Braun Michal K, Grimaldo Marco, Roosen-Runge Felix, Hoffmann Ingo, Czakkel Orsolya, Sztucki Michael, Zhang Fajun, Schreiber Frank, Seydel Tilo
Institut für Angewandte Physik, Universität Tübingen , Auf der Morgenstelle 10, 72076 Tübingen, Germany.
Institut Laue-Langevin , 71 Avenue des Martyrs, 38000 Grenoble, France.
J Phys Chem Lett. 2017 Jun 15;8(12):2590-2596. doi: 10.1021/acs.jpclett.7b00658. Epub 2017 May 30.
We investigate the concentration-controlled formation of clusters in β-lactoglobulin (BLG) protein solutions combining structural and dynamical scattering techniques. The static structure factor from small-angle X-ray scattering as well as de-Gennes narrowing in the nanosecond diffusion function D(q) from neutron spin echo spectroscopy support a picture of cluster formation. Using neutron backscattering spectroscopy, a monotonous increase of the average hydrodynamic cluster radius is monitored over a broad protein concentration range, corresponding to oligomeric structures of BLG ranging from the native dimers up to roughly four dimers. The results suggest that BLG forms compact clusters that are static on the observation time scale of several nanoseconds. The presented analysis provides a general framework to access the structure and dynamics of macromolecular assemblies in solution.
我们结合结构和动态散射技术，研究了β-乳球蛋白（BLG）蛋白质溶液中浓度控制的聚集体形成。小角X射线散射的静态结构因子以及中子自旋回波光谱中纳秒扩散函数D(q)的德热纳窄化，都支持聚集体形成的图像。利用中子背散射光谱，在较宽的蛋白质浓度范围内监测到平均流体动力学聚集体半径单调增加，这对应于BLG从天然二聚体到大约四个二聚体的寡聚结构。结果表明，BLG形成了在几纳秒的观察时间尺度上是静态的紧密聚集体。所提出的分析提供了一个通用框架，用于研究溶液中大分子聚集体的结构和动力学。
