A Gadolinium Spin Label with Both a Narrow Central Transition and Short Tether for Use in Double Electron Electron Resonance Distance Measurements

Shah, Anokhi; Roux, Amandine; Starck, Matthieu; Mosely, Jackie A.; Stevens, Michael; Norman, David G.; Hunter, Robert I.; El Mkami, Hassane; Smith, Graham M.; Parker, David; Lovett, Janet E.

Abstract

The design, synthesis, and application of a nine-coordinate gadolinium(III)-containing spin label, [Gd.sTPATCN]-SL, for use in nanometer-distance measurement experiments by EPR spectroscopy is presented. The spin label links to cysteines via a short thioether tether and has a narrow central transition indicative of small zero-field splitting (ZFS). A protein homodimer, TRIM25cc, was selectively labeled with [Gd.sTPATCN]-SL (70%) and a nitroxide (30%) under mild conditions and measured using the double electron electron resonance (DEER) technique with both commercial Q-band and home-built W-band spectrometers. The label shows great promise for increasing the sensitivity of DEER measurements through both its favorable relaxation parameters and the large DEER modulation depth at both Q- and W-band for the inter-Gd(III) DEER measurement which, at 9%, is the largest recorded under these conditions.

Citation

Shah, A., Roux, A., Starck, M., Mosely, J. A., Stevens, M., Norman, D. G., Hunter, R. I., El Mkami, H., Smith, G. M., Parker, D., & Lovett, J. E. (2019). A Gadolinium Spin Label with Both a Narrow Central Transition and Short Tether for Use in Double Electron Electron Resonance Distance Measurements. Inorganic Chemistry, 58(5), 3015-3025. https://doi.org/10.1021/acs.inorgchem.8b02892

• Journal Article Type: Article
• Online Publication Date: Feb 18, 2019
• Publication Date: Mar 4, 2019
• Deposit Date: Feb 19, 2019
• Publicly Available Date: Feb 18, 2020
• Journal: Inorganic Chemistry
• Print ISSN: 0020-1669
• Electronic ISSN: 1520-510X
• Publisher: American Chemical Society
• Peer Reviewed: Peer Reviewed
• Volume: 58
• Issue: 5
• Pages: 3015-3025
• DOI: https://doi.org/10.1021/acs.inorgchem.8b02892
• Public URL: https://durham-repository.worktribe.com/output/1337311