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Updated: Jan 29, 2026

High-throughput Nitrobenzoxadiazole-labeled Cholesterol Efflux Assay
Published on: January 7, 2019
A novel method for conjugating the terminal amine of peptide ligands to cholesterol: synthesis iRGD-cholesterol
Matthew G Fete1, Jamie L Betker2, Richard K Shoemaker3
1School of Pharmacy, Rueckert-Hartman College, Regis University, 3333 Regis Blvd, Denver, CO 80221 USA.
Aim:
Conventional conjugation reactions often involve the use of activated PEG as a linker, but concerns about PEG-mediated reduction in intracellular delivery and enhanced immunogenicity have generated interest in developing methods that eliminate the need for a PEG linker.
Materials & Methods:
Reaction conditions were identified that specifically couples the terminal amine of a cyclic iRGD peptide (CRGDRGPDC) to the hydroxyl moiety of cholesterol through a short carbamate linker.
Results & Conclusion:
Using this method for synthesizing iRGD-cholesterol, peptide ligands can be incorporated into lipid-based delivery systems, thereby eliminating concerns about adverse reactions to PEG. Toxicity and stability data indicate low toxicity and adequate serum stability at low ligand levels.
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