Liposome Click Membrane Permeability Assay for Identifying Permeable Peptides

Area of Science:

• Biochemistry
• Nanotechnology
• Drug Delivery

Background:

• Assessing peptide membrane permeability is crucial for drug development.
• Existing methods may lack target agnostic capabilities or fail to fully represent intracellular barriers.

Purpose of the Study:

• To develop a novel, target-agnostic liposome click membrane permeability assay (LCMPA).
• To utilize liposomes encapsulating dibenzo cyclooctyne biotin (DBCO-Biotin) for conjugating azido-modified peptides.
• To assess peptide translocation from the extravesicular space into the liposome lumen.

Main Methods:

• DBCO-Biotin liposomes were prepared using egg phosphatidylcholine and cholesterol via lipid film rehydration, freeze/thaw, and extrusion.
• Liposome size was characterized using dynamic light scattering.
• Peptide permeability was assessed by measuring biotinylation within the liposomes.

Main Results:

• The LCMPA demonstrated higher biotinylation for permeable peptides, indicative of energy-independent transport mechanisms.
• Results from LCMPA showed a strong correlation with shifts in peptide potency observed in cellular versus biochemical assays.
• The assay effectively quantified peptide permeability across the intracellular barrier in intact cells.

Conclusions:

• A novel membrane permeability assay, LCMPA, has been developed.
• The assay has significant potential for evaluating the energy-independent transport of diverse peptides.
• LCMPA offers a valuable tool for understanding peptide behavior across biological barriers.