Dr. Donald J. Hirsh
B.S., Stanford University
Ph.D., Yale University
Postdoctoral Research Associate, Washington University
Dr. Michelle Bunagan, Dr. Joseph Baker, and I teach the physical chemistry sequence: Quantum Chemistry and Chemical Thermodynamics. I also teach General Chemistry I and II. I use and am an advocate for guided inquiry and active teaching methods.
Measurement of Nanometer-scale Distances and Weak Exchange Couplings using Electron Paramagnetic Resonance (EPR) Spectroscopy. Typically, electrons are found “paired” in atomic or molecular orbitals and so we do not observe their magnetic properties. However, radicals and many metal ions have unpaired electrons and these have an observable magnetic dipole moment, like that of a bar magnet or compass needle. We have shown that distances can be measured in chemically modified DNA duplexes using the magnetic interactions between radicals and metal ions and EPR spectroscopy. We are currently working on precise distance measurements within proteins in collaboration with Dr. Hunt‘s lab.
Nitric Oxide Production in Mammals and Phytoplankton. Nitric oxide, the simple diatomic molecule NO, serves many roles in animal and plant physiology. It stimulates vasodilation and neurotransmission and, at high concentrations, kills pathogens. We have developed a new method to detect nitric oxide production using a liposome-encapsulated spin trap. We are using this new method to better understand the production of nitric oxide by the enzyme inducible nitric oxide synthase. We are also working in collaboration with Dr. Kay Bidle‘s lab at Rutgers to understand the mechanisms and genetics of nitric oxide production in two types of phytoplankton: diatoms and coccolithophores.
(TCNJ undergraduate researchers underlined.)
A Liposome-Encapsulated Spin Trap for the Detection of Nitric Oxide, Hirsh, D. J.; Schieler, B. M.; Fomchenko, K. M.; Jordan, E. T.; Bidle, K. D. (2016) Free Radical Biology and Medicine , 96, 199-210
Saturation Recovery EPR with Nitroxyl Radical – Dy(III) Spin Pairs: Distances and Orientations, Hirsh, D. J., McCracken, J. M., Biczo, R., and Gesuelli, K.-A., (2013) Journal of Physical Chemistry B, 117: 11960–11977
Sensitivity Enhancement in Continuous-Wave Electron Paramagnetic Resonance: Adaptive Signal Averaging versus a Moving Average, Brinton, Christopher G. and Hirsh, D. J., (2010) Review of Scientific Instruments 81(2)
Structure and Dynamics of a DNA-based Model System for the Study of Electron Spin-spin Interactions, Biczo, R. and Hirsh, D. J., (2009) Journal of Inorganic Biochemistry 103: 362-372
A Diatom Gene Regulating Nitric-oxide Signaling and Susceptibility to Diatom-derived Aldehydes, Vardi, A., Bidle, K. D., Kwityn, C., Hirsh, D. J., Thompson, S. M., Callow, J. A., Falkowski, P. and Bowler, C., (2008) Current Biology 18: 895-899
Measuring Distances in Proteins by Saturation-Recovery EPR, Hirsh, D. J. and Brudvig, G. W., (2007) Nature Protocols 2: 1770-1781
Progress Towards a DNA-based Model System for Studying Electron Spin-Spin Interactions,Chen, X.J., Szklarski, R.A., Tuohy, C., Schramm, J., Skiff, H., Hummel, K, Vacirca, N., Wolf, B. A., and Hirsh, D.J., (2007) Biophysical Chemistry 129: 148-162