Current position
Senior Fellow (Group Leader)
Laboratory Section Head, Oxygenic Photosynthesis
Research interests
The photosynthetic production of oxygen by green plants is the
primary source of the atmospheric oxygen and is essential for
all aerobic life on earth. The process takes place in a highly
specialized, chlorophyll-containing protein complex called photosystem
II. In the formation of O2, water is oxidized in a four-step reaction
sequence at a unique manganese-containing site, providing the
protons and electrons that are ultimately used in carbon assimilation.
My research in the Photobioenergetics Group focuses on the understanding
of photosystem II and the mechanism of O2 evolution.
Some of the experimental approaches that we employ in our studies
include:
(1) mass spectrometric measurements of rapid (ms time-range) oxygen
isotope exchange reactions in photosystem II, for the determination
of the binding parameters for the substrate water and mechanism
of O-O bond formation;
(2) time-resolved, light-minus-dark difference Fourier transform
infrared (FTIR) spectroscopy, for the investigation of the redox-active
components in photosystem II;
(3) electron paramagnetic resonance (EPR) spectroscopy, for monitoring
organic radicals and the catalytic manganese cluster.
In an associated research project we are also attempting to
mimic various aspects of photosystem II structure and function
through the molecular engineering of minimalistic peptides (both
natural and man-made), as part of a broader program in artificial
photosynthesis and renewable energy (Molecular Biofuels).
More recently, in a new research venture with colleagues at
Princeton University and the Russian Academy of Sciences, we have
begun research into the evolutionary biology of oxygenic photosynthesis.
This project is funded by a Human Frontier Scientific Program
Grant and encompasses mechanistic studies of the oxygen evolving
process in relation to the biogeochemistry of the earth and the
photosynthesis of organisms living in extreme environments.
In all of the above studies highly purified samples are prepared
from higher plants, directed mutants of cyanobacteria, and E.
coli over-expression strains using the latest techniques in molecular
biology and biochemistry.
Principle collaborators in our research include: Dr. Ron Pace
and Dr. Gad Fischer, Department of Chemistry, ANU; Dr. Elmars
Krausz, Research School of Chemistry, ANU; Dr. Julian Eaton-Rye,
Department of Biochemistry, University of Otago, New Zealand;
Dr. Charles Dismukes, Department of Chemistry, Princeton University,
U.S.A.; Dr. Vyacheslav Klimov, Institute for Basic Biological
Problems, Russian Academy of Sciences
Selected Publications
Hendry G and Wydrzynski T (2003) 18O isotope exchange measurements
reveal that calcium is involved in the binding of one substrate-water
molecule to the oxygen-evolving complex in photosystem II. Biochemistry
42, 6209-6217
Fischer, G. & Wydrzynski, T. (2001) Isotope effects in FTIR
difference spectra of the photosynthetic oxygen-evolving catalytic
site determined by ab initio calculations on model compounds.
J. Phys. Chem. B 105, 12894-12901.
Hillier, W. & Wydrzynski T. (2001) Oxygen ligand exchange
at metal sites - implications for the O2
evolving mechanism of photosystem II. Biochim. Biophys. Acta 1503,
197-209.
Hillier, W. & Wydrzynski, T. (2000) The affinities for the
two substrate water binding sites in the O2 evolving
complex ofphotosystem II vary independantly during S-state turnover.
Biochemistry 39, 4399-4405.
Zhang, H., Fischer, G. & Wydrzynski T. (1998) Room-temperature
vibrational difference spectrum for S2QB-/S1QB of photosystem
II determined by time-resolved Fourier transform infrared spectroscopy.
Biochemistry 37, 5511-5517.
Wydrzynski, T., Hillier, W. & Messinger, J. (1996) On the
functional significance of substrate accessibility in the photosynthetic
water oxidation mechanism. Physiol. Plant. 96, 342-350.
Further publications
Curriculum Vitae
Education
1977 Phd - University of Illinois at Urbana/Champaign, USA
1969 BA - University of Missouri at St. Louis, USA
Professional Experience
1991-present Fellow/Senior Fellow, Research School of Biological
Sciences, The Australian National University, Canberra, AUSTRALIA
1985-1991 Staff Scientist, Max Volmer Institute for Physical
and Biophysical Chemistry, Technical University Berlin, GERMANY
1980-1984 Research Chemist, Biotechnology Division, Corporate
Research, AMOCO Corporation (Standard Oil Company Indiana), USA
1977-1979 Research Associate, Laboratory of Chemical Biodyanamics,
Lawrence Berkeley Laboratory, USA
Research Fellowships and Grants
2002- Human Frontier Science Program Grant, FRANCE
1998- Australian Research Council Large Grant, AUSTRALIA
1997- National Institute for Basic Biology Fellow, JAPAN
1996- Australian Research Council Large Grant, AUSTRALIA
1995- Australian Research Council International Research Fellowship
Grant,
1989- German Research Organization (DFG) Grant, GERMANY
1986- Wenner Gren Foundation Fellow, SWEDEN
1985- Science and Technology Agency Fellow, JAPAN
1985- Alexander von Humboldt Foundation Fellow, GERMANY
1977- National Science Foundation Fellow, USA
Other Professional Activites
Co-editor, with Kimiyuki Satoh, of the first comprehensive book
on “Photosystem II: The Water/Platoquinone Oxido-Reductase
in Photosynthesis”, to be published in 2004 by Kluwer Academic
Publishers in the Advances in Photosynthesis and Respiration series
Tentative
Table of Contents for the Photosystem II Book (PDF file)
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