High-sensitivity Gd³⁺-Gd³⁺ EPR distance measurements that eliminate artefacts seen at short distances.

ABSTRACT: Gadolinium complexes are attracting increasing attention as spin labels for EPR dipolar distance measurements in biomolecules and particularly for in-cell measurements. It has been shown that flip-flop transitions within the central transition of the high-spin Gd3+ ion can introduce artefacts in dipolar distance measurements, particularly when measuring distances less than 3 nm. Previous work has shown some reduction of these artefacts through increasing the frequency separation between the two frequencies required for the double electron-electron resonance (DEER) experiment. Here we use a high-power (1 kW), wideband, non-resonant system operating at 94 GHz to evaluate DEER measurement protocols using two stiff Gd(III) rulers, consisting of two bis-Gd3+-PyMTA complexes, with separations of

SUBMITTER: El Mkami H 

PROVIDER: S-EPMC10500690 | biostudies-literature | 2020

REPOSITORIES: biostudies-literature