[The effect of holotoxin A1 on transport of calcium ions across the lipid models of biological membranes].
Planar bilayer lipid membranes formed from trepang phospholipids possess an intrinsic Ca2(+)-permeability. These phospholipids dissolved in a non-polar solvent can extract 45Ca2+ from the aqueous to the organic phase. The triterpenic glycoside holotoxin A isolated from the trepang Stichopus japonicus inhibits the Ca2+ flux of lipid bilayers from trepang phospholipids as well as the Ca2+ flux induced in phosphatidylcholine bilayers by the calcium ionophore X-537A. Toxin inhibits the Ca2+ ionophore A23187 induced Ca2+ efflux from phosphatidylcholine liposomes and 45Ca2+ transition from the aqueous to the organic phase. Holotoxin A does not inhibit the 45Ca2+ transfer to the non-polar phase induced by holoturia phospholipids and does not affect the phosphatidylcholine hydroperoxide-induced Ca2+ flux of lipid bilayers. Using the fluorescent probe pyrene, it was demonstrated that toxin increases the microviscosity of liposomal membranes and trepang oocyte "ghosts".
Aminin
D L
DL
Lebedev
A V
AV
Levitskiĭ
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DO
D000818:Animals; D000001:Calcimycin / Q000494:pharmacology; D002121:Calcium Channel Blockers / Q000494:pharmacology; D015220:Calcium Channels / Q000187:drug effects / Q000378:metabolism*; D006027:Glycosides / Q000494:pharmacology*; D008051:Lipid Bilayers / Q000378:metabolism*; D008564:Membrane Potentials / Q000187:drug effects; D010539:Permeability; D010743:Phospholipids; D012616:Sea Cucumbers; D014315:Triterpenes / Q000494:pharmacology*
D002121:Calcium Channel Blockers; D015220:Calcium Channels; D006027:Glycosides; D008051:Lipid Bilayers; D010743:Phospholipids; D014315:Triterpenes; C001883:stichoposide; D000001:Calcimycin
Vliianie golotoksina A1 na perenos ionov kal'tsiia cherez lipidnye modeli biologicheskikh membran.