Bacterial antibiotic resistance is mediated through specific biological molecules, so-called multidrug transporter proteins, which effectively export drugs from the cell. This proposal aims to solve the 3D structure of a multidrug resistance protein, NorM, which confers resistance to fluoroquinolone type drugs. Through this, we will provide detail into transport across the membrane of cells, and thus present a molecular understanding of bacterial antibiotic resistance.
Investigation Of Biological Ion Channels: Theoretical Formulation, Computer Simulation And Experimental Verification
Funder
National Health and Medical Research Council
Funding Amount
$677,292.00
Summary
All electrical activities in the brain are regulated by opening and closing of ion channels. Thus, undertanding their mechanisms at a molecular level is a fundamental problem in neurobiology. There are many different types of ion channels, each type fulfilling a different role. For the first time, a group of American scientists have determined the shape of one type of ion channels. Using this newly unveiled information, we propose to build a mathematical theory of ion channels. And then, making ....All electrical activities in the brain are regulated by opening and closing of ion channels. Thus, undertanding their mechanisms at a molecular level is a fundamental problem in neurobiology. There are many different types of ion channels, each type fulfilling a different role. For the first time, a group of American scientists have determined the shape of one type of ion channels. Using this newly unveiled information, we propose to build a mathematical theory of ion channels. And then, making use of a powerful supercomputer, we propose to follow the motion of ions as they move through the channel, study how a channel can select only the correct type of ions to traverse it and determine how many ions a single channel is capable of processing per second. The predictions made by our theory and computer simulations will be checked experimentally. If the predictions and experimental findings do not agree, we will modify the theory and make new predictions.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
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
Characterisation And Regulation Of Chloride Channels In Cardiac And Skeletal Sarcoplasmic Reticulum In Mammals
Funder
National Health and Medical Research Council
Funding Amount
$381,856.00
Summary
An understanding of the operation of ion channels in cell membranes is fundamental to our knowledge of the function of muscles under normal conditions and in pathological states that modify cell function, e.g. myotonia and cardiac failure. Ion channels control the flow of currents and the transport of substances which ultimately determine whether cells live or die, and hence whether cell pathologies are expressed as muscle failure, as when hypoxia causes tissue damage to the heart, or as severe ....An understanding of the operation of ion channels in cell membranes is fundamental to our knowledge of the function of muscles under normal conditions and in pathological states that modify cell function, e.g. myotonia and cardiac failure. Ion channels control the flow of currents and the transport of substances which ultimately determine whether cells live or die, and hence whether cell pathologies are expressed as muscle failure, as when hypoxia causes tissue damage to the heart, or as severe arrythmia or cardiac arrest. The objective is to understand channel involvement in the mechanisms underlying the function of cardiac and skeletal muscle. We believe that by mimicking the factors that occur in pathological conditions we can understand how ion channels are altered and controlled, and find ways of reversing harmful alterations, thereby reversing cell damage and failure of vital muscle function.Drugs will be used to modify the 'gating' of the channels. By comparing the effects of different drugs, we hope to determine the important features of the mechanisms that control the gating of the channels, making them more or less sensitive to different influences, especially those that occur in pathological states. The study has great application to the study of other pathologies, e.g. cystic fibrosis, severe diarrhoea, paralysis and chronic fatigue. The pharmacological emphasis offers the fundamental science needed to design novel and specific drugs to combat the many serious pathologies related to ion channel effects. Aside from its importance to basic science and to immediate issues of health, the study offers considerable economic gains, both through improved public health and through development of pharmaceuticals.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
Linkage Infrastructure, Equipment And Facilities - Grant ID: LE0775613
Funder
Australian Research Council
Funding Amount
$467,000.00
Summary
Automated Patch Clamp System. Ion channels are membrane proteins that underlie cell function and are therefore important drug targets. The patch clamp technique is the most powerful tool available to study the function of single ion channels. The recent automation of this technology represents a quantum leap in our ability to perform high throughput screening of novel natural and synthetic compounds as drug leads. This will lead to an urgently needed increase in capacity, increasing the volume o ....Automated Patch Clamp System. Ion channels are membrane proteins that underlie cell function and are therefore important drug targets. The patch clamp technique is the most powerful tool available to study the function of single ion channels. The recent automation of this technology represents a quantum leap in our ability to perform high throughput screening of novel natural and synthetic compounds as drug leads. This will lead to an urgently needed increase in capacity, increasing the volume of research and its outcomes, which will benefit the Australian pharmaceutical industry and biosciences research community.
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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