Identification of an ApoA-I Ligand Domain That Interacts with High-Affinity Binding Sites on HepG2 Cells
| Autor: | Corinne Rolland, Bertrand Perret, Didier Cachot, Hugues Chap, Xavier Collet, Ronald Barbaras, François Tercé, Anne Garcia, Valérie Georgeaud |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
Apolipoprotein B
Molecular Sequence Data Biophysics Peptide Ligands Binding Competitive Biochemistry Liver Neoplasms Experimental Tumor Cells Cultured Animals Humans Amino Acid Sequence Binding site Molecular Biology chemistry.chemical_classification Binding Sites Apolipoprotein A-I biology Ligand binding assay nutritional and metabolic diseases Cooperative binding Cell Biology Ligand (biochemistry) Peptide Fragments Protein Structure Tertiary Amino acid Kinetics chemistry biology.protein lipids (amino acids peptides and proteins) Lipoproteins HDL Binding domain |
| Zdroj: | Biochemical and Biophysical Research Communications. 267:541-545 |
| ISSN: | 0006-291X |
| Popis: | We have previously described the presence of two (high- and low-affinity) HDL binding sites on the hepatoma cell line (HepG2) (R. Barbaras, X. Collet, H. Chap, and B. Perret (1994) Biochemistry 33, 2335-2340]. Moreover, apoA-I, the major HDL apolipoprotein, interacts with these two binding sites, while lipid-free apoA-I binds only to the high-affinity sites. Using tryptic HDL fragments and HepG2 cell monolayers as an "affinity matrix," we identified an apoA-I peptide of 16 amino acids, spanning between residues 62 and 77, as a ligand domain. The corresponding synthetic peptide displays high-affinity (K(d) approximately 10(-7) M) and low-capacity (B(max) 8 pmol/mg of cell protein) binding components. Competition experiments with this peptide, using (125)I-labeled free apoA-I as a ligand, show that this binding corresponds to the high-affinity binding sites already described. In conclusion, we identified the apoA-I 62-77 region as a specific high-affinity ligand domain of HDL on HepG2 cells. |
| Databáze: | OpenAIRE |
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