Understanding the molecular mechanism of force generation in the bacterial flagellar motor. The proposed research will advance the knowledge about how the bacterial flagellar motor works, enabling scientists to learn more about nature's blueprint of a nanoscale engine. It will address the fundamental question of how bacterial cells convert electrochemical energy into mechanical energy of rotation. At present, the smallest artificial electric motor is still on a micro-, rather than nanoscale. Nan ....Understanding the molecular mechanism of force generation in the bacterial flagellar motor. The proposed research will advance the knowledge about how the bacterial flagellar motor works, enabling scientists to learn more about nature's blueprint of a nanoscale engine. It will address the fundamental question of how bacterial cells convert electrochemical energy into mechanical energy of rotation. At present, the smallest artificial electric motor is still on a micro-, rather than nanoscale. Nanotechnology would therefore benefit from this work by basing their designs on the principles behind the mechanism of the bacterial motor. This research is also of interest for veterinary science, as motility by flagellar motor is a key virulence factor of common animal pathogens associated with, for example, listeriosis and gastroenteritis.Read moreRead less
In situ measurements of the electrostatic properties inside photosynthetic reaction centres: correlation with the energy conversion function of the protein. The photochemical reaction centre is a key protein complex involved in energy conversion. It converts solar energy into chemical energy as a transmembrane charge separation. Coupling of electron and proton transfer is catalysed at the level of a ubiquinone cofactor. In order to understand how the redox properties of this cofactor are fine tu ....In situ measurements of the electrostatic properties inside photosynthetic reaction centres: correlation with the energy conversion function of the protein. The photochemical reaction centre is a key protein complex involved in energy conversion. It converts solar energy into chemical energy as a transmembrane charge separation. Coupling of electron and proton transfer is catalysed at the level of a ubiquinone cofactor. In order to understand how the redox properties of this cofactor are fine tuned by the protein environment, we plan to probe the ubiquinone site using a voltage-sensitive fluorescent dye. This exciting multidisciplinary project will contribute to the understanding of how protein matrices influence and govern the midpoint redox potential of their cofactors and the environments of theirRead moreRead less
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
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
From structures to systems: A hierachical approach to understanding sub-cellular components. This program will dramatically extend the range of biomolecular systems that can be modelled with near atomistic precision. It will provide a better understanding of the structure and function of proteins involved in the regulation of membrane fusion and fission as well as shedding light on the assembly of large-scale protein-protein and protein-membrane complexes in general. The work will help place Au ....From structures to systems: A hierachical approach to understanding sub-cellular components. This program will dramatically extend the range of biomolecular systems that can be modelled with near atomistic precision. It will provide a better understanding of the structure and function of proteins involved in the regulation of membrane fusion and fission as well as shedding light on the assembly of large-scale protein-protein and protein-membrane complexes in general. The work will help place Australia at the forefront of developing simulation techniques in biomolecular systems, which are widely used within the chemical and pharmaceutical industries for modelling processes ranging from protein-drug interactions to the phase behaviour of lipids and surfactants. Read moreRead less
A rational approach to a high-resolution structure of the multidrug transporter EmrE. Membrane proteins form only 0.3% of the available protein structures in the protein data bank (PDB), yet 30% of the proteins in the human genome and 50% of human drug targets are membrane proteins. Multidrug transporters are membrane proteins responsible for antibiotic resistance in humans. A high-resolution structure of a multidrug resistance protein, together with comprehensive biochemical characterization, w ....A rational approach to a high-resolution structure of the multidrug transporter EmrE. Membrane proteins form only 0.3% of the available protein structures in the protein data bank (PDB), yet 30% of the proteins in the human genome and 50% of human drug targets are membrane proteins. Multidrug transporters are membrane proteins responsible for antibiotic resistance in humans. A high-resolution structure of a multidrug resistance protein, together with comprehensive biochemical characterization, would enable a detailed understanding of how these protein functions. Potentially it could also aid in the development of specific inhibitors that would prevent EmrE (and perhaps other similar proteins) from carry out its harmful mission. 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
Molecular structure and function of the glycine receptor. This proposal will employ a cutting edge approach to reveal fundamental new insights into the ways that ligand-gated ion channels, and proteins in general, work. The new knowledge and technology developed here will broaden and strengthen Australia's research expertise across a number of basic scientific disciplines. The results will also have relevance to human health. Glycine receptors have an essential role in brain function and are ....Molecular structure and function of the glycine receptor. This proposal will employ a cutting edge approach to reveal fundamental new insights into the ways that ligand-gated ion channels, and proteins in general, work. The new knowledge and technology developed here will broaden and strengthen Australia's research expertise across a number of basic scientific disciplines. The results will also have relevance to human health. Glycine receptors have an essential role in brain function and are targets for anaesthetics and drugs of abuse. GlyRs are also important in modulating pain sensation by the brain. New insights into how natural agonists and drugs affect ion channel structure and function may lead to novel therapeutic opportunities and improved drug structure predictions.Read moreRead less
Quantum mechanical and dynamical investigation of ion channels. Many genetic diseases result from mutations in the genes that transcribe the channel proteins. Ion channels are also primary targets for development of therapeutic drugs for many ailments. Development of proper simulation tools is essential for a molecular-level understanding of their operation, which will be very helpful in finding treatments for genetic diseases as well as new drugs that target ion channels. Another aim of the p ....Quantum mechanical and dynamical investigation of ion channels. Many genetic diseases result from mutations in the genes that transcribe the channel proteins. Ion channels are also primary targets for development of therapeutic drugs for many ailments. Development of proper simulation tools is essential for a molecular-level understanding of their operation, which will be very helpful in finding treatments for genetic diseases as well as new drugs that target ion channels. Another aim of the project is to provide research training in computational biology. Research in this area is rapidly growing elsewhere but it has been rather neglected in Australia, and there is a shortage of researchers with such skills at present.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