Recombinant models of lipoproteins. Apolipoprotein A-I/phosphatidylcholine/cholesterol complexes formed in a 2-chloroethanol-water mixture.
Apolipoprotein A-I can spontaneously associate with phosphatidylcholine and cholesterol in 2-chloroethanol-water mixture. It was demonstrated, using a spin label technique, that dissolved molecules participate in complex formation. The apolipoprotein A-I/phosphatidylcholine/cholesterol complexes were isolated by gel chromatography. Complexes of three types were prepared and characterized: type A, large heterogeneous aggregates with molecular weight 600 000, sedimentation coefficient 10 S and the following molar composition - protein/phosphatidylcholine/cholesterol, 1:(70-100):(10-12); types B and C, with weight average molecular weights 140 000 and 110 000, average sedimentation coefficients 3.6 S and 1.7 S, respectively. Both types have the same molar composition - protein/phosphatidylcholine/cholesterol, 1:25:8. The dissimilar sedimentation coefficients between complexes B and C may be explained by the difference in the monomer/tetramer ratio (monomer molecular weight 50 000). The spin label sn-1-O-stearoyl-2-O-9'-spiro(4'',4''-dimethyloxazolidine-3''-oxyl) heptadecanoylglycero-3-phosphocholine introduced into the complexes A and B showed different thermal properties of these complexes, which may be due to differences in the lipid-protein interactions.
Antonov
I V
IV
Medvedeva
N V
NV
Misharin AJu
Morozkin
A D
AD
Ruuge
E K
EK
D016632:Apolipoprotein A-I; D001054:Apolipoproteins A; D055598:Chemical Phenomena; D002621:Chemistry; D002784:Cholesterol; D002850:Chromatography, Gel; D004578:Electron Spin Resonance Spectroscopy; D005023:Ethylene Chlorohydrin; D006801:Humans; D008970:Molecular Weight; D010713:Phosphatidylcholines; D013696:Temperature; D014867:Water
D016632:Apolipoprotein A-I; D001054:Apolipoproteins A; D010713:Phosphatidylcholines; D014867:Water; D005023:Ethylene Chlorohydrin; D002784:Cholesterol