Sensitive Cu2+鈥揅u2+ Distance Measurements in a Protein鈥揇NA Complex by Double-Quantum Coherence ESR

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• 作者：Sharon Ruthstein ; Ming Ji ; Preeti Mehta ; Linda Jen-Jacobson ; Sunil Saxena
• 刊名：The Journal of Physical Chemistry B
• 出版年：2013
• 出版时间：May 23, 2013
• 年：2013
• 卷：117
• 期：20
• 页码：6227-6230
• 全文大小：194K
• 年卷期：v.117,no.20(May 23, 2013)
• ISSN：1520-5207

文摘

Double quantum coherence (DQC) ESR spectroscopy is applied to measure the Cu²⁺鈥揅u²⁺ distance in the EcoRI-DNA complex. A simple method is proposed to reduce the contribution of nuclear hyperfine and quadrupole interactions to such data. The effects of such interactions between the electron spin of Cu²⁺ and neighboring nuclei on the DQC data make it difficult to measure the nanometer range interspin distance. The DQC data is in good agreement with results obtained by double electron electron resonance (DEER) spectroscopy. At the same time, the signal-to-noise ratio per shot in DQC is high. Taken together, these results provide impetus for further development of paramagnetic metal ion-based DQC techniques.