Projects per year
Electron paramagnetic resonance (EPR) distance measurements are making increasingly important contributions to the studies of biomolecules by providing highly accurate geometric constraints. Combining double-histidine motifs with CuII spin labels can further increase the precision of distance measurements. It is also useful for proteins containing essential cysteines that can interfere with thiol-specific labelling. However, the non-covalent CuII coordination approach is vulnerable to low binding-affinity. Herein, dissociation constants (KD) are investigated directly from the modulation depths of relaxation-induced dipolar modulation enhancement (RIDME) EPR experiments. This reveals low- to sub-μm CuII KDs under EPR distance measurement conditions at cryogenic temperatures. We show the feasibility of exploiting the double-histidine motif for EPR applications even at sub-μm protein concentrations in orthogonally labelled CuII–nitroxide systems using a commercial Q-band EPR instrument.
- Dissociation constant
- Double-histidine motif
- EPR spectroscopy
- Non-covalent interactions
FingerprintDive into the research topics of 'Sub-micromolar pulse dipolar EPR spectroscopy reveals increasing CuII-labelling of double-histidine motifs with lower temperature'. Together they form a unique fingerprint.
- 3 Finished
1/03/17 → 29/02/20
State of the art pulse EPR instrumentati: State of the art pulse EPR instrumentation for long range distance measurements in biomacromolecules
1/09/12 → 31/08/17
Data underpinning: Sub-micromolar pulse dipolar EPR spectroscopy reveals increasing Cu(II)-labelling of double-histidine motifs with lower temperature