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
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
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
Mechanism of glutamate transport from experimental and simulation studies. Glutamate transporters play key roles in shaping the electrical signaling in the brain. Under conditions of stress or after a stroke, glutamate transporter function is impaired, which can lead to excessive levels of glutamate, cell death and impaired brain function. The project will help to decipher the operation of glutamate transporters at a molecular level and provide greater understanding of how glutamate levels are c ....Mechanism of glutamate transport from experimental and simulation studies. Glutamate transporters play key roles in shaping the electrical signaling in the brain. Under conditions of stress or after a stroke, glutamate transporter function is impaired, which can lead to excessive levels of glutamate, cell death and impaired brain function. The project will help to decipher the operation of glutamate transporters at a molecular level and provide greater understanding of how glutamate levels are controlled, which is vital for developing better treatments for neurological disorders such as stroke. The project will also provide research training in experimental/computational molecular biology, which is a rapidly growing field underpinning the biotechnological and pharmaceutical industries. 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
Hierarchical modeling of protein interactions. Protein interactions play a central role in function and structural organization of cells. Their elucidation is essential for a better understanding of many cellular processes from signal transduction to enzyme inhibition. The aim of this project is to utilize the unprecedented powers of current supercomputers in developing a hierarchical model of protein interactions. The method combines Brownian dynamics at large distances and long time scales ....Hierarchical modeling of protein interactions. Protein interactions play a central role in function and structural organization of cells. Their elucidation is essential for a better understanding of many cellular processes from signal transduction to enzyme inhibition. The aim of this project is to utilize the unprecedented powers of current supercomputers in developing a hierarchical model of protein interactions. The method combines Brownian dynamics at large distances and long time scales with molecular dynamics at small distances and shorter times. Applications to both membrane proteins (blocking of ion channels by toxins and drugs) and globular proteins (ligand binding to receptors and protein association) will be considered.Read moreRead less