该课题组引入了一种干涉式MINFLUX显微镜，可以以每毫秒1.7纳米的时空精度记录蛋白质的运动。相比之前需要在蛋白质上附着不成比例的大磁珠，MINFLUX仅需要检测约20个大小约为1纳米的荧光团的光子。因此，他们能够研究在生理腺苷-5'-三磷酸(ATP)浓度下，马达蛋白kinesin-1在微管上的步进。
研究人员发现在步进过程中无负载马达蛋白的茎部和头部会发生旋转，并表明ATP是由与微管结合的单个头部吸收的，当两个头部结合时发生ATP水解。他们的结果表明，MINFLUX以最小的干扰量化蛋白质的(亚)毫秒构象变化。
附：英文原文
Title: MINFLUX dissects the unimpeded walking of kinesin-1
Author: Jan O. Wolff, Lukas Scheiderer, Tobias Engelhardt, Johann Engelhardt, Jessica Matthias, Stefan W. Hell
Issue&Volume: 2023-03-10
Abstract: We introduce an interferometric MINFLUX microscope that records protein movements with up to 1.7 nanometer per millisecond spatiotemporal precision. Such precision has previously required attaching disproportionately large beads to the protein, but MINFLUX requires the detection of only about 20 photons from an approximately 1-nanometer-sized fluorophore. Therefore, we were able to study the stepping of the motor protein kinesin-1 on microtubules at up to physiological adenosine-5′-triphosphate (ATP) concentrations. We uncovered rotations of the stalk and the heads of load-free kinesin during stepping and showed that ATP is taken up with a single head bound to the microtubule and that ATP hydrolysis occurs when both heads are bound. Our results show that MINFLUX quantifies (sub)millisecond conformational changes of proteins with minimal disturbance.
DOI: ade2650
Source: https://www.science.org/doi/10.1126/science.ade2650