Abstract
Structure determination of biomacromolecules under in-cell conditions is a relevant yet challenging task. Electron paramagnetic resonance (EPR) distance measurements in combination with site-directed spin labeling (SDSL) are a valuable tool in this endeavor but the usually used nitroxide spin labels are not well-suited for in-cell measurements. In contrast, triarylmethyl (trityl) radicals are highly persistent, exhibit a long relaxation time and a narrow spectral width. Here, the synthesis of a versatile collection of trityl spin labels and their application in in vitro and in-cell trityl–iron distance measurements on a cytochrome P450 protein are described. The trityl labels show similar labeling efficiencies and better signal-to-noise ratios (SNR) as compared to the popular methanethiosulfonate spin label (MTSSL) and enabled a successful in-cell measurement.
Original language | English |
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Pages (from-to) | 177-181 |
Number of pages | 5 |
Journal | Angewandte Chemie International Edition in English |
Volume | 56 |
Issue number | 1 |
DOIs | |
State | Published - 2 Jan 2017 |
Externally published | Yes |
Keywords
- EPR spectroscopy
- distance measurements
- in-cell spectroscopy
- protein structures
- spin labeling