title: L-band Overhauser dynamic nuclear polarization.
abstract: We present the development of an Overhauser dynamic nuclear polarization (DNP) instrument at 0.04 T using 1.1 GHz (L-band) electron spin resonance frequencies (ESR) and 1.7 MHz (1)H nuclear magnetic resonance frequencies. Using this home-built DNP system, the electron-nucleus coupling factor of 4-oxo-TEMPO dissolved in water was determined as 0.39+/-0.06 at 0.04 T. The higher coupling factor obtained at this field compared to higher magnetic fields, such as 0.35 T, directly translates to higher enhancement of the NMR signal and opens up a wider time scale window for observing water dynamics interacting with macromolecular systems, including proteins, polymers or lipid vesicles. The higher enhancements obtained will facilitate the observation of water dynamics at correlation times up to 10 ns, that corresponds to more than one order of magnitude slower dynamics than accessible at 0.35 T using X-band ESR frequencies.
authors.affiliation: Department of Food Science & Technology, University of California, Davis, CA 95616, USA. spgarcia24@gmail.com
authors.forename: Sandra
authors.initials: S
authors.lastname: Garcia
authors.forename: Jeffrey H
authors.initials: JH
authors.lastname: Walton
authors.forename: Brandon
authors.initials: B
authors.lastname: Armstrong
authors.forename: Songi
authors.initials: S
authors.lastname: Han
authors.forename: Michael J
authors.initials: MJ
authors.lastname: McCarthy
mesh_terms: D000465:Algorithms; D003497:Cyclic N-Oxides / Q000737:chemistry; D003627:Data Interpretation, Statistical; D004574:Electromagnetic Fields; D004578:Electron Spin Resonance Spectroscopy / Q000295:instrumentation*; D004867:Equipment Design; D005609:Free Radicals / Q000737:chemistry; D008055:Lipids / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy / Q000295:instrumentation*; D011506:Proteins / Q000737:chemistry; D014867:Water
chemical_list: D003497:Cyclic N-Oxides; D005609:Free Radicals; D008055:Lipids; D011506:Proteins; D014867:Water; C003959:TEMPO