The Activation Of Lipoprotein Lipase By Apolipoprotein C-II
Funder
National Health and Medical Research Council
Funding Amount
$250,500.00
Summary
Abnormalities in blood lipid levels are common in our society. Treatment of these conditions adds a heavy burden to national health-care costs. Lipoprotein lipase is a plasma enzyme that plays a central role in maintaining safe blood lipid levels. The action of lipoprotein lipase in subjects on a western diet leads to the hydrolysis of about 150g of plasma triacylglycerol daily. Naturally occurring mutations in lipoprotein lipase, associated with a complete loss of enzyme activity, result in a h ....Abnormalities in blood lipid levels are common in our society. Treatment of these conditions adds a heavy burden to national health-care costs. Lipoprotein lipase is a plasma enzyme that plays a central role in maintaining safe blood lipid levels. The action of lipoprotein lipase in subjects on a western diet leads to the hydrolysis of about 150g of plasma triacylglycerol daily. Naturally occurring mutations in lipoprotein lipase, associated with a complete loss of enzyme activity, result in a high blood-lipids that can lead to premature atherosclerosis. Regulation of lipoprotein lipase occurs via an interaction with the regulatory protein apolipoprotein C-II. Individuals with apolipoprotein C-II deficiency also exhibit abnormal plasma lipid levels with an associated increased risk of coronary heart disease. These considerations demonstrate that the activation of lipoprotein lipase by apolipoprotein C-II is pivotal to the maintenance of normal blood lipid levels. The present proposal will establish the structure and orientation of apolipoprotein C-II in a lipid environment and provide a structural model for the activation of lipoprotein lipase by apolipoprotein C-II. These molecular details will serve as a model for the regulatory interactions of other apolipoproteins within lipoprotein particles and will generate leads for the development of new strategies for the treatment of blood lipid irregularities.Read moreRead less
Characterization Of 72 And 52 KDa Inositol Polyphosphate 5-phosphatases: Role In Vesicular Trafficking And Cell Death
Funder
National Health and Medical Research Council
Funding Amount
$408,055.00
Summary
Cells respond to the external environment, stress, hormones and grow th factors by generating messages inside the cell that send a signal to the nucleus that stimulates cell growth. One such signalling network is that produced by membrane lipids known as phosphoinositides. Enzymes or kinases that modify these membrane lipids in particular an enzyme known as the PI 3-kinase generate potent signalling molecules that regulate cell growth. It has been shown by many studies that signals generated by ....Cells respond to the external environment, stress, hormones and grow th factors by generating messages inside the cell that send a signal to the nucleus that stimulates cell growth. One such signalling network is that produced by membrane lipids known as phosphoinositides. Enzymes or kinases that modify these membrane lipids in particular an enzyme known as the PI 3-kinase generate potent signalling molecules that regulate cell growth. It has been shown by many studies that signals generated by the PI 3-kinase are amplified in certain human cancers. Inherited cancer syndromes have been described in which the cell has lost the ability to switch off these lipid messenger molecules. The current project aims to investigate two recently identified enzymes called 5-phosphases that have the ability to terminate PI 3-kinase membrane signals. Both these enzymes were isolated and characterized by the host laboratory and it is predicted they will play distinct roles in the cell. The 72 kDa 5-phosphatase is predicted to regulate protein and vesicular trafficking to the surface of cell. This proposal aims to investigate if the 72 kDa 5-phosphatase can regulate the intracellular sorting of new proteins within the cell. We have also noted the 72 kDa 5-phosphatase may play a role in the development of the nervous system in particular the ability of nerves to send branches out and differentiate. This proposal will investigate this hypothesis. The second enzyme that we have isolated is a 52 kDa 5-phosphatase. This enzyme is present in many cells. We have compelling evidence that the enzyme forms a complex with a recently decribed protein called SODD that stops cells from dying in response to inappropropirate signals. We predict the 52 kDa 5-phosphatase may function to prevent prolonged cell survival as is observed in cancer. We will investigate if this enzyme regulates the cell death pathway and if increased or decreased levels of the 52 kDa 5-phosphatase alter cell survivalRead moreRead less
Targeting Redox Homeostasis To Prevent Mycobacterium Tuberculosis Persistence
Funder
National Health and Medical Research Council
Funding Amount
$396,025.00
Summary
Tuberculosis is now the leading cause of death from infectious disease worldwide. This reflects the ability of its causative agent to persist, leading to failure of antibiotic treatment and development of drug resistance. In this project, we propose to overcome this by inhibiting a unique metabolic pathway that is activated when the pathogen enters its persistent state. We will use a cutting-edge combination of techniques to develop this pathway for next-generation therapies.
Investigation of a Novel Protein Implicated in Phosphate Metabolism in Bacteria. Phosphate is an important nutrient for all forms of life on Earth. A novel bacterial protein has been identified that appears to be important for the uptake or processing of phosphate, since mutants lacking the protein grow poorly inside certain cells of the human immune system (where phosphate levels are low) and in media containing low phosphate. The aims of this project are: to determine the role of the protein b ....Investigation of a Novel Protein Implicated in Phosphate Metabolism in Bacteria. Phosphate is an important nutrient for all forms of life on Earth. A novel bacterial protein has been identified that appears to be important for the uptake or processing of phosphate, since mutants lacking the protein grow poorly inside certain cells of the human immune system (where phosphate levels are low) and in media containing low phosphate. The aims of this project are: to determine the role of the protein by examining all phosphate containing molecules in our mutants; to determine its location in bacteria and functional domains; to identify other affected genes in our mutants; and, to find proteins that interact with this new protein. This project expects to demonstrate the importance of this protein in phosphate metabolism in bacteria.Read moreRead less
Structural And Functional Studies On Glutamate Decarboxylase.
Funder
National Health and Medical Research Council
Funding Amount
$500,460.00
Summary
This proposal aims to determine the molecular structure of the two known isoforms of Glutamate Decarboxylase (GAD65 and GAD67). GAD in an essential human enzyme that is responsible for synthesising the primary inhibitory neurotransmitter gamma-aminobutyric acid (GABA). GABA functions in the human Central Nervous System (CNS) to dampen down excitatory signals. Proper control of GABA synthesis is important and perturbations in GABA levels lies behind human diseases such as intractable epilepsy, de ....This proposal aims to determine the molecular structure of the two known isoforms of Glutamate Decarboxylase (GAD65 and GAD67). GAD in an essential human enzyme that is responsible for synthesising the primary inhibitory neurotransmitter gamma-aminobutyric acid (GABA). GABA functions in the human Central Nervous System (CNS) to dampen down excitatory signals. Proper control of GABA synthesis is important and perturbations in GABA levels lies behind human diseases such as intractable epilepsy, depression and schizophrenia. As a result of this role, numerous common therapeutics (for example benzodiazepines) target proteins involved in the GABA neurotransmitter system. The goal of this proposal is to use the molecular structures of GAD to understand how to achieve fine control of GABA production. In addition to its role in the CNS, GAD is an important human autoantigen. Antibodies to one isoform of GAD, GAD65, are found in most patients with type I diabetes as well as certain patients with the movement disorder stiff person syndrome and related diseases of the CNS. It is suggested that the development of auto-antibodies may play a key role in the pathophysiology of these conditions. Despite sharing >80% sequence similarity with GAD65, autoantibodies to the other isoform of GAD, GAD67, are rarely found in patients with disease. The aim of this grant is to characterise the region of GAD that is targetted by autoantibodes. These data will allow us to understand why certain autoantibodes are able to inhibit GAD enzyme activity and why GAD65, but not GAD67 is recognised by autoantibodes.Read moreRead less
Augmenting the activity of glyoxalase-1 to increase dicarbonyl clearance . Reactive intermediates generated during our metabolism contribute to ageing. Glyoxalase-1 is a key defence enzyme against these toxic intermediates and therefore ageing itself. This project aims to investigate novel pathways how the expression and activity of glyoxalase-1 are regulated. This interdisciplinary project expects to generate new understanding by combining relevant cell and animal models, protein chemistry, epi ....Augmenting the activity of glyoxalase-1 to increase dicarbonyl clearance . Reactive intermediates generated during our metabolism contribute to ageing. Glyoxalase-1 is a key defence enzyme against these toxic intermediates and therefore ageing itself. This project aims to investigate novel pathways how the expression and activity of glyoxalase-1 are regulated. This interdisciplinary project expects to generate new understanding by combining relevant cell and animal models, protein chemistry, epigenetics and structural biology. It is expected that this work will improve understanding of this fundamental biological defence. This will allow us to identify the potential means to enhance the capacity of glyoxalase-1 to the future benefit of biological ageing.Read moreRead less
Linkage Infrastructure, Equipment And Facilities - Grant ID: LE0561041
Funder
Australian Research Council
Funding Amount
$347,358.00
Summary
A New Generation Biosensor and Fluorescence Facility for Proteomics. The complete DNA sequence (the genome) is now known for many organisms and advances are being made to identify the complement of messenger RNA (the transcriptome) and the resultant collection of proteins (the proteome). The genome is largely fixed while the transcriptome and proteome differ between cell types in an organism and constantly vary to adapt the cell to changing conditions. The mediators of these variations are prote ....A New Generation Biosensor and Fluorescence Facility for Proteomics. The complete DNA sequence (the genome) is now known for many organisms and advances are being made to identify the complement of messenger RNA (the transcriptome) and the resultant collection of proteins (the proteome). The genome is largely fixed while the transcriptome and proteome differ between cell types in an organism and constantly vary to adapt the cell to changing conditions. The mediators of these variations are proteins, interacting with each other and with signal molecules. The next frontier in molecular biology is to identify and quantify these protein interactions. Our two institutions have a very large cohort of biologists whose research on proteins would be greatly facilitated by the Biacore 3000 and the ISS K2.Read moreRead less
Cellular Responses to Adversity: Oxidative Stress and Protection Against Oxidative Damage. A deficiency in the protein haem oxygenase-1 causes severe biological consequences in animals and humans. These include decreased reproduction, retarded development, the inability of the body to handle iron, chronic inflammation and increased susceptibility to age-associated diseases. This study will determine how a deficiency of the protein alters cells at the level of genes, proteins and protein function ....Cellular Responses to Adversity: Oxidative Stress and Protection Against Oxidative Damage. A deficiency in the protein haem oxygenase-1 causes severe biological consequences in animals and humans. These include decreased reproduction, retarded development, the inability of the body to handle iron, chronic inflammation and increased susceptibility to age-associated diseases. This study will determine how a deficiency of the protein alters cells at the level of genes, proteins and protein functions. By doing so, the project will illuminate how haem oxygenase-1 alters cell functions in a beneficial way. This information will eventually assist in preventing the serious disorders associated with deficiency of haem oxygenase-1. It will also provide the basis for novel treatments to slow down age-associated diseases.Read moreRead less
Virtual Screening In Structure-Based Drug Design For Malaria
Funder
National Health and Medical Research Council
Funding Amount
$285,000.00
Summary
Malaria continues to be one of the most serious health problems in the world today with approximately 300 million people affected and 1.5 million recorded deaths per year. The most deadly and widespread parasite responsible for this disease is Plasmodium falciparum. Because of the parasite's increasing resistance to traditional medication, there is an urgent need to develop more effective treatments. Two approaches are feasible: vaccines and new drugs. Both will probably be necessary to combat t ....Malaria continues to be one of the most serious health problems in the world today with approximately 300 million people affected and 1.5 million recorded deaths per year. The most deadly and widespread parasite responsible for this disease is Plasmodium falciparum. Because of the parasite's increasing resistance to traditional medication, there is an urgent need to develop more effective treatments. Two approaches are feasible: vaccines and new drugs. Both will probably be necessary to combat the spread and consequences of malaria. We are approaching this problem by targeting an enzyme which is essential for the survival of the parasite. All protozoan parasites make their purine nucleotides (the building blocks of DNA and RNA) by purine base salvage. Unlike humans, they cannot make purines from simple precursor molecules. The key enzyme in the salvage pathway is hypoxanthine-guanine-xanthine phosphoribosyltransferase (HGXPRT). Our plan is to capitalize on knowledge of the precise structure of HGXPRT and the increased power of computers to determine which chemicals are able to bind tightly and specifically to the active site of the enzyme. We will then test the ability of these compounds to inhibit purified human and Plasmodium enzymes and their ability to inhibit the growth of the malarial parasite in red cells. Chemical synthesis will be used to improve the effectiveness of these compounds.Read moreRead less
Gene identification and functional characterization for metabolism-based herbicide resistance in Lolium rigidum. Evolution of multiple herbicide resistance is widespread in Lolium rigidum in Australia. This resistance is very often endowed by enhanced rates of herbicide metabolism (metabolic resistance) involving cytochrome P450. This project aims to identify, clone and characterise important herbicide-metabolising P450 and other genes from multiple herbicide-resistant L. rigidum biotypes, and d ....Gene identification and functional characterization for metabolism-based herbicide resistance in Lolium rigidum. Evolution of multiple herbicide resistance is widespread in Lolium rigidum in Australia. This resistance is very often endowed by enhanced rates of herbicide metabolism (metabolic resistance) involving cytochrome P450. This project aims to identify, clone and characterise important herbicide-metabolising P450 and other genes from multiple herbicide-resistant L. rigidum biotypes, and develop transcriptional and biochemical markers for metabolic resistance diagnosis. Herbicide-metabolising gene discovery, characterisation and marker development will greatly extend the currently limited knowledge and understanding of metabolic resistance and help achieve sustainable weed management.Read moreRead less