Physicochemical characteristics of interaction of toxic triterpene glycosides from holothurians with rat brain Na+-K+-ATPase.
High-angle X-ray diffraction spectra showed that triterpene glycosides form crystalline complexes with membrane cholesterol. Electron microscopy demonstrated a decreased vesicle size, of the membrane preparation from rat brain which is enriched in Na+-K+-ATPase, by the triterpene glycosides. The Arrhenius plot was linear in the presence of triterpene glycosides. The half-width of the phosphatidylcholine N-methyl proton line in proton NMR spectra was not altered in the presence of marine glycosides. The excimer formation of pyrene, a hydrophobic fluorescent probe, was significantly decreased by triterpene glycosides. The increase of tryptophanyl residue fluorescence demonstrated a change of the Na+-K+-ATPase conformation after treatment with cytotoxic glycosides.
Gorshkova
I A
IA
Pacific Institute of Bioorganic Chemistry, Far East Branch of U.S.S.R. Academy of Sciences, Vladivostok.
Kalinovsky
A I
AI
Ilyin
S G
SG
Gorshkov
B A
BA
Stonik
V A
VA
D000818:Animals; D001921:Brain / Q000201:enzymology* / Q000648:ultrastructure; D006027:Glycosides / Q000494:pharmacology*; D009682:Magnetic Resonance Spectroscopy; D008854:Microscopy, Electron; D011721:Pyrenes / Q000032:analysis; D051381:Rats; D012616:Sea Cucumbers; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors*; D013050:Spectrometry, Fluorescence; D013696:Temperature; D014315:Triterpenes / Q000494:pharmacology*; D014364:Tryptophan / Q000032:analysis; D014961:X-Ray Diffraction
D006027:Glycosides; D011721:Pyrenes; D014315:Triterpenes; D014364:Tryptophan; C030984:pyrene; D000254:Sodium-Potassium-Exchanging ATPase