Interactions of Lecithin and Pig Apolipoproteins of High Density Lipoproteins at the Surface Monolayer of Reconstituted Very Small Particles

• Published in: Chemical & pharmaceutical bulletin Vol. 38; no. 8; pp. 2079 - 2082
• Main Authors: HANDA, Tetsurou, KOMATSU, Hiroaki, KAKEE, Atsuyuki, MIYAJIMA, Koichiro
• Format: Journal Article
• Language: English
• Published: Tokyo The Pharmaceutical Society of Japan 1990; Maruzen; Japan Science and Technology Agency
• Subjects: amphipathic helix; Analytical, structural and metabolic biochemistry; Animals; apolipoprotein; Apolipoproteins A - chemistry; Biological and medical sciences; egg yolk lecithin monolayer; Fluorescent Dyes - chemistry; Fundamental and applied biological sciences. Psychology; high density lipoprotein; hydrophobic binding probe; Lipoproteins, HDL - chemistry; Lipoproteins, myelin; Microspheres; Naphthalenesulfonates - chemistry; Particle Size; Phosphatidylcholines - chemistry; Proteins; reconstituted high density lipoprotein; Surface Properties; Swine; Triolein - chemistry; Monolayer; Sonication; Lecithin; Gel electrophoresis; Apolipoproteins; Association isotherm; Pig; Vertebrata; Mammalia; Reconstituted system; Molecular probe; Artiodactyla; Lipoprotein HDL; Ungulata
• ISSN: 0009-2363; 1347-5223
• DOI: 10.1248/cpb.38.2079

Cosonication of egg yolk lecithin and triolein with apolipoproteins isolated from pig high density lipoprotein (apoHDL) gave us reconstituted high density lipoprotein particles (r-HDLs) of 9 nm in average diameter. They were smaller than microemulsion particles (MEs) composed of the lipids (35 nm). The protein/ egg yolk lecithin ratio in the fractionated r-HDLs was higher in the smaller particles. Binding of a hydrophobic probe, 2-p-toluidinylnaphthalene-6-sulfonate (TNS), to MEs, r-HDLs and apoHDL were evaluated on the basis of Halfman and Nishida's method. The reconstitution of apoHDL into MEs led to a 68% reduction in the binding of TNS and a small increase in the α-helix content as compared with free apoHDL. The binding experiments also showed the condensation of lecithin molecules at the r-HDL surface. The amphipathic helixes of apoHDL are located in the surface monolayer of egg yolk lecithin surrounding the triolein core. The intercalation of the hydrophobic residues of apoHDL between egg yolk lecithin molecules brings about a pronounced curvature of the surface and a decrease in the particle diametri.