Enzyme replacement therapy in porphyrias-II: Entrapment of δ-aminolaevulinate dehydratase in liposomes
1. 1. Different types of neutral and negative, large, small and multilamellar liposomes were prepared and conditions for entrapping partially and highly purified preparations of blood and bovine ALA-dehydratase were studied. 2. 2. Gel filtration on Sepharose 4B, resolved liposomes formed in the abse...
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| Autores principales: | , , , |
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| Formato: | JOUR |
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| Acceso en línea: | http://hdl.handle.net/20.500.12110/paper_0020711X_v15_n3_p439_Espinola |
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| Sumario: | 1. 1. Different types of neutral and negative, large, small and multilamellar liposomes were prepared and conditions for entrapping partially and highly purified preparations of blood and bovine ALA-dehydratase were studied. 2. 2. Gel filtration on Sepharose 4B, resolved liposomes formed in the absence of enzyme from free enzyme, when both were chromatographed 1-2 hr after mixing, showing that ALA-D did not become associated with liposomes. 3. 3. Preparation of liposomes in the presence of ALA-D resulted in partial entrapment of the enzyme and separation of the protein-containing liposomes from excess free protein was achieved by Sepharose 4B gel filtration. 4. 4. Part of the activity of ALA-D associated with liposomes was latent, and it could only be detected after treatment with Triton X-100, which, at the concentration used, disrupted the spherules and did not affect ALA-D activity. Some activity was also measured in intact ALA-D loaded liposomes. 5. 5. Of all preparations of liposomes, best entrapment values for ALA-D were consistently obtained with negatively charged large multilamellar vesicles, (-LMV (ALA-D)). Considerable less yield was associated with negative small unilamellar vesicles (-SUV) and neutral large unilamellar vesicles (nLUV). © 1983. |
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