XRAY SCATTERING MEASUREMENTS OF RAPID CHAIN COLLAPSE DURING PROTEIN FOLDING

我们建议进行时间分辨的SAXS测量 全是β-折叠α-淀粉酶蛋白，肌腱。它是从 光学动力学测量这种蛋白质直接折叠到 在大约5毫秒内处于本机状态，而无需通过部分 折叠中间体。我们计划测量星体半径的变化 蛋白质在以下条件下展开的旋转： 可将折叠常数减慢至50毫秒之间 通过增加最终变性剂浓度和/或 使用折叠率降低的突变蛋白。这将是 使我们能够测试一种非特定聚合物坍塌的假说 必须发生在向本机构象的过渡态之前 已进入。

We propose to perform time-resolved SAXS measurements of the small all beta sheet alpha amylase protein, tendamistat. It is known from optical kinetic measurements that this protein folds directly to the native state in around 5 millisecs without going through a partially folded intermediate. We plan to measure changes of the radius of gyration of the protein unfolding under conditions where the rate constant for folding may be slowed down to a rate between 50 millisecs to 1 sec by increasing the final denaturant concentration and/or by using a mutant protein with a decreased folding rate. This will enable us to test the hypothesis that a non-specific polymer collapse must occur before the transition state to the native conformation is entered.