Robustness and Sensitivity of Gd(III)-Gd(III) Double Electron-Electron Resonance (DEER) Measurements: Comparative Study of High-Frequency EPR Spectrometer Designs and Spin Label Variants.

ABSTRACT: In this paper, we explore the robustness and sensitivity of Gd(III)-Gd(III) double electron-electron resonance (DEER) distance measurements in proteins for different spectrometer designs and three spin labels. To do this a protein was labeled at the same two positions with Gd(III) spin labels and measurements were performed on two home-built high-frequency (W-band, ~ 95 GHz) EPR spectrometers with different design approaches, and a commercial 150 W Q-band (34 GHz) spectrometer. The first W-band measurement approach uses a conventional, narrow band single mode cavity, while the second uses a broadband non-resonant induction mode sample holder. Both systems incorporate advanced arbitrary waveform generators (AWGs) that give flexibility over excitation bandwidth. We use three DOTA-like Gd(III

SUBMITTER: Mocanu EM 

PROVIDER: S-EPMC12033185 | biostudies-literature | 2025

REPOSITORIES: biostudies-literature