The binding of human serum transferrin to its specific receptor reconstituted into liposomes
Autor: | Anna Maria D'Alessandro, Angela Impagnatiello, Gabriele D'Andrea, Antonio Di Giulio, Arduino Oratore, Maria A. Saletti |
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Rok vydání: | 1994 |
Předmět: |
chemistry.chemical_classification
Liposome Placenta Ligand binding assay Transferrin Transferrin receptor Cell Biology Phosphatidic acid Binding Competitive Chromatography Affinity chemistry.chemical_compound Biochemistry chemistry Affinity chromatography Immunoglobulin G Phosphatidylcholine Liposomes Receptors Transferrin Phosphatidylcholines Animals Humans Female Rabbits Receptor |
Zdroj: | Cellular Signalling. 6:83-90 |
ISSN: | 0898-6568 |
DOI: | 10.1016/0898-6568(94)90063-9 |
Popis: | Human placental transferrin receptor (HPTR), purified following a procedure based on affinity chromatography step, was reconstituted by the detergent dialysis method into various kinds of phosphatidylcholine vesicles and the receptor ability to bind 125I-labelled human serum transferrin (HST) was then evaluated. In our experimental conditions, the binding of the labelled protein to its specific receptor showed several features, in particular: (1) in cholesterol/1-alpha-dipalmitoylphosphatidyl choline (CHO/DPPC) liposomes, a positive cooperatively of the transferrin binding resulted at the lowest cholesterol/phospholipids (C/P) ratio; 1-alpha-dioleylphosphatidyl choline (DOPC) and phosphatidic acid (PA) containing liposomes showed an opposite binding curve trend; (2) the apparent dissociation constant (K'd) did not change significantly as a function of the lipid composition, being always around 1.00 x 10(-6) M; (3) the encapsulation capacity of liposomes decreased from 27% to about 13% with increasing amounts of cholesterol and was around 20% in the presence of DOPC or PA; about 8-13% of this receptor was found to be functional; (4) receptor-loaded liposomes treated with polyclonal anti-HPTR rabbit antibodies showed a remarkable binding decrease for transferin. All these results seem to point out the crucial role played by the environment in the binding behaviour of the transferrin receptor. |
Databáze: | OpenAIRE |
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