Institute for Biophysical Chemistry, Hannover Medical School, Germany.
FEBS Lett. 2011 Mar 9;585(5):767-71. doi: 10.1016/j.febslet.2011.01.042. Epub 2011 Feb 3.
Phalloidin and fluorescently labeled phalloidin analogs are established reagents to stabilize and mark actin filaments for the investigation of acto-myosin interactions. In the present study, we employed transient and steady-state kinetic measurements as well as in vitro motility assays to show that phalloidin perturbs the productive interaction of human non-muscle myosin-2A and -2C1 with filamentous actin. Phalloidin binding to F-actin results in faster dissociation of the complex formed with non-muscle myosin-2A and -2C1, reduced actin-activated ATP turnover, and slower velocity of actin filaments in the in vitro motility assay. In contrast, phalloidin binding to F-actin does not affect the interaction with human non-muscle myosin isoform 2B and Dictyostelium myosin-2 and myosin-5b.
鬼笔环肽和荧光标记的鬼笔环肽类似物是稳定和标记肌动蛋白丝的常用试剂，用于研究肌动球蛋白相互作用。在本研究中，我们采用瞬态和稳态动力学测量以及体外运动分析，表明鬼笔环肽会破坏人非肌肉肌球蛋白-2A 和 -2C1 与丝状肌动蛋白的有效相互作用。鬼笔环肽与 F-肌动蛋白的结合导致与非肌肉肌球蛋白-2A 和 -2C1 形成的复合物更快解离，降低了肌动蛋白激活的 ATP 周转率，并减缓了体外运动分析中肌动蛋白丝的速度。相比之下，鬼笔环肽与 F-肌动蛋白的结合并不影响与人非肌肉肌球蛋白同工型 2B 和盘基网柄菌肌球蛋白-2 和肌球蛋白-5b 的相互作用。
