Characterization of solvation properties of lipid bilayer membranes in liposome electrokinetic chromatography.
The nature of solute interactions with biomembrane-like liposomes, made of naturally occurring phospholipids and cholesterol, was characterized using electrokinetic chromatography (EKC). Liposomes were used as a pseudo-stationary phase in EKC that provided sites of interactions for uncharged solutes. The retention factors of uncharged solutes in liposome EKC are directly proportional to their liposome-water partition coefficients. Linear solvation energy relationship (LSER) models were developed to unravel the contributions from various types of interactions for solute partitioning into liposomes. Size and hydrogen bond acceptor strength of solutes are the main factors that determine partitioning into lipid bilayers. This falls within the general behavior of solute partitioning from an aqueous into organic phases such as octanol and micelles. However, there exist subtle differences in the solvation properties of liposomes as compared to those of octanol and various micellar pseudo-phases such as aggregates of sodium dodecyl sulfate (SDS), sodium cholate (SC), and tetradecylammonium bromide (TTAB). Among these phases, the SDS micelles are the least similar to the liposomes, while octanol, SC, and TTAB micelles exhibit closer solvation properties. Subsequently, higher correlations are observed between partitioning into liposomes and the latter three phases than that into SDS.
Burns
Scott T
ST
North Carolina State University, Department of Chemistry, Raleigh 27695-8204, USA.
Agbodjan
Armel A
AA
Khaledi
Morteza G
MG
D020374:Chromatography, Micellar Electrokinetic Capillary / Q000379:methods*; D008051:Lipid Bilayers; D008081:Liposomes; D008567:Membranes, Artificial; D008962:Models, Theoretical; D012995:Solubility
D008051:Lipid Bilayers; D008081:Liposomes; D008567:Membranes, Artificial