory effects, and appetite suppression were measured in acute, sub-chronic, and chronic settings in mice.
Results:
A C-terminally acylated ligand, [F1,G40,K41.C16 diacid]exendin-4, was identified that showed undetectable β-arrestin recruitment and GLP-1R internalisation. Depending on the cellular system used, this molecule was up to 1000-fold less potent than the comparator [D3,G40,K41.C16 diacid]exendin-4 for cyclic AMP signalling, yet was considerably more effective in vivo, particularly for glucose regulation.
Conclusions:
C-terminal acylation of biased GLP-1R agonists increases their degree of signal bias in favour of cAMP production and improves their therapeutic potential.
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