CHROMOPHORE-CHROMOPHORE INTERACTIONS IN UNFOLDED LABELED PROTEINS/NATIVE COND

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 通常认为，未折叠的蛋白质是无规卷曲，没有任何残余结构，目前正在严格审查。最近的一些NMR研究表明，未折叠状态具有大量的编码天然拓扑结构的残留结构。同时，许多小角X射线散射（SAXS）和光散射测量表明，未折叠状态的平均尺寸对应于无规卷曲的预期尺寸。了解未折叠状态的结构对于许多蛋白质折叠研究至关重要。未折叠状态和部分未折叠的中间体也与许多蛋白质的聚集有关。只有相对较少的SAXS研究的未折叠状态下的原生条件下，我们提出的实验两个模型系统是专门设计来解决这个问题。另一个矛盾的问题，已经出现了从调查的展开状态是在SAXS和FRET测量之间观察到的结果的差异，对各种不同的蛋白质。为了进一步研究这种明显的差异，这是至关重要的解释了大量的合奏和单分子FRET研究，这将是非常有益的，如果这两种技术都适用于一个非折叠多肽与和没有FRET对。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The commonly held view that unfolded proteins are random coils without any residual structure is being rigorously scrutinized currently. Some recent NMR studies have indicated that the unfolded state has a significant amount of residual structure that encodes the native topology. At the same time a number of small angle x-ray scattering (SAXS) and light scattering measurements have indicated that the average dimensions of the unfolded state correspond to that expected for random coils. Understanding the structure of the unfolded state is critical to many protein-folding studies. The unfolded state and partially unfolded intermediates have also been implicated in the aggregation of many proteins. There have been only relatively few SAXS studies on the unfolded state under native like conditions and our proposed experiments on two model systems are specifically designed to address this issue. Another conflicting issue that has emerged from investigations of the unfolded state is the discrepancy in results observed between SAXS and FRET measurements on a variety of different proteins. To further investigate this apparent discrepancy, which is critical to the interpretation of a multitude of ensemble and single molecule FRET studies, it would be extremely beneficial if both techniques were applied to a non-folding polypeptide with and without a FRET pair.