Dancker P, Löw I, Hasselbach W, Wieland T
Biochim Biophys Acta. 1975 Aug 19;400(2):407-14. doi: 10.1016/0005-2795(75)90196-8.
The cyclic peptide phalloidin, one of the toxic components of Amanita phalloides prevented the drop of viscosity of F-actin solutions after the addition of 0.6 M KI and inhibited the ATP splitting of F-actin during sonic vibration. The data concerning ATP splitting are consistent with the assumption (a) that only 1 out of every 3 actin units of the filaments needs to be combined with phalloidin in order to suppress the contribution of these 3 actins to the ATPase activity of the filament and (b) that all actin units of the filaments can combine with phalloidin with a very high affinity. -halloidin did not only stabilize the actin-actin bonds in the F-actin structure but it also increased the rate of polymerization of G-actin to F-actin. The ability of F-actin to activate myosin ATPase was not affected by phalloidin. The tropomyosin-troponin complex did not prevent the stabilizing effect of phalloidin on the F-actin structure.
环肽鬼笔环肽是毒蝇伞的有毒成分之一，它能阻止在加入0.6M KI后F-肌动蛋白溶液粘度的下降，并在超声振动期间抑制F-肌动蛋白的ATP分解。关于ATP分解的数据与以下假设一致：(a) 为了抑制这3个肌动蛋白对细丝ATP酶活性的贡献，细丝中每3个肌动蛋白单位中只需有1个与鬼笔环肽结合；(b) 细丝中的所有肌动蛋白单位都能以非常高的亲和力与鬼笔环肽结合。鬼笔环肽不仅稳定了F-肌动蛋白结构中的肌动蛋白-肌动蛋白键，还提高了G-肌动蛋白向F-肌动蛋白聚合的速率。F-肌动蛋白激活肌球蛋白ATP酶的能力不受鬼笔环肽的影响。原肌球蛋白-肌钙蛋白复合物不能阻止鬼笔环肽对F-肌动蛋白结构的稳定作用。
