Takács-Kollár Veronika, Nyitrai Miklós, Hild Gábor
University of Pécs, Medical School, Department of Biophysics, Pécs, Szigeti Str. 12, H-7624, Hungary.
University of Pécs, Medical School, Department of Biophysics, Pécs, Szigeti Str. 12, H-7624, Hungary; Szentágothai Research Center, Pécs, Ifjúság Str. 34, H-7624, Hungary; MTA-PTE Nuclear-Mitochondrial Interactions Research Group, Pécs, Szigeti Str. 12, H-7624, Hungary.
Biochim Biophys Acta. 2016 Jul;1864(7):840-6. doi: 10.1016/j.bbapap.2016.04.002. Epub 2016 Apr 12.
The effect of twinfilin-1 on the structure and dynamics of monomeric actin was investigated with fluorescence spectroscopy and differential scanning calorimetry experiments. Fluorescence anisotropy measurements proved that G-actin and twinfilin-1 could form a complex. Due to the formation of the complexes the dissociation of the nucleotide slowed down from the nucleotide-binding pocket of actin. Fluorescence quenching experiments showed that the accessibility of the actin bound ε-ATP decreased in the presence of twinfilin-1. Temperature dependent fluorescence resonance energy transfer and differential scanning calorimetry experiments revealed that the protein matrix of actin becomes more rigid and more heat resistant in the presence of twinfilin-1. The results suggest that the nucleotide binding cleft shifted into a more closed and stable conformational state of actin in the presence of twinfilin-1.
利用荧光光谱和差示扫描量热法实验研究了双肌动蛋白-1对单体肌动蛋白结构和动力学的影响。荧光各向异性测量证明G-肌动蛋白和双肌动蛋白-1可以形成复合物。由于复合物的形成，核苷酸从肌动蛋白的核苷酸结合口袋解离的速度减慢。荧光猝灭实验表明，在双肌动蛋白-1存在下，肌动蛋白结合的ε-ATP的可及性降低。温度依赖性荧光共振能量转移和差示扫描量热法实验表明，在双肌动蛋白-1存在下，肌动蛋白的蛋白质基质变得更刚性且更耐热。结果表明，在双肌动蛋白-1存在下，核苷酸结合裂隙转变为肌动蛋白更封闭和稳定的构象状态。
