Cousin Samuel F, Kadeřávek Pavel, Bolik-Coulon Nicolas, Gu Yina, Charlier Cyril, Carlier Ludovic, Bruschweiler-Li Lei, Marquardsen Thorsten, Tyburn Jean-Max, Brüschweiler Rafael, Ferrage Fabien
Laboratoire des biomolécules, LBM, Département de chimie , École normale supérieure, PSL University, Sorbonne Université, CNRS , 75005 Paris , France.
Department of Chemistry and Biochemistry , The Ohio State University , Columbus , Ohio 43210 , United States.
J Am Chem Soc. 2018 Oct 17;140(41):13456-13465. doi: 10.1021/jacs.8b09107. Epub 2018 Sep 24.
Motions of proteins are essential for the performance of their functions. Aliphatic protein side chains and their motions play critical roles in protein interactions: for recognition and binding of partner molecules at the surface or serving as an entropy reservoir within the hydrophobic core. Here, we present a new NMR method based on high-resolution relaxometry and high-field relaxation to determine quantitatively both motional amplitudes and time scales of methyl-bearing side chains in the picosecond-to-nanosecond range. We detect a wide variety of motions in isoleucine side chains in the protein ubiquitin. We unambiguously identify slow motions in the low nanosecond range, which, in conjunction with molecular dynamics computer simulations, could be assigned to transitions between rotamers. Our approach provides unmatched detailed insight into the motions of aliphatic side chains in proteins and provides a better understanding of the nature and functional role of protein side-chain motions.
蛋白质的运动对于其功能的发挥至关重要。脂肪族蛋白质侧链及其运动在蛋白质相互作用中起着关键作用：用于在表面识别和结合伴侣分子，或作为疏水核心内的熵库。在此，我们提出一种基于高分辨率弛豫测量和高场弛豫的新核磁共振方法，用于定量测定皮秒至纳秒范围内含甲基侧链的运动幅度和时间尺度。我们在蛋白质泛素的异亮氨酸侧链中检测到了各种各样的运动。我们明确识别出低纳秒范围内的慢运动，结合分子动力学计算机模拟，这些运动可归因于旋转异构体之间的转变。我们的方法为蛋白质中脂肪族侧链的运动提供了无与伦比的详细见解，并有助于更好地理解蛋白质侧链运动的本质和功能作用。
