SAXS STUDIES OF PROTEIN FOLDING INTERMEDIATES

我们建议在两个水平上研究蛋白质折叠中间体 (a) 在适当的平衡条件下我们可以稳定 蛋白质的部分折叠状态和（b）通过直接动力学 使用停流时间分辨 SAXS 进行测量。 SAXS 数据产量 构象状态的总体尺寸和形状指示 蛋白质。 细胞色素的高质量、大角度散射剖面 c 是在不同变性剂浓度下测量的。 我们会 结合使用奇异值分解分析和 变性剂结合模型以确定是否达到平衡 存在中间状态。 此分析遵循用于 区分溶菌酶的折叠中间体（Chen，J. Mol. Biol. 261、658-671）。 A 态，部分折叠的中间态 在低pH值下添加盐获得的，脱辅基肌红蛋白具有 并用 SAXS 进行了表征。 脱辅基肌红蛋白 A 状态稳定 TFA、TCA 和 KCl 表现出不同程度的压实， 表明不存在唯一的 A 状态。

We propose to study protein folding intermediates at two levels (a) under suitable equilibrium conditions where we can stabilize partially folded states of proteins and (b) by direct kinetic measurements using stopped-flow time-resolved SAXS. SAXS data yield overall size and shape indication of the conformational state of a protein. High-quality, high-angle scattering profiles for cytochrome c have been measured at varying denaturant concentrations. We will use the combination of singular value decomposition analysis and a denaturant binding model to determine whether an equilibrium intermediate state exists. This analysis follows the method used to distinguish a folding intermediate for lysozyme (Chen, J. Mol. Biol. 261, 658-671). The A-states, partially folded intermediate states obtained at low pH with the addition of salt, of apomyoglobin have been characterized with SAXS. The apomyoglobin A-states stabilized with TFA, TCA, and KCl demonstrated different degrees of compaction, suggesting that there is not a unique A-state.