Behavior of the DPH fluorescence probe in membranes perturbed by drugs

0517124 - ÚFCH JH 2020 RIV IE eng J - Journal Article
Poojari, C. - Wilkosz, N. - Lira, R. B. - Dimova, R. - Jurkiewicz, Piotr - Petka, R. - Kepczynski, M. - Róg, T.
Behavior of the DPH fluorescence probe in membranes perturbed by drugs.
Chemistry and Physics of Lipids. Roč. 223, SEP 2019 (2019), č. článku 104784. ISSN 0009-3084. E-ISSN 1873-2941
Institutional support: RVO:61388955
Keywords : particle mesh ewald * aa force-field * biophysical properties * model membranes * lipid-membranes * staphylococcus-aureus * unilamellar vesicles * cholesterol * dynamics * dppc * 1,6-diphenyl-1,3,5-hexatriene * Lipid bilayers * Molecular dynamics simulations * Fluorescence anisotropy
OECD category: Physical chemistry
Impact factor: 2.094, year: 2019
Method of publishing: Open access

1,6-Diphenyl-1,3,5-hexatriene (DPH) is one of the most commonly used fluorescent probes to study dynamical and structural properties of lipid bilayers and cellular membranes via measuring steady-state or time-resolved fluorescence anisotropy. In this study, we present a limitation in the use of DPH to predict the order of lipid acyl chains when the lipid bilayer is doped with itraconazole (ITZ), an antifungal drug. Our steady-state fluorescence anisotropy measurements showed a significant decrease in fluorescence anisotropy of DPH embedded in the ITZ-containing membrane, suggesting a substantial increase in membrane fluidity, which indirectly indicates a decrease in the order of the hydrocarbon chains. This result or its interpretation is in disagreement with the fluorescence recovery after photobleaching measurements and molecular dynamics (MD) simulation data. The results of these experiments and calculations indicate an increase in the hydrocarbon chain order. The MD simulations of the bilayer containing both ITZ and DPH provide explanations for these observations. Apparently, in the presence of the drug, the DPH molecules are pushed deeper into the hydrophobic membrane core below the lipid double bonds, and the probe predominately adopts the orientation of the ITZ molecules that is parallel to the membrane surface, instead of orienting parallel to the lipid acyl chains. For this reason, DPH anisotropy provides information related to the less ordered central region of the membrane rather than reporting the properties of the upper segments of the lipid acyl chains.
Permanent Link: http://hdl.handle.net/11104/0302414