THREE DIMENSIONAL MODELS FOR MEMBRANE RECEPTOR PROTEINS

整合膜受体蛋白通常在信号转导中起关键作用。 细菌和高等细菌的跨细胞膜转导 有机体。对三维结构的详细了解 这些受体蛋白无疑将对 对信号分子机制的一般理解 转导，但巨大的技术挑战阻碍了常规 大多数膜蛋白高分辨结构的测定 目前。因此，计算机建模研究被提出以 为细菌膜生成详细的三维模型 化学受体，来自大肠杆菌的Trg受体和一些 哺乳动物七种螺旋G蛋白偶联受体，包括肾上腺素能 和多巴胺神经递质受体，以及CCK-A肽受体。 肾上腺素能和多巴胺受体配基的几个具体问题 结合和选择性将使用分子建模来解决 技术和现有的实验数据。分子模拟研究 并将对CCK-A进行光亲和标记实验 Receptor与梅奥诊所的劳伦斯·米勒教授合作， 以充分描述激动剂和拮抗剂结合部位。最后一盘 的模型研究将与教授合作进行。 华盛顿州立大学的杰拉尔德·哈泽尔鲍尔将生成详细的 细菌Trg化学受体的三维模型。利用 来自巯基可及性、交联和自旋标记的数据 由Hazelbauer教授的研究小组进行的研究， 受体的跨膜和周质结构域将被 构建了构象变化模型，并建立了与 将探索信号转导。模型结构将是 使用新的实验数据不断地评估和提炼。 哈泽尔鲍尔的实验室。详细的模型构建与 与实验小组的密切合作应该会产生有用的新 关于两个基因的结构和信号转导机制的信息 不同类别的膜受体蛋白。为以下项目获取的信息 肾上腺素能、多巴胺和CCK-A受体也可能在 针对这些受体的药理制剂的设计。

Integral membrane receptor proteins often play a key role in signal transduction across cell membranes in both bacteria and higher organisms. Detailed knowledge of the three-dimensional structures of these receptor proteins would undoubtedly contribute greatly to a general understanding of the molecular mechanisms of signal transduction, but formidable technical challenges prohibit the routine determination of high resolution structures for most membrane proteins at present. Therefore, computer modeling studies are proposed to generate detailed three-dimensional models for a bacterial membrane chemoreceptor, the Trg receptor from Escherichia coli, and a number of mammalian seven helix G protein-coupled receptors, including adrenergic and dopamine neurotransmitter receptors, and CCK-A peptide receptor. Several specific issues of adrenergic and dopamine receptor ligand binding and selectivity will be addressed utilizing molecular modeling techniques and existing experimental data. Molecular modeling studies and photoaffinity labeling experiments will be performed for CCK-A receptor, in collaboration with Prof. Laurence Miller at Mayo Clinic, to fully characterize agonist and antagonist binding sites. A final set of modeling studies will be undertaken in collaboration with Prof. Gerald Hazelbauer at Washington State University to generate detailed three-dimensional models for the bacterial Trg chemoreceptor. Utilizing data from sulfhydryl accessibility, crosslinking, and spin labeling studies performed by Prof. Hazelbauer's group, structures for the transmembrane and periplasmic domains of the receptor will be constructed, and models for the conformational changes associated with signal transduction will be explored. The model structures will be continually evaluated and refined using new experimental data from Prof. Hazelbauer's laboratory. The combination of detailed model building and close collaboration with experimental groups should yield useful new information about structure and signal transduction mechanisms for two distinct classes of membrane receptor proteins. Information obtained for the adrenergic, dopamine, and CCK-A receptors may also be of use in design of pharmacological agents targeted to these receptors.