Following Protein Dynamics in Real Time during Crystallization
Following Protein Dynamics in Real Time during Crystallization
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DOI：
10.1021/acs.cgd.9b00858
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发表时间：
2019-10
影响因子：
3.8
通讯作者：
C. Beck;M. Grimaldo;F. Roosen‐Runge;R. Maier;O. Matsarskaia;Michal K. Braun;Benedikt Sohmen;O. Czakkel;R. Schweins;Fajun Zhang;T. Seydel;F. Schreiber
中科院分区：
文献类型：
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作者：
C. Beck;M. Grimaldo;F. Roosen‐Runge;R. Maier;O. Matsarskaia;Michal K. Braun;Benedikt Sohmen;O. Czakkel;R. Schweins;Fajun Zhang;T. Seydel;F. Schreiber
从蛋白质水溶液中结晶蛋白质的过程仍然没有得到充分的理解。在宏观晶体形成过程中，通常发生在几小时到几天的时间尺度上，蛋白质动力学在分子水平上演变。在这里，我们提出了一个概念的证明和框架，观察这种不断发展的扩散动力学的皮科到纳秒的时间尺度，与集群或前体的形成，最终导致新兴的晶体。我们研究了蛋白质β-乳球蛋白在D2 O中的ZnCl 2存在下的模型系统，其通过静电桥诱导结晶。首先，在结晶过程中发生的结构变化，其次是小角中子散射。此外，我们采用中子背散射和自旋回波光谱测量的整体平均的自我和集体扩散的纳秒时间尺度上的蛋白质溶液的动力学时间分辨率的顺序为15分钟。实验提供的信息固定化蛋白质的数量分数的增加，以及在一个日益枯竭的阶段未结合的蛋白质的扩散运动。同时，获得了关于蛋白质内部动力学的信息。
The process of protein crystallization from aqueous protein solutions is still insufficiently understood. During macroscopic crystal formation, occurring often on time scales from a few hours to several days, protein dynamics evolves on the molecular level. Here, we present a proof of concept and a framework to observe this evolving diffusive dynamics on the pico- to nanosecond time scale, associated with cluster or precursor formation that ultimately results in emerging crystals. We investigated the model system of the protein β-lactoglobulin in D2O in the presence of ZnCl2, which induces crystallization by electrostatic bridges. First, the structural changes occurring during crystallization were followed by small-angle neutron scattering. Furthermore, we employed neutron backscattering and spin-echo spectroscopy to measure the ensemble-averaged self- and collective diffusion on nanosecond time scales of protein solutions with a kinetic time resolution on the order of 15 min. The experiments provide information on the increasing number fraction of immobilized proteins as well as on the diffusive motion of unbound proteins in an increasingly depleted phase. Simultaneously, information on the internal dynamics of the proteins is obtained.