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Studying the Conformation of a Receptor Tyrosine Kinase in Solution by Inhibitor‐Based Spin Labeling
Author(s) -
Yin Dongsheng M.,
Hannam Jeffrey S.,
Schmitz Anton,
Schiemann Olav,
Hagelueken Gregor,
Famulok Michael
Publication year - 2017
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201703154
Subject(s) - dimer , spin label , covalent bond , site directed spin labeling , electron paramagnetic resonance , chemistry , epidermal growth factor receptor , tyrosine kinase , egfr inhibitors , receptor tyrosine kinase , crystallography , nuclear magnetic resonance spectroscopy , small molecule , molecule , kinase , stereochemistry , receptor , nuclear magnetic resonance , biochemistry , physics , organic chemistry
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.