The rate of uptake and efflux of phosphatidylcholine from human erythrocytes depends on the fatty acyl composition of the exchanging species
| Autor: | F A, Kuypers, X, Andriesse, P, Child, B, Roelofsen, J A, Op den Kamp, L L, van Deenen |
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| Rok vydání: | 1986 |
| Předmět: |
Erythrocytes
Kinetics Biophysics Phospholipid Phosphatidylethanolamine Binding Protein Models Biological Biochemistry Androgen-Binding Protein Structure-Activity Relationship chemistry.chemical_compound Phospholipid transfer protein Phosphatidylcholine medicine Humans Phospholipid Transfer Proteins Vesicle Erythrocyte Membrane Biological Transport Cell Biology Red blood cell medicine.anatomical_structure chemistry Dipalmitoylphosphatidylcholine Phosphatidylcholines Composition (visual arts) Carrier Proteins |
| Zdroj: | Biochimica et Biophysica Acta (BBA) - Biomembranes. 857:75-84 |
| ISSN: | 0005-2736 |
| DOI: | 10.1016/0005-2736(86)90100-8 |
| Popis: | The rate of uptake of radioactive phosphatidylcholine molecules of different fatty acid composition in intact erythrocytes as facilitated by a phosphatidylcholine-specific transfer protein has been studied. When trace amounts of radiolabeled phosphatidylcholine molecules are present in donor vesicles consisting of egg phosphatidylcholine and cholesterol, the transfer of the radiolabeled species depends strongly on their fatty acyl composition: dipalmitoylphosphatidylcholine is transferred at the lowest rate, 1-saturated-2-unsaturated species are transferred faster and the highest rate is observed for dioleoyl phosphatidylcholine. Transfer of the various phosphatidylcholine molecules was measured furthermore using donor systems in which the bulk phosphatidylcholine was varied in its fatty acyl composition. Also in this type of experiment, the transfer protein preferentially stimulated transfer of unsaturated phosphatidylcholine molecules, especially from an environment containing more saturated molecules. Finally, the efflux of labeled phosphatidylcholine from intact erythrocytes to plasma in the absence of the phosphatidylcholine-specific transfer protein was studied and it became clear that in this case the nature of the effused molecules itself, rather than the composition of the bulk lipids, determined the effuse rates. An important conclusion to be drawn from these experiments is that radiolabeled phosphatidylcholine molecules, when used as markers for phospholipid exchange or transfer, should resemble in their fatty acid composition the composition of the bulk lipid in order to provide reliable data on rates and extents of the process studied. |
| Databáze: | OpenAIRE |
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