title: Cholesterol-rich membrane coatings for interaction studies in capillary electrophoresis: application to red blood cell lipid extracts.
abstract: The purpose was to develop a stable biological membrane coating for CE useful for membrane interaction studies. The effect of cholesterol (chol) on the stability of dipalmitoylphosphatidylcholine (DPPC) and sphingomyelin (SM) coatings was studied. In addition, a fused-silica capillary for CE was coated with human red blood cell (RBC) ghost lipids. Liposomes prepared of DPPC/SM with and without chol or RBC ghost lipids were flushed through the capillary and the stability of the coating was measured electrophoretically. Similar mixtures of DPPC/SM with and without chol were further studied by differential scanning calorimetry. The presence of phosphatidylcholine as a basic component in the coating solution of DPPC/SM/chol was found to be essential to achieve a good and stable coating. The results also confirmed the stability of coatings obtained with solutions of DPPC with 0-30 mol% of chol and SM in different ratios, which more closely resemble natural membranes. Finally, the electrophoretic measurements revealed that a stable coating is formed when capillaries are coated with liposomes of RBC ghost lipids.
authors.affiliation: Laboratory of Analytical Chemistry, Department of Chemistry, University of Helsinki, Helsinki, Finland.
authors.forename: Maria V
authors.initials: MV
authors.lastname: Lindén
authors.forename: Juha M
authors.initials: JM
authors.lastname: Holopainen
authors.forename: Antti
authors.initials: A
authors.lastname: Laukkanen
authors.forename: Marja-Liisa
authors.initials: ML
authors.lastname: Riekkola
authors.forename: Susanne K
authors.initials: SK
authors.lastname: Wiedmer
mesh_terms: D015060:1,2-Dipalmitoylphosphatidylcholine / Q000737:chemistry; D019326:17-alpha-Hydroxyprogesterone / Q000302:isolation & purification; D000450:Aldosterone / Q000302:isolation & purification; D000735:Androstenedione / Q000302:isolation & purification; D002152:Calorimetry, Differential Scanning; D002784:Cholesterol / Q000737:chemistry; D053841:Electroosmosis; D019075:Electrophoresis, Capillary / Q000295:instrumentation / Q000379:methods*; D004910:Erythrocyte Membrane / Q000737:chemistry; D004912:Erythrocytes / Q000737:chemistry*; D008051:Lipid Bilayers / Q000737:chemistry; D008563:Membrane Lipids / Q000737:chemistry*; D008567:Membranes, Artificial; D011374:Progesterone; D013739:Testosterone / Q000302:isolation & purification
chemical_list: D008051:Lipid Bilayers; D008563:Membrane Lipids; D008567:Membranes, Artificial; D015060:1,2-Dipalmitoylphosphatidylcholine; D013739:Testosterone; D000735:Androstenedione; D000450:Aldosterone; D011374:Progesterone; D019326:17-alpha-Hydroxyprogesterone; D002784:Cholesterol