Study of Interaction between Agonists and Asn293 in Helix VI of Human β<sub>2</sub>-Adrenergic Receptor
作者:Helene M. Zuurmond、Jutta Hessling、Klaus Blüml、Martin Lohse、Adriaan P. Ijzerman
DOI:10.1124/mol.56.5.909
日期:1999.11.1
Previously, we demonstrated the involvement of Asn293 in helix VI of the human β2-adrenergic receptor in stereoselective agonist recognition and activation. In the present study, we have further explored the role of this residue by synthesizing derivatives of isoproterenol and clenbuterol, two β-adrenergic receptor agonists. We analyzed their efficacy and affinity on the wild-type and a mutant receptor (Asn293Leu). Each compound had similar efficacy (τ values) on both the wild-type and mutant receptor, although τ values varied considerably among the eight compounds studied. It appeared that one derivative of isoproterenol, but not of clenbuterol, showed a gain in affinity from the wild type to the mutant receptor. This derivative had a methyl substituent instead of the usual β-OH group in the aliphatic side chain of isoproterenol, compatible with the more lipophilic nature of the leucine side chain. Such a “gain of function” approach through a combination of synthetic chemistry with molecular biology, may be useful to enhance our insight into the precise atomic events that govern ligand-receptor interactions.
此前,我们证明了人β2-肾上腺素受体螺旋VI中的Asn293参与立体选择性激动剂识别和激活。在本研究中,我们通过合成两种β-肾上腺素受体激动剂异丙肾上腺素和克仑特罗的衍生物,进一步探讨了该残基的作用。我们分析了它们对野生型和突变型受体 (Asn293Leu) 的功效和亲和力。每种化合物对野生型和突变型受体都具有相似的功效(τ 值),尽管所研究的八种化合物之间的 τ 值差异很大。似乎异丙肾上腺素的一种衍生物(而不是克仑特罗)显示出野生型与突变型受体的亲和力增加。该衍生物在异丙肾上腺素的脂肪族侧链上具有甲基取代基,而不是常见的 β-OH 基团,与亮氨酸侧链的亲脂性相容。这种通过合成化学与分子生物学相结合的“功能获得”方法可能有助于增强我们对控制配体-受体相互作用的精确原子事件的了解。