A simple model for the cooperative stabilisation of actin filaments by phalloidin and jasplakinolide.
The stabilisation of magnesium actin filaments by phalloidin and jasplakinolide was studied using the method of differential scanning calorimetry. The results showed that actin could adapt three conformations in the presence of drugs. One conformation was adapted in direct interaction with the drug, while another conformation was identical to that observed in the absence of drugs. A third conformation was induced through allosteric inter-protomer interactions. The effect of both drugs propagated cooperatively along the actin filaments. The number of the cooperative units determined by using a quantitative model was larger for jasplakinolide (15 actin protomers) than for phalloidin (7 protomers).
Visegrády
Balázs
B
Department of Biophysics, Faculty of Medicine, University of Pécs, Szigeti str. 12, Pécs H-7624, Hungary.
Lorinczy
Dénes
D
Hild
Gábor
G
Somogyi
Béla
B
Nyitrai
Miklós
M
D008841:Actin Cytoskeleton / Q000737:chemistry* / Q000187:drug effects* / Q000378:metabolism; D000818:Animals; D002152:Calorimetry, Differential Scanning; D047630:Depsipeptides / Q000494:pharmacology*; D008274:Magnesium / Q000378:metabolism; D008956:Models, Chemical; D008968:Molecular Conformation; D010590:Phalloidine / Q000494:pharmacology*; D011817:Rabbits; D013696:Temperature
D047630:Depsipeptides; C057531:jasplakinolide; D010590:Phalloidine; D008274:Magnesium