Mechanosensitive properties and modulation of N-methyl-D-aspartate (NMDA) receptors by lipid environment. This project will provide new information about the molecular determinants which influence NMDA receptor channel gating that will significantly advance our understanding of a link between NMDA receptor function and many neurodegenerative diseases as well as pain and learning and memory. The outcomes of this project may lead to the discovery of novel lipid-based biomaterials for application i ....Mechanosensitive properties and modulation of N-methyl-D-aspartate (NMDA) receptors by lipid environment. This project will provide new information about the molecular determinants which influence NMDA receptor channel gating that will significantly advance our understanding of a link between NMDA receptor function and many neurodegenerative diseases as well as pain and learning and memory. The outcomes of this project may lead to the discovery of novel lipid-based biomaterials for application in medicine and the drug industry. This research is highly significant in relation to human health. The biological and nutritional aspects of polyunsaturated lipids and dietary fish oils have long been recognized. Thus this project will provide further knowledge that could benefit the health of the nation with consequent reduced health care costs.Read moreRead less
Disorder as a novel determinant of photosynthetic structure and function: an experimental study. Australia enjoys a world reputation in photosynthesis research, typified by hosting the 2001 International Photosynthesis Congress. It also has a claim to fame for theoretical work in non-equilibrium thermodynamics concerning production of disorder or entropy, yielding new insights into planetary climates. This experimental project investigates the novel relation between entropy/entropy production ....Disorder as a novel determinant of photosynthetic structure and function: an experimental study. Australia enjoys a world reputation in photosynthesis research, typified by hosting the 2001 International Photosynthesis Congress. It also has a claim to fame for theoretical work in non-equilibrium thermodynamics concerning production of disorder or entropy, yielding new insights into planetary climates. This experimental project investigates the novel relation between entropy/entropy production and the structure/function of the solar powerhouse of plants (chloroplasts), and addresses fundamental questions at the interface of biology and physics. The research explores chloroplasts as a manifestation of the all-pervading Second Law of Thermodynamics, advancing Australia's contribution to basic science and helping to train researchers.Read moreRead less
Oxidative stress-induced alterations of the host erythrocyte by the malaria parasite. The malaria parasite spends part of its lifecycle inside the red blood cells of its host. During this time, the parasite modifies many of the features of the red blood cell and subjects it to high levels of oxidative stress. We will use and develop a variety of fluorescence and microscopic techniques to understand the molecular basis of the alterations in the organization of membrane proteins in malaria parasit ....Oxidative stress-induced alterations of the host erythrocyte by the malaria parasite. The malaria parasite spends part of its lifecycle inside the red blood cells of its host. During this time, the parasite modifies many of the features of the red blood cell and subjects it to high levels of oxidative stress. We will use and develop a variety of fluorescence and microscopic techniques to understand the molecular basis of the alterations in the organization of membrane proteins in malaria parasite-infected red blood cells. We will examine the roles of oxidative stress and of parasite proteins in modulating the properties of the host cell membrane.Read moreRead less
Probing membrane rafts using surface-selective multi-dimensional microscopy. The results of this project will provide fundamental insights into the role played by domains in cell membranes in the regulation of membrane protein function. These insights will create new avenues in the biotechnology industry for development of novel therapeutics aimed at disruption of membrane protein-protein interactions that cause aberant cell signalling in disease states such as cancer.
The role of mechanosensitive (MS) ion channels in magnetoreception. The magnetic field of the Earth has for long been known to influence the behaviour and orientation of a variety of organisms. Experimental study of the magnetic sense has however, been impaired by the lack of a plausible cellular and/or molecular mechanism providing meaningful explanation for detection of magnetic fields by living organisms. Recently, mechanosensitive (MS) ion channels have been implied to play a role in magneto ....The role of mechanosensitive (MS) ion channels in magnetoreception. The magnetic field of the Earth has for long been known to influence the behaviour and orientation of a variety of organisms. Experimental study of the magnetic sense has however, been impaired by the lack of a plausible cellular and/or molecular mechanism providing meaningful explanation for detection of magnetic fields by living organisms. Recently, mechanosensitive (MS) ion channels have been implied to play a role in magnetoreception. Based on our preliminary investigations, which suggest that the activity of bacterial MS channels may be affected by magnetic fields, we propose to study effects of magnetic fields on MS ion channels in Gram-negative bacteria Escherichia coli and Magnetospirillum magnetotacticum. The project promises also to contribute towards better understanding of adverse effects of electromagnetic radiation on human health and towards understanding the mechanisms behind remote magnetic-nanoparticle mediated activation of MS ion channels.Read moreRead less
Monolayer crystallization of membrane proteins. Membrane proteins comprise 25-40% of all proteins and conduct a myriad of finely tuned reactions in every cell. Despite their importance and diversity only ~40 membrane protein structures have been solved, due to the difficulty of producing high quality 2D and 3D crystals. We propose to develop and use the new monolayer crystallization technique, which employs a lipid monolayer as a crystallization template for 2D crystal production. A number of ....Monolayer crystallization of membrane proteins. Membrane proteins comprise 25-40% of all proteins and conduct a myriad of finely tuned reactions in every cell. Despite their importance and diversity only ~40 membrane protein structures have been solved, due to the difficulty of producing high quality 2D and 3D crystals. We propose to develop and use the new monolayer crystallization technique, which employs a lipid monolayer as a crystallization template for 2D crystal production. A number of important membrane proteins are available for these structural studies including ABC transporters, Caveolin-3 and the NS1 protein of Dengue virus, all of which are difficult to crystallize using conventional techniques.Read moreRead less
Characterisation of two-pore domain potassium channels: structure-function studies of the M1-P1 loops of TASK channels. TWIK-related Acid Sensitive K+ (TASK) channels are members of the novel class of two-pore domain potassium channel family. They are potently inhibited by local anaesthetics and have been implicated as having important roles in many pathophysiological conditions such as heart arrythmias, stroke, epilepsy, breast and other cancers. The in depth structural and functional character ....Characterisation of two-pore domain potassium channels: structure-function studies of the M1-P1 loops of TASK channels. TWIK-related Acid Sensitive K+ (TASK) channels are members of the novel class of two-pore domain potassium channel family. They are potently inhibited by local anaesthetics and have been implicated as having important roles in many pathophysiological conditions such as heart arrythmias, stroke, epilepsy, breast and other cancers. The in depth structural and functional characterisation of this class of potassium channels is of great importance as they are interesting targets for new therapeutic developments. Advancement of knowledge in the structure and function of these channels will underpin drug targeting that will aid preventative healthcare, allowing Australians to age well and age productively.Read moreRead less
Electro-active and migratory peptides in lipid bilayers: NMR and biophysical studies. All living things are characterized by the separation of inner space from the surrounding medium by a self-assembling membrane. Selective entry and exit of water, ions and solutes is a defining feature of each type of cell. Some proteins sense the voltage difference across the cell membrane and open or close in response to voltage changes. Others, like bacterial toxins assemble in the membrane as pores, while o ....Electro-active and migratory peptides in lipid bilayers: NMR and biophysical studies. All living things are characterized by the separation of inner space from the surrounding medium by a self-assembling membrane. Selective entry and exit of water, ions and solutes is a defining feature of each type of cell. Some proteins sense the voltage difference across the cell membrane and open or close in response to voltage changes. Others, like bacterial toxins assemble in the membrane as pores, while other peptides migrate across the membrane piggy-backing their peptide cargo. The aim is to understand the molecular mechanisms in examples of these membrane-active peptides and proteins with a view to enabling rational intervention into their operation in situ in normal and disease states.Read moreRead less
NMR studies of membrane proteins and peptides in novel amphiphilic mesophases. Membrane proteins are the next frontier in structural biology. Our goal is the structural and mechanistic characterization of the proteins and peptides from platypus venom and a cardiac potassium ion channel, HERG, that has a particular role in the suppression of cardiac arrhythmias. To do this we will refine and develop methods using amphiphilic mesophases and micelles and state-of-the-art NMR spectroscopy. Electrop ....NMR studies of membrane proteins and peptides in novel amphiphilic mesophases. Membrane proteins are the next frontier in structural biology. Our goal is the structural and mechanistic characterization of the proteins and peptides from platypus venom and a cardiac potassium ion channel, HERG, that has a particular role in the suppression of cardiac arrhythmias. To do this we will refine and develop methods using amphiphilic mesophases and micelles and state-of-the-art NMR spectroscopy. Electrophysiological analysis of ion channels and interactions with toxins will relate NMR structures to function. The NMR methodologies we develop will have broad applicability to membrane proteins in general.
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Realistic models of permeation in ion channels. Ion channels are formed by proteins in cell membranes and provide pathways for fast and controlled flow of selected ions. This activity generates action potentials in nerves and muscles that forms the basis of all movement, sensation and thought processes. Recent determination of the crystal structure of channel proteins has enabled construction of models that can relate channel function to its structure--necessary for understanding their operati ....Realistic models of permeation in ion channels. Ion channels are formed by proteins in cell membranes and provide pathways for fast and controlled flow of selected ions. This activity generates action potentials in nerves and muscles that forms the basis of all movement, sensation and thought processes. Recent determination of the crystal structure of channel proteins has enabled construction of models that can relate channel function to its structure--necessary for understanding their operation and seeking cures for diseases caused by their malfunction. This project aims to develop accurate ion-protein-water interactions for permeation models based on stochastic and molecular dynamics simulations using both classical and quantum mechanical methods.Read moreRead less