Chemistry and Physics Faculty Articles
Title
Locating Intercalants Within Lipid Bilayers Using Fluorescence Quenching by Bromophospholipids and Iodophospholipids
Document Type
Article
Publication Date
7-2019
Publication Title
Chemistry and Physics of Lipids
Keywords
DMPC liposomes, Bioliposomes, Erythrocyte ghosts, Bromophospholipid, Iodophospholipid, Fluorescence quenching, Intercalant depth, Porphyrins
ISSN
0009-3084
Volume
221
First Page
128
Last Page
139
Abstract
In previous work, we have been able to determine the depth of intercalated molecules within the lipid bilayer using the solvent polarity sensitivity of three spectroscopic techniques: the 13C NMR chemical shift (δ); the fluorescence emission wavelength (λem), and the ESR β-H splitting constants (aβ-H). In the present paper, we use the quenching by a heavy atom (Br or I), situated at a known location along a phospholipid chain, as a probe of the location of a fluorescent moiety. We have synthesized various phospholipids with bromine (or iodine) atoms substituted at various locations along the lipid chain. The latter halolipids were intercalated in turn with various fluorophores into DMPC liposomes, biomembranes and erythrocyte ghosts. The most effective fluorescence quenching occurs when the heavy atom location corresponds to that of the fluorophore. The results show that generally speaking the fluorophore intercalates the same depth independent of which lipid bilayer is used. KBr (or KI) is the most effective quencher when the fluorophore resides in or at the aqueous phase. Presumably because of iodine's larger radius and spin coupling constant, the iodine analogs are far less discriminating in the depth range it quenches.
NSUWorks Citation
Alexenberg, C., Afri, M., Eliyahu, S., Porat, H., Ranz, A., & Frimer, A. A. (2019). Locating Intercalants Within Lipid Bilayers Using Fluorescence Quenching by Bromophospholipids and Iodophospholipids. Chemistry and Physics of Lipids, 221, 128 - 139. https://doi.org/10.1016/j.chemphyslip.2019.03.018. Retrieved from https://nsuworks.nova.edu/cnso_chemphys_facarticles/269
DOI
10.1016/j.chemphyslip.2019.03.018
Comments
©2019 Published by Elsevier B.V.