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Electron spin resonance study on the permeability of superoxide radicals in lipid bilayers and biological membranes
Author(s) -
Mao Guo Dong,
Poznansky Mark J.
Publication year - 1992
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(92)80675-7
Subject(s) - radical , electron paramagnetic resonance , membrane , lipid bilayer , chemistry , superoxide , biological membrane , photochemistry , biophysics , permeability (electromagnetism) , nuclear magnetic resonance , biochemistry , biology , physics , enzyme
The permeability of lipid bilayers and biological membranes to superoxide free radicals was examined by using superoxide dismutase (SOD)‐loaded lipid vesicles and SOD‐loaded erythrocyte ghosts. After exposing SOD lipid vesicles and SOD ghosts to enzymatically produced superoxide radicals and using spin‐trapping and electron spin resonance (ESR) techniques, we found that SOD entrapped within erythrocyte ghosts effectively scavenges external O .− 2 while SOD inside the lipid bilayers has no effect. These results confirm that O .− 2 is able to cross through a biological plasma membrane but not across a pure lipid bilayer. The data provide instruction as to how and where anti‐oxidant therapy is to be approached relative to the site of oxygen free radical production.