title: Nitroxide Spin-Labelling and Its Role in Elucidating Cuproprotein Structure and Function.
abstract: Copper is one of the most abundant biological metals, and its chemical properties mean that organisms need sophisticated and multilayer mechanisms in place to maintain homoeostasis and avoid deleterious effects. Studying copper proteins requires multiple techniques, but electron paramagnetic resonance (EPR) plays a key role in understanding Cu(II) sites in proteins. When spin-labels such as aminoxyl radicals (commonly referred to as nitroxides) are introduced, then EPR becomes a powerful technique to monitor not only the coordination environment, but also to obtain structural information that is often not readily available from other techniques. This information can contribute to explaining how cuproproteins fold and misfold. The theory and practice of EPR can be daunting to the non-expert; therefore, in this mini review, we explore how nitroxide spin-labelling can be used to help the inorganic biochemist gain greater understanding of cuproprotein structure and function in vitro and how EPR imaging may help improve understanding of copper homoeostasis in vivo.
authors.affiliation: The School of Science and Health, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2759, Australia. c.jones@westernsydney.edu.au.
authors.forename: Christopher E
authors.identifier: http://orcid.org/0000-0002-8032-7606
authors.initials: CE
authors.lastname: Jones
authors.affiliation: Department of Chemistry and Biochemistry, University of Denver, Denver, CO, 80208-0183, USA.
authors.forename: Lawrence J
authors.initials: LJ
authors.lastname: Berliner
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D004578:Electron Spin Resonance Spectroscopy; D029968:Escherichia coli Proteins / Q000737:chemistry*; D046032:Microscopy, Energy-Filtering Transmission Electron; D018832:Molecular Chaperones / Q000737:chemistry*; D009589:Nitrogen Oxides / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry*; D017510:Protein Folding; D013113:Spin Labels; D013194:Staining and Labeling / Q000379:methods; D015534:Trans-Activators / Q000737:chemistry*
chemical_list: D001426:Bacterial Proteins; C092379:CopZ protein, Enterococcus hirae; D029968:Escherichia coli Proteins; D018832:Molecular Chaperones; D009589:Nitrogen Oxides; D010455:Peptides; D013113:Spin Labels; D015534:Trans-Activators; C489822:cueR protein, E coli; D003300:Copper; C039900:nitroxyl
keywords: Aminoxyl; Copper; Electron paramagnetic resonance; Neurokinin; Nitroxide; Peptide; Protein