Steinmetz M O, Stoffler D, Müller S A, Jahn W, Wolpensinger B, Goldie K N, Engel A, Faulstich H, Aebi U
M.E. Müller Institute for Microscopy, University of Basel, Switzerland.
J Mol Biol. 1998 Feb 13;276(1):1-6. doi: 10.1006/jmbi.1997.1529.
We have prepared an undecagold-tagged phalloidin derivative to determine this mushroom toxin's binding site and orientation within the F-actin filament by scanning transmission electron microscopy (STEM) and 3-D helical reconstruction. Remarkably, when stoichiometrically bound to F-actin, the undecagold moiety of the derivative could be directly visualized by STEM along the two half-staggered long-pitch helical strands of single filaments. Most importantly, the structural data obtained when combined with various biochemical constraints enabled us to critically evaluate two distinct atomic models of the F-actin filament (i.e. the Holmes-Lorenz versus the Schutt-Lindberg model). Taken together, our data are in excellent agreement with the Holmes-Lorenz model.
我们制备了一种带有十一金标记的鬼笔环肽衍生物，通过扫描透射电子显微镜（STEM）和三维螺旋重建来确定这种蘑菇毒素在F-肌动蛋白丝中的结合位点和取向。值得注意的是，当以化学计量比与F-肌动蛋白结合时，衍生物的十一金部分可以通过STEM沿着单丝的两条半交错长间距螺旋链直接可视化。最重要的是，结合各种生化约束条件获得的结构数据使我们能够严格评估F-肌动蛋白丝的两种不同原子模型（即霍姆斯-洛伦兹模型与舒特-林德伯格模型）。综合来看，我们的数据与霍姆斯-洛伦兹模型非常吻合。
