TOMOKO OHNISHI, Ph.D.
Professor of Biochemistry and Biophysics
214A Anatomy-Chemistry Building/5059
T: (215) 898-8024, 898-2939
F: (215) 573-3748
Ph.D. National Nagoya University (1962)
DESCRIPTION OF RESEARCH INTERESTS:
Research projects of Dr. Ohnishi's laboratory focus on structure/function studies of the NADH-quinone oxidoreductase (also known as complex I) in both prokaryotic and eukaryotic systems. This is the largest and important enzyme which contains 8 or 9 iron-sulfur clusters, one non-covalently bound FMN, and 2 protein-bound quinone species. The laboratory's major interest is to examine the molecular mechanism of the coupling between electron and proton transfer in this enzyme. In 2005, this laboratory published a novel conformation-driven semiquinone-gated proton pumping mechanism.
As basic techniques in the laboratory, electron paramagnetic resonance, optical spectroscopies and redox potentiometry are used. Extensive collaborations are conducted with other laboratories having expertise in molecular biology or other spectroscopic techniques such as electron nuclear double resonance (ENDOR), electron spin-echo (ESE), as well as Fourier transform infrared (FTIR) spectroscopies.
The Ohnishi lab is also studying medically relevant reactive oxygen and nitric oxide radicals in the NADH-quinone oxidoreductase reactions, using spin-trapping techniques.