GPCR Engineering Yields High-Resolution Structural Insights into β 2 -Adrenergic Receptor Function

作者：Daniel M. Rosenbaum, Vadim Cherezov, Michael A. Hanson, Søren G. F. Rasmussen, Foon Sun Thian, Tong Sun Kobilka, Hee‐Jung Choi, Xiao-Jie Yao, William I. Weis, Raymond C. Stevens, Brian K. Kobilka · 发表于：Science · 年份：2007 · DOI：10.1126/science.1150609 · 被引用次数：1346 · 研究领域：Receptor Mechanisms and Signaling、Neuropeptides and Animal Physiology、Pharmacological Effects and Assays

The beta2-adrenergic receptor (beta2AR) is a well-studied prototype for heterotrimeric guanine nucleotide-binding protein (G protein)-coupled receptors (GPCRs) that respond to diffusible hormones and neurotransmitters. To overcome the structural flexibility of the beta2AR and to facilitate its crystallization, we engineered a beta2AR fusion protein in which T4 lysozyme (T4L) replaces most of the third intracellular loop of the GPCR ("beta2AR-T4L") and showed that this protein retains near-native pharmacologic properties. Analysis of adrenergic receptor ligand-binding mutants within the context of the reported high-resolution structure of beta2AR-T4L provides insights into inverse-agonist binding and the structural changes required to accommodate catecholamine agonists. Amino acids known to regulate receptor function are linked through packing interactions and a network of hydrogen bonds, suggesting a conformational pathway from the ligand-binding pocket to regions that interact with G proteins.