Oxygen and Water Channels in Proteins
Proteins often catalyse reactions that are
remarkably efficent. Indeed compared to some industrial catalysts
enzymes are remarkable in that they operate at atmospheric pressure,
neutral pH, room temperature and with low substrate concentrations.
Part of this remarkable efficency is born out by substrate channels in
the enzymes that direct and orcestrate the chemical reaction, transition
state intermediate and the release and removal of the product.
The Photosystem II enzyme intakes H2O and oxidises it to O2 while cytochrome c oxidase intakes O2and reduces it to H2O. The 4-electron oxidation and reduction reactions are very carefully controlled to minimise any hazardous production of reactive oxygen species (ROS). In these enzymes substrate entry and product exit is channeled into and out of a buried catalytic site. We are interested in developing a project to study the channels and substrate access in PSII and other proteins. This project will involve mutagenesis studies, spectroscopy and computational analysis of substrate and product trajectories through the protein matrix.
Examples
Murray, J.A and Barber, J (2007) Structural characteristics of channels and pathways in photosystem II including the identification of an oxygen channel. Journal of Structural Biology 159, 228–237. <link>
Ho, F.M and Styring, S (2008) Access channels and methanol binding site to the CaMn4 cluster in Photosystem II based on solvent accessibility simulations, with implications for substrate water access. Biochim Biophys Acta 1777, 140–153. <link>
The Photosystem II enzyme intakes H2O and oxidises it to O2 while cytochrome c oxidase intakes O2and reduces it to H2O. The 4-electron oxidation and reduction reactions are very carefully controlled to minimise any hazardous production of reactive oxygen species (ROS). In these enzymes substrate entry and product exit is channeled into and out of a buried catalytic site. We are interested in developing a project to study the channels and substrate access in PSII and other proteins. This project will involve mutagenesis studies, spectroscopy and computational analysis of substrate and product trajectories through the protein matrix.
Examples
Murray, J.A and Barber, J (2007) Structural characteristics of channels and pathways in photosystem II including the identification of an oxygen channel. Journal of Structural Biology 159, 228–237. <link>
Ho, F.M and Styring, S (2008) Access channels and methanol binding site to the CaMn4 cluster in Photosystem II based on solvent accessibility simulations, with implications for substrate water access. Biochim Biophys Acta 1777, 140–153. <link>
Supervisor profile: http://biology.anu.
Contact: warwick.hillier(at)anu.edu.au
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