High density lipoprotein binding protein of eel (Anguilla japonica) liver with specificity of binding to apoAI as a ligand.
High-density lipoprotein (HDL) binding protein (HBP) was isolated from the microsomal fraction of eel liver homogenate by affinity chromatography with a HDL-column. After SDS-PAGE and blotting, HBP on the PVDF membrane was detected by FITC-labeled HDL and apolipoprotein AI (apoAI) as a ligand. HBP in the microsomal fraction was most abundant among microsomal, mitochondrial and cytosolic fractions. The HBP isolated by a HDL-column consisted of at least three proteins with low molecular weights of 18.5, 14.5 and 13.5 kDa; the main component was 14.5 kDa. These proteins are not products of protease digestion, as the procedure was carried out in the presence of protease inhibitors including (p-aminophenyl) methansulfonyl fluoride, 4-(2-aminoethyl)-benzenesulfonyl fluoride, pepstatin A, E-64, bestatin, leupeptin, aprotinin and EDTA. The HBP specifically bound to FITC-apoAI and faintly bound or did not bind to FITC-apoAII. Furthermore, binding of HDL labeled with lipophilic fluorescence to isolated eel hepatocytes was inhibited by the antibody to apoAI, but not inhibited by the antibody to apolipoprotein AII (apoAII). These results strongly suggest that the HBP isolated from the microsomal fraction is present on the plasma membrane of eel liver and plays important roles for the lipid transport through the interaction with HDL.
Katoh
H
H
The United Graduate School of Agricultural Science, Kagoshima University, 890-0056, Kagoshima, Japan.
Ping Ge
Y
Y
Tsuda
T
T
Hayashi
S
S
D000818:Animals; D016632:Apolipoprotein A-I / Q000737:chemistry*; D002846:Chromatography, Affinity; D003600:Cytosol / Q000378:metabolism; D004524:Eels; D005434:Flow Cytometry; D016650:Fluorescein-5-isothiocyanate / Q000737:chemistry; D005456:Fluorescent Dyes / Q000494:pharmacology; D005782:Gels / Q000494:pharmacology; D022781:Hepatocytes / Q000378:metabolism; D008024:Ligands; D050356:Lipid Metabolism; D008075:Lipoproteins, HDL / Q000737:chemistry*; D008099:Liver / Q000737:chemistry*; D008862:Microsomes, Liver / Q000737:chemistry / Q000378:metabolism; D011108:Polymers / Q000494:pharmacology; D011485:Protein Binding; D011726:Pyridinium Compounds / Q000494:pharmacology
D016632:Apolipoprotein A-I; D005456:Fluorescent Dyes; D005782:Gels; D008024:Ligands; D008075:Lipoproteins, HDL; D011108:Polymers; D011726:Pyridinium Compounds; C062163:TSKgel Tresyl-Toyopearl 650M; C070657:N,N-dipentadecylaminostyrylpyridinium; D016650:Fluorescein-5-isothiocyanate