A drug-lipid interaction model: atropine induces interdigitated bilayer structure.
X-ray diffraction and fluorescence methods have been carried out to examine the effects of a drug, atropine, on the structure of model membranes: dipalmitoylphosphatidylglycerol(DPPG) multilamella vesicles(MLVs). A structural analysis by small angle x-ray diffraction shows that, with incorporation of atropine, the lamella repeating period of DPPG MLV is decreased from 5.89 nm to 4.52 nm. Using fluorescence probe 1,6-diphenyl-1,3,5-hexatriene(DPH) we find that the fluorescence intensity of DPH reduces largely at a narrow scope of atropine concentration. The experiments of fluorescence polarization of n-(9-anthroyloxyl)-stearic acid (nAS) and 16-(9-anthroyloxyl)-palmiticacid (16AP) discover that the normal polarization gradient almost disappears in DPPG/atropine system. By colligating the above results, we can draw a conclusion that atropine induces the transition from non-interdigitated to interdigitated stricture of DPPG vesicles in gel phase, which provides a sound model of drug-lipid interaction.
Hao
Y H
YH
National Laboratory of Biomacromolecules, Institute of Biophysics, Academy Sinica, Beijing, China.
Xu
Y M
YM
Chen
J W
JW
Huang
F
F
D001285:Atropine / Q000494:pharmacology*; D004161:Diphenylhexatriene / Q000378:metabolism; D005454:Fluorescence Polarization; D005456:Fluorescent Dyes / Q000378:metabolism; D008051:Lipid Bilayers / Q000737:chemistry*; D008081:Liposomes / Q000737:chemistry; D010169:Palmitic Acids / Q000378:metabolism; D010715:Phosphatidylglycerols / Q000737:chemistry; D013229:Stearic Acids / Q000378:metabolism; D014961:X-Ray Diffraction
D005456:Fluorescent Dyes; D008051:Lipid Bilayers; D008081:Liposomes; D010169:Palmitic Acids; D010715:Phosphatidylglycerols; D013229:Stearic Acids; D004161:Diphenylhexatriene; D001285:Atropine; C030345:1,2-dipalmitoylphosphatidylglycerol