EFFECT OF AMINO-ACIDS AND POLYPEPTIDES ON ELECTROKINETIC PROPERTIES OF PURE LIPID VESICLES AND MIXED VESICLES WITH CROWN ETHERS

Electrophoretic mobilities of phospholipid vesicles and mixed vesicles of phospholipid with a crown ether compound have been studied in the presence of amino acids (glutamic acid, lysine, and alanine) or polypeptides. L-lysine has a minor effect on the electrophoretic mobilities, in contrast to L-glutamic acid, which has a peculiar effect on the electrophoretic mobilities. Poly-L-glutamic acid and poly-L-lysine have a strong affinity for phosphatidylcholine vesicles and also for the mixed vesicles, which results in a significant charge effect on the electrophoretic mobilities. The presence of the crown ether ring on the vesicle surface causes not only selective binding effect for the −NH+3 group of amino acid residues but also a hydration effect which brings the vesicle surface to a more hydrophilic nature. © 1993 by Academic Press, Inc.