Max Planck Fellow Chemical Biology, Center of Advanced European Studies and Research (caesar), Ludwig-Erhard-Allee 2, 53175, Bonn, Germany.
LIMES Chemical Biology Unit, Rheinische Friedrich-Wilhelms-Universität Bonn, Gerhard-Domagk-Strasse 1, 53121, Bonn, Germany.
Angew Chem Int Ed Engl. 2017 Jul 10;56(29):8417-8421. doi: 10.1002/anie.201703154. Epub 2017 Jun 19.
The synthesis of a spin label based on PD168393, a covalent inhibitor of a major anticancer drug target, the epidermal growth factor receptor (EGFR), is reported. The label facilitates the analysis of the EGFR structure in solution by pulsed electron paramagnetic resonance (EPR) spectroscopy. For various EGFR constructs, including near-full-length EGFR, we determined defined distance distributions between the two spin labels bound to the ATP binding sites of the EGFR dimer. The distances are in excellent agreement with an asymmetric dimer of the EGFR. Based on crystal structures, this dimer had previously been proposed to reflect the active conformation of the receptor but structural data demonstrating its existence in solution have been lacking. More generally, our study provides proof-of-concept that inhibitor-based spin labeling enables the convenient introduction of site-specific spin labels into kinases for which covalent or tight-binding small-molecule modulators are available.
报道了一种基于 PD168393 的自旋标记物的合成，PD168393 是一种抗癌药物靶点表皮生长因子受体（EGFR）的共价抑制剂。该标记物通过脉冲电子顺磁共振（EPR）光谱法促进了 EGFR 在溶液中的结构分析。对于包括近全长 EGFR 在内的各种 EGFR 构建体，我们确定了结合到 EGFR 二聚体 ATP 结合位点的两个自旋标记物之间的明确距离分布。这些距离与 EGFR 的不对称二聚体非常吻合。基于晶体结构，之前已经提出该二聚体反映了受体的活性构象，但缺乏证明其在溶液中存在的结构数据。更普遍地说，我们的研究提供了概念验证，即基于抑制剂的自旋标记物能够方便地将位点特异性自旋标记物引入到可用共价或紧密结合的小分子调节剂的激酶中。
