Synthesis of substrate analogues for probing catalytic mechanisms and specificity of enzymes involved in the metabolism of plant polysaccharides. The project is aimed at strengthening collaborations between research groups in Adelaide and France, with the specific objective of synthesizing substrate analogues as probes of enzymatic mechanisms and substrate specificity in polysaccharide hydrolases and synthases of barley. The chemical expertise resides in France, while the enzymatic work will be ....Synthesis of substrate analogues for probing catalytic mechanisms and specificity of enzymes involved in the metabolism of plant polysaccharides. The project is aimed at strengthening collaborations between research groups in Adelaide and France, with the specific objective of synthesizing substrate analogues as probes of enzymatic mechanisms and substrate specificity in polysaccharide hydrolases and synthases of barley. The chemical expertise resides in France, while the enzymatic work will be conducted largely in Australia. Exchange of research staff, particularly at the postgraduate student and research associate levels, is considered essential to capture the benefits of the complementary expertise and to extend an existing international collaboration. The target enzymes are of central importance in cell wall metabolism during development of higher plants.Read moreRead less
Molecular mechanisms of catalysis and the basis of substrate specificity in polysaccharide hydrolases. Reaction intermediates along hydrolytic pathways and molecular determinants of substrate specificity of barley B-glucan exo- and endohydrolases will be defined using crystallographic and kinetic analyses. These enzymes are of central importance in cell wall metabolism during development of higher plants, and in plant-pathogen interactions. Realization of the project objectives will not only pro ....Molecular mechanisms of catalysis and the basis of substrate specificity in polysaccharide hydrolases. Reaction intermediates along hydrolytic pathways and molecular determinants of substrate specificity of barley B-glucan exo- and endohydrolases will be defined using crystallographic and kinetic analyses. These enzymes are of central importance in cell wall metabolism during development of higher plants, and in plant-pathogen interactions. Realization of the project objectives will not only provide fundamental information on catalytic mechanisms, but will also provide opportunities to manipulate enzyme specificity. Further, site-directed mutagenesis of the enzymes will be used to generate glycosynthases, which will be evaluated for their ability to synthesise novel oligosaccharide and polysaccharide products, some of which might show immunomodulating activity.Read moreRead less
Characterisation of the oxygen-sensing asparaginyl hydroxylase, FIH-1, and hydroxylase-specific antagonists. This research will provide fundamental information on how cells and whole organisms can sense and respond accordingly to oxygen deficiency. This information is fundamental for our understanding of embryo development and adult life in different environments, and central to the diagnosis and treatment of diseases such as stroke, cardiovascular disease, and cancer. This research will contrib ....Characterisation of the oxygen-sensing asparaginyl hydroxylase, FIH-1, and hydroxylase-specific antagonists. This research will provide fundamental information on how cells and whole organisms can sense and respond accordingly to oxygen deficiency. This information is fundamental for our understanding of embryo development and adult life in different environments, and central to the diagnosis and treatment of diseases such as stroke, cardiovascular disease, and cancer. This research will contribute to our basic knowledge of these processes, provide invaluable information about the specific genes and proteins involved, and provide direct information about the therapeutic potential of specific drugs or inhibitors designed to target this oxygen response in human disease.Read moreRead less
Polysaccharide Synthase Genes in Agro-Industrial Applications. Achievement of the project aims will generate valuable intellectual property and meet National Research Priorities by: enhancing our knowledge base for the production of renewable bio-fuels from crop residues, for an environmentally sustainable Australia; developing preventative healthcare through adoption of healthier diets, rich in non-starchy cell wall polysaccharides that help reduce the incidence and severity of cardiovascular d ....Polysaccharide Synthase Genes in Agro-Industrial Applications. Achievement of the project aims will generate valuable intellectual property and meet National Research Priorities by: enhancing our knowledge base for the production of renewable bio-fuels from crop residues, for an environmentally sustainable Australia; developing preventative healthcare through adoption of healthier diets, rich in non-starchy cell wall polysaccharides that help reduce the incidence and severity of cardiovascular disease, obesity, diabetes and some cancers; and by developing breakthrough science in emerging agricultural technologies. The alliance will foster an intellectual environment to provide world-class basic research outcomes and training of highly skilled graduates, thereby contributing to the 'knowledge nation'.Read moreRead less
Novel regulation of TRP channels by oxygen-dependent hydroxylation. Factor inhibiting HIF-1 (FIH-1) is an oxygen-sensing asparaginyl hydroxylase. A bioinformatic search identified specific transient receptor potential (TRP) ion channels as likely substrates. The hypothesis is that TRP channels are regulated by hypoxia, mediated through a novel mechanism of oxygen-dependent hydroxylation by FIH. The aim of this project is to investigate how hydroxylation by FIH mediates the hypoxic regulation of ....Novel regulation of TRP channels by oxygen-dependent hydroxylation. Factor inhibiting HIF-1 (FIH-1) is an oxygen-sensing asparaginyl hydroxylase. A bioinformatic search identified specific transient receptor potential (TRP) ion channels as likely substrates. The hypothesis is that TRP channels are regulated by hypoxia, mediated through a novel mechanism of oxygen-dependent hydroxylation by FIH. The aim of this project is to investigate how hydroxylation by FIH mediates the hypoxic regulation of TRP channels. Preliminary data show that the first candidate, TRPV3, is activated in hypoxia, is hydroxylated by FIH, and hydroxylation mediates changes in activity. Ion channels are important for the physiological response to hypoxia, and this project aims to define a novel mechanism for this response, with relevance to mammalian physiology.Read moreRead less
Characterisation of vital carbohydrate synthases in pathogenic oomycetes. This project aims to understand the mechanisms that control cell wall stability in the fish pathogen, Saprolegnia parasitica. The biochemical properties and function of vital enzymes involved in cell wall biosynthesis will be determined using innovative approaches at the interface of biochemistry, microbiology, cell biology, and structural biology. Next generation ion mobility mass spectrometry will be used to solve challe ....Characterisation of vital carbohydrate synthases in pathogenic oomycetes. This project aims to understand the mechanisms that control cell wall stability in the fish pathogen, Saprolegnia parasitica. The biochemical properties and function of vital enzymes involved in cell wall biosynthesis will be determined using innovative approaches at the interface of biochemistry, microbiology, cell biology, and structural biology. Next generation ion mobility mass spectrometry will be used to solve challenging structural questions that cannot be tackled with conventional techniques. Expected outcomes include new knowledge on challenging membrane proteins that allows development of novel strategies for disease control in aquaculture. The data may also be applicable to crop protection from related plant pathogens.Read moreRead less
Three-dimensional structures, substrate specificities and catalytic mechanisms of polysaccharide synthases. Plant wall polysaccharides are extensively used for food and fibre, and are important dietary components in human nutrition. A precise knowledge of mechanisms used by plants to synthesize these polysaccharides is unavailable, but would reveal potential routes to manipulate their biosynthesis in important crop species. For example, the levels or structures of polysaccharides might be modif ....Three-dimensional structures, substrate specificities and catalytic mechanisms of polysaccharide synthases. Plant wall polysaccharides are extensively used for food and fibre, and are important dietary components in human nutrition. A precise knowledge of mechanisms used by plants to synthesize these polysaccharides is unavailable, but would reveal potential routes to manipulate their biosynthesis in important crop species. For example, the levels or structures of polysaccharides might be modified to improve their efficacy as anti-cancer agents in human diets, to enhance digestibility of animal stock feeds, or to synthesise pharmologically valuable compounds. Thus, economic, social and environmental benefits will flow to both producers and consumers. 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.
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.
Read moreRead less