ULTRAFAST MEASUREMENTS OF PROTEIN FOLDING USING SAXS

提出了快速连续流技术的应用。 进行早期小角X射线散射(SAXS)测量 蛋白质折叠的阶段在1-50ms的时间范围内。传统的 停流SAXS技术的时间分辨率为&gt；50ms和 停滞时间为10毫秒。使用喷气混合器，死区时间将是 减小到1毫秒，时间分辨率应达到1毫秒。 SAXS与快速连续混合技术的结合 技术，我们将测量一种未折叠的蛋白质的压缩速度 当它突然被置于自然条件下时。SAXS是唯一的 已知的时间分辨技术，可给出整体尺寸和形状 蛋白质构象状态的指示。SAXS数据可能是 用于确定回转半径并获得形状 可以从Kratky情节和这对情侣中推断的信息 分布函数。停流的最早数据点 技术通常表现出相对紧凑结构 展开的状态。随着时间分辨率的显著提高 并减少停滞时间，我们将能够研究压实率 在重新折叠的早期阶段彻底完成。

We propose the application of the rapid continuous flow technique to make small angle x-ray scattering (SAXS) measurements of the early stages of protein folding in the 1-50 ms time range. The conventional stopped-flow SAXS technique results in a time resolution of >50 ms and a dead time of 10 ms. Using a jet-mixer, the dead time will be reduced to 1 ms and a time resolution of 1 ms should be achieved. Using the combination of SAXS and the rapid continuous mixing technique, we will measure an unfolded protein's rate of compaction when it is suddenly placed under native conditions. SAXS is the only known time-resolved technique which gives overall size and shape indication of the conformational state of a protein. SAXS data may be used to determine the radius of gyration and to obtain shape information which may be inferred from the Kratky plot and the pair distribution function. The earliest data points for the stopped-flow technique usually show a relatively compact structure as compared to the unfolded state. With the dramatically improved time resolution and reduced dead time, we will be able to study the rate of compaction thoroughly at the early stages of refolding.