Radiation-induced fragmentation of cardiolipin in a model membrane.
OBJECTIVE
To obtain evidence for the possibility of free-radical fragmentation of cardiolipin under the action of ionizing radiation as measured by its aqueous dispersion from liposomes.


METHODS
Liposomes of tetramyristoylcardiolipin (TMCL) were exposed to gamma-rays from 60Co or 137Cs sources at doses between 1 and 24kGy. Fragmentation products were identified using thin-layer chromatography and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS).


RESULTS
Using MALDI-TOF MS and thin-layer chromatography, it was shown that gamma-irradiation of liposomes consisting of TMCL was accompanied by free-radical fragmentation of the lipid to form dimiristoylphosphatidic acid and dimiristoylphosphatidyl hydroxyacetone. The yields of dimiristoylphosphatidic acid were greater than those of dimiristoylphosphatidyl hydroxyacetone, and formation of the named compounds was inhibited by dissolved oxygen.


CONCLUSIONS
It is shown for the first time that on gamma-irradiation, cardiolipin can undergo free-radical fragmentation in its polar component.
Shadyro
O I
OI
Department of Chemistry, Belarussian State University, Skaryna av. 4, 220050 Minsk, Republic of Belarus. shadyro@open.by
Yurkova
I L
IL
Kisel
M A
MA
Brede
O
O
Arnhold
J
J
D002308:Cardiolipins / Q000528:radiation effects*; D002462:Cell Membrane / Q000528:radiation effects; D005609:Free Radicals / Q000528:radiation effects*; D005720:Gamma Rays / Q000009:adverse effects*; D008081:Liposomes / Q000528:radiation effects*; D008954:Models, Biological; D011830:Radiation Effects
D002308:Cardiolipins; D005609:Free Radicals; D008081:Liposomes