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Current position
Assistant Professor (Fellow)
Research Interests:
My research interests are biochemical/biophysical aspects of metalloproteins. These proteins perform important biological chemistry and derive chemical activity via incorporation of metal cofactors such as Mn, Fe etc. The incorporation of a metal cofactor enables such proteins to perform multi-electron redox chemistry of important reactions. Two areas of interest are the enzymes of photosynthesis and respiration. Using these systems modified artificial proteins that use light energy are being designed.
Objectives of research:
Catalysis based on thermodynamic efficiency:
A compelling feature of many biological catalysis, is their remarkable overall thermodynamic efficiency. This optimisation is the result of evolution (combinatorial chemistry) taking place and biology continually redesigning for chemical efficiency and speed. We use mechanistic insights from natural enzymes to provide design insights and pointers for the creation of de novo proteins or re-engineering other enzymes.
Catalysis based on abundant metals:
Biology has designed many remarkable chemical reactions and the basis has been available earth-abundant metal cofactors. This means future artificial protein catalysts based on these design concepts can be made cheaply.
Water in Proteins:
Biology operates within an aqueous realm. Proteins are stabilised by water and many proteins utilise water internally for structural and chemical roles. We study water binding and exchange in proteins in the Photosystem II protein as this protein must channel substrate water into a reaction site where a unique water splitting reaction proceeds and liberates molecular oxygen. The reaction is rather critical for earth – O2 is essential for complex life on earth. Our studies seek to understand the chemistry of the reaction and how proteins channel or regulate water.
Photosynthetic Processes
There are a number of interesting reactions in Photosynthetic organisms that are studied with instrumentation we have. This includes interconversion of CO2 and bicarbonate by carbonic anhydrase, photochemical efficiency and coupling of the light reactions and the generation of O2 and H2 from photosynthetic tissues.
Research Significance
The conversion of solar energy into chemical energy is the principle reason for life on earth. This reaction is the net capture of energy for the biosphere. The photosynthetic reactions also serve as models or paradigms for artificial systems. The capture of sunlight in photosynthetic reactions at short times (fs-ns-us) is extremely efficient - and indeed sets benchmarks for all solar catalyst. We and other researchers around the world are seeking to developing solar catalysts based on the natural system using Artificial Photosynthesis. We base our designs of model proteins on systems nature has developed and produce these proteins with in vitro expression systems. We will use these systems to harness solar energy and store energy as a chemical bond as H2 and O2. Future demands on energy from humanity and the need for CO2 free fuels provide critical incentives for this type of research.
Approaches
To gain insights into mechanism of these enzymes a variety of techniques are employed emphasising spectroscopy and a biodiversity of biological material. As such understanding how reaction catalysis proceeds: reaction rate, intermediates, specificity, redox potentials and overpotential are all important parameters to discover. The following are snapshots of the technology.
Potential Students
Generally speaking, students or postdocs with related experience or a strong interest in the above areas are encouraged to apply. A number of possible projects are included here <link here>
Selected Publications
Hillier, W. and Wydrzynski, T. (2008) 18O-Water Exchange in Photosystem II: Substrate Binding and Intermediates of the Water Splitting Reaction. Coordination Chemistry Reviews 252, 306-317. http://dx.doi.org/10.1016/j.ccr.2007.09.004
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