Role of 3'-phosphorylated phosphoinositides in neurosecretion. Neurons communicate through the release of neurotransmitter by synaptic vesicles. Minute changes underlie normal processes such as memory and modifications of neurotransmitter level contribute to a number of neurological diseases. I am interested in deciphering the role of phosphoinositides, an inner membrane-based lipid, during steps leading to the fusion of a synaptic vesicle with the plasma membrane. I have recently discovered tha ....Role of 3'-phosphorylated phosphoinositides in neurosecretion. Neurons communicate through the release of neurotransmitter by synaptic vesicles. Minute changes underlie normal processes such as memory and modifications of neurotransmitter level contribute to a number of neurological diseases. I am interested in deciphering the role of phosphoinositides, an inner membrane-based lipid, during steps leading to the fusion of a synaptic vesicle with the plasma membrane. I have recently discovered that phosphatidylinositol-3 phosphate production was critical for the vesicle to acquire the competence to fuse with the plasma membrane. This project aim to understand by which mechanism this lipid interacts with the release machinery to promote such priming step.Read moreRead less
Structural and Functional Aspects of the Allosteric Regulation of Pyruvate Carboxylase by Acyl-CoA Compounds. Pyruvate carboxylase occupies a central location in intermediary metabolism catalysing the formation of oxaloacetate, a key component of the Krebs' tricarboxylic acid cycle especially in its synthetic modes in gluconeogenesis, lipogenesis and in the synthesis of neurotransmitters.
This project aims: (i) To produce crystals of pyruvate carboxylase for determining its structure by X-ra ....Structural and Functional Aspects of the Allosteric Regulation of Pyruvate Carboxylase by Acyl-CoA Compounds. Pyruvate carboxylase occupies a central location in intermediary metabolism catalysing the formation of oxaloacetate, a key component of the Krebs' tricarboxylic acid cycle especially in its synthetic modes in gluconeogenesis, lipogenesis and in the synthesis of neurotransmitters.
This project aims: (i) To produce crystals of pyruvate carboxylase for determining its structure by X-ray diffraction; (ii) To use affinity-labelling to determine the amino acid residues in the binding site of the enzyme's allosteric activator, acetyl-CoA; (iii) To construct chimeric enzymes from different species to define regions of the enzyme which affect its responses to its important allosteric activator, acetyl-CoA.
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Studies on the stereospecific interaction between aldose reductase and inhibitor. There is no therapy specific for treatment of diabetes complications accepted worldwide. The enzyme aldose reductase has shown promising results as a drug target for preventing or delaying the onset of the complications. The structures of human aldose reductase holoenzyme in complex with stereoisomers of the potent inhibitor Fidarestat will be determined at high resolution in order to elucidate the binding modes re ....Studies on the stereospecific interaction between aldose reductase and inhibitor. There is no therapy specific for treatment of diabetes complications accepted worldwide. The enzyme aldose reductase has shown promising results as a drug target for preventing or delaying the onset of the complications. The structures of human aldose reductase holoenzyme in complex with stereoisomers of the potent inhibitor Fidarestat will be determined at high resolution in order to elucidate the binding modes responsible for the differences in their inhibitory potencies. The results may lead to the design of better inhibitors of the enzyme for the treatment of diabetes sufferers, at least until better methods for maintaining metabolic control are developed.Read moreRead less
Structure-based discovery of dipeptidyl peptidase IV inhibitors. Diabetes afflicts approximately 151 million people worldwide, with an estimated increase to 221 million by 2010. To date, no therapy for the treatment of diabetes complications is widely accepted. The enzyme dipeptidyl peptidase IV has shown promising results as a target for the treatment of type 2 diabetes. Structural studies of dipeptidyl peptidase IV in complex with inhibitor will be conducted to elucidate the details of the e ....Structure-based discovery of dipeptidyl peptidase IV inhibitors. Diabetes afflicts approximately 151 million people worldwide, with an estimated increase to 221 million by 2010. To date, no therapy for the treatment of diabetes complications is widely accepted. The enzyme dipeptidyl peptidase IV has shown promising results as a target for the treatment of type 2 diabetes. Structural studies of dipeptidyl peptidase IV in complex with inhibitor will be conducted to elucidate the details of the enzyme-inhibitor interaction. The results will be used to identify the molecular basis of potency and selectivity of dipeptidyl peptidase IV inhibitors and may lead to the discovery of pharmaceutical agents for the treatment of diabetes sufferers.Read moreRead less
Crystallographic studies of aldose and aldehyde reductases. The ability of aldose reductase to reduce the excess glucose that results from the hyperglycaemia of diabetes has been linked to the development of diabetic complications. Recent studies link the lack of a clinically suitable aldose reductase inhibitor to lack of inhibitor selectivity. The structures of the complexes of aldose and aldehyde reductases with various inhibitors should allow us to establish the important aspects of the inh ....Crystallographic studies of aldose and aldehyde reductases. The ability of aldose reductase to reduce the excess glucose that results from the hyperglycaemia of diabetes has been linked to the development of diabetic complications. Recent studies link the lack of a clinically suitable aldose reductase inhibitor to lack of inhibitor selectivity. The structures of the complexes of aldose and aldehyde reductases with various inhibitors should allow us to establish the important aspects of the inhibitor interaction with the residues of the active site. This information will be used in the design of more specific aldose reductase inhibitors.Read moreRead less
New Insights into the Structure and Function of Pyruvate Carboxylase. Pyruvate carboxylase plays an essential roles in insulin secretion by pancreatic islets and in normal brain function, but excess expression of this enzyme in liver and adipose tissue is associated with diabetes and obesity.
Understanding the function of each structural feature in the reaction mechanism of an enzyme is essential to designing safe and effective pharmaceuticals that are required to modulate its activity.
Th ....New Insights into the Structure and Function of Pyruvate Carboxylase. Pyruvate carboxylase plays an essential roles in insulin secretion by pancreatic islets and in normal brain function, but excess expression of this enzyme in liver and adipose tissue is associated with diabetes and obesity.
Understanding the function of each structural feature in the reaction mechanism of an enzyme is essential to designing safe and effective pharmaceuticals that are required to modulate its activity.
This project, which will use cutting edge techniques in an experimental model, seeks to characterise this important enzyme's function so that better treatments can be developed in future for diabetes and obesity.
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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
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
Inhibiting pathological signalling in haematopoietic disease. Certain leukaemias and other blood diseases are caused by the mutation of one particular molecule, called Janus Kinase (JAK), inside our bodies. This project aims to understand the biochemical details of these diseases by studying this mutated molecule in detail. The project will aim to provide the information for developing effective therapeutics against these diseases.
This project aims to investigate novel ways to treat children with the inherited brain disorder known as MPS IIIA. This condition is currently untreatable and children generally die in their teens. We will use a mouse model of this condition to examine the effectiveness of combining two different treatment approaches, in order to maximise outcomes.