Membrane‐mediated capillary electrophoresis: Interaction of cationic peptides with bicelles

Electrokinetic capillary chromatography is applied to determine the membrane affinity of peptides using both 1,2‐dihexanoyl‐ sn ‐glycero‐3‐phosphocholine (DHPC) micelles and DHPC/1,2‐dimyristoyl‐ sn ‐glycero‐3‐phosphocholine (DMPC) bicelles under controlled conditions. The effect of temperature and the bicelle q value in surface association with cationic peptides is studied. The cationic peptides selected have a well‐defined membrane structure (indolicidin), induced secondary structure (melittin, magainin 2), or do not possess classical secondary structure (atrial natriuretic peptide (ANP) 1‐28, 4‐28, 5‐27). Electrokinetic capillary chromatography facilitated by DMPC and DHPC additives provides a rapid means of estimating lipophilicity and screening for peptides that have membrane affinity.