Spectroscopic selection of distance measurements in a protein dimer with mixed nitroxide and Gd3+ spin labels

• Published in: Physical chemistry chemical physics : PCCP Vol. 14; no. 13; pp. 4355 - 4358
• Main Authors: Kaminker, Ilia, Yagi, Hiromasa, Huber, Thomas, Feintuch, Akiva, Otting, Gottfried, Goldfarb, Daniella
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 07.04.2012
• Subjects: Chemistry; Dimerization; Electron Spin Resonance Spectroscopy; Exact sciences and technology; Gadolinium - chemistry; General and physical chemistry; Heat-Shock Proteins - chemistry; Models, Molecular; Molecular Structure; Nitrogen Oxides - chemistry; Spin Labels; Data analysis; Selection; Pulse; Ions; Biological macromolecule; Potential; Protein; Double resonance methods; Spin label; Distribution; High field; Dimer; Distance measurement; Electrons
• ISSN: 1463-9076; 1463-9084; 1463-9084
• DOI: 10.1039/c2cp40219j

The pulse DEER (Double Electron-Electron Resonance) technique is frequently applied for measuring nanometer distances between specific sites in biological macromolecules. In this work we extend the applicability of this method to high field distance measurements in a protein assembly with mixed spin labels, i.e. a nitroxide spin label and a Gd(3+) tag. We demonstrate the possibility of spectroscopic selection of distance distributions between two nitroxide spin labels, a nitroxide spin label and a Gd(3+) ion, and two Gd(3+) ions. Gd(3+)-nitroxide DEER measurements possess high potential for W-band long range distance measurements (6 nm) by combining high sensitivity with ease of data analysis, subject to some instrumental improvements.