NEUROTRANSMITTER RECEPTOR PURIFICATION AND STRUCTURE

神经递质受体;肾上腺素能（β 1、β 2、α 1和α 2）， 胆碱能（毒蕈碱和烟碱）、多巴胺能和多巴胺能 受体正在被分离和纯化，以了解 受体功能和神经元通讯的分子基础。 具体 目前正在进行项目，以提供每一个 上述受体蛋白。 获得的结构数据包括 一级序列数据、蛋白水解消化图谱、拓扑信息和 结构-功能数据，例如神经递质结合位点定位， 糖定位、膜结构域和效应偶联蛋白 识别域。 我们的数据表明， 在非神经递质相关的神经递质之间存在相似性， 受体（毒蕈碱，胆碱能和α肾上腺素能），这些 神经递质受体通过蛋白质介导细胞调节 神经递质结合到结合物引发的构象变化 在胞外蛋白质结构域中的位点。 受体偶联是由 受体的细胞质“尾”似乎是效应物， 蛋白（GTP调节蛋白）识别部分的受体。 已经建立了蛋白质制备程序，其包括各种 HPLC步骤，配体亲和色谱，单克隆抗体亲和 层析，制备型SDS-凝胶电泳，凝集素亲和 色谱法、离子交换色谱法和柱等电 专注 这些纯化方案的建立现在是 允许同时对所有肾上腺素能受体进行详细的结构比较 和胆碱能受体蛋白。 分离的功能性受体蛋白 通过亲和层析和HPLC， 磷脂囊泡与纯化的GTP调节蛋白（Gi 和Go）来研究参与细胞调控的分子事件， 受体蛋白的作用。

Neurotransmitter receptors; adrenergic (beta1, beta2, alpha1 and alpha2), cholinergic (muscarinic and nicotinic), dopaminergic, and serotonergic receptors are being isolated and purified in order to understand the molecular basis of receptor function and neuronal communication. Specific projects are underway to provide precise structural information on each of the above receptor proteins. Structural data being obtained include primary sequence data, proteolytic digest maps, topology information and structure-function data, e.g. neurotransmitter binding site localization, sugar localization, membrane domain and effector coupling protein recognition domains. Our data have demonstrated that structural similarities exist amongst non-pharmacologically related neurotransmitter receptors (muscarinic, cholinergic and alpha adrenergic) and that these neurotransmitter receptors mediate cellular modulation via protein conformational changes initiated by neurotransmitter binding to the binding site in the extracellular protein domain. Receptor coupling is mediated by the cytoplasmic "tail" of the receptors which appears to be the effector protein (GTP-regulatory protein) recognition portion of the receptor. Protein preparative procedures have been established which include various HPLC steps, ligand affinity chromatography, monoclonal antibody affinity chromatography, preparative SDS-gel electrophoresis, lectin affinity chromatography, ion exchange chromatography and column isoelectric focusing. The establishment of these purification protocols are now permitting simultaneous detailed structural comparisons of all adrenergic and cholinergic receptor proteins. Functional receptor proteins isolated by affinity chromatography and HPLC are being reconstituted into phospholipid vesicles together with purified GTP-regulatory proteins (Gi and Go) to study molecular events involved in the control of cellular events by receptor proteins.