STRUCTURAL STUDIES OF AUXILIARY SUBUNITS OF VOLTAGE DEP POTASSIUM CHANNELS

该子项目是利用NIH/NCRR资助的中心赠款提供的资源的许多研究子项目之一。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。所列机构为中心，不一定是研究者所在机构。钾通道在许多生理过程中是重要的，例如神经元的兴奋性、激素的分泌和肌肉细胞的收缩。在细胞中，所有钾离子通道都与其他胞质或跨膜蛋白组装，并且通道功能由这些蛋白调节。我们在原子水平上研究了通道调制的分子机制。Kvbeta是一种氧化还原酶，附着在钾通道上。它在氧化和还原形式之间转换，并且转换调节通道功能。我们知道氧化蛋白的结构，但不知道还原蛋白的结构。为了得到还原的Kv β的结构，我们已经获得了还原形式的Kv β亚基的晶体，并且晶体在家庭来源处的折射率约为2.8埃。Chess的高强度光束将使我们能够收集更高分辨率的数据集，从而使蛋白质的构象变化清晰可见。我们将筛选冷冻晶体，并收集数据的那些表现优于2.5A。

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. Potassium channels are important in many physiological processes such as excitability of a neuron, secretion of hormones, and contraction of a muscle cell. In a cell, all potassium channels are assembled with other cytosolic or transmembrane proteins, and channel functions modulated by these proteins. We study the molecular mechanism of channel modulation at the atomic level. Kvbeta is an oxidoreductase that attaches to a potassium channel. It converts between the oxidized and reduced forms and the conversion modulates channel function. We know the structure of the oxidized protein, but not the reduced one. In an effort to get the structure of the reduced Kvbeta, we have obtained crystals of Kvbeta subunit in the reduced form, and the crystals diffract to about 2.8 angstrom at a home source. The high intensity beam at Chess will enable us to collect higher resolution data sets, so that the conformational changes of the protein will be visualized clearly. We will screen frozen crystals, and collect data on ones that diffract to better than 2.5A.