Interaction and translocation of cysteamine (mercaptoethylamine) with model membranes: a 15N-NMR and 1H-NMR study

Autor: François Berleur, G. Subra, Pierre-Antoine Bonnet, Jean-Pierre Chapat, J.-P. Fernandez, Catherine Lagoueyte, Marc Fatome, Vincent Roman, Florence Fauvelle, Jean-Claude Debouzy
Rok vydání: 1997
Předmět:
Zdroj: European Journal of Pharmaceutics and Biopharmaceutics. 43:73-81
ISSN: 0939-6411
Popis: We investigated by 15 N-NMR (nuclear magnetic resonance) spectroscopy the interactions of 15 N-labeled cysteamine ([ 15 N]mercaptoethylamine (MEA)), a radioprotecting aminothiol, with model membranes of egg yolk phosphatidylcholine (EPC) and phosphatidic acid (EPA). We prepared large unilamellar vesicles (LUVs) with a pH gradient between the intravesicular space and the bulk medium. Over the pH range from 4.8 to 8.1, the observations show a MEA incorporation into the vesicles. This result is consistent with a specific dissociation balance at the lipid-water interface. We carried out another 1 H-NMR experiment with unlabeled MEA in the presence of small unilamellar vesicles (SUVs). It revealed that the interactions of MEA within the hydrophobic core of the phospholipidic bilayer vary with external pH value over the range 4.0–7.1. Through these experiments, and others compiled from the literature, it was concluded that 15 N-NMR spectroscopy is particularly successful for transmembrane transport analysis.
Databáze: OpenAIRE