Mechanistic Studies of Dimethylsulfide Dehydrogenase: A Novel Bacterial Molybdoenzyme. The aim of this proposal is to use electrochemical, spectroscopic and molecular biological techniques to understand the mechanism of action of the enzyme dimethylsulfide dehydrogenase. This enzyme is representative of an major group of molybdenum-containing enzymes that have importance in microbial biotransformations. The project will provide fundamental information about a multi-redox centre protein that has ....Mechanistic Studies of Dimethylsulfide Dehydrogenase: A Novel Bacterial Molybdoenzyme. The aim of this proposal is to use electrochemical, spectroscopic and molecular biological techniques to understand the mechanism of action of the enzyme dimethylsulfide dehydrogenase. This enzyme is representative of an major group of molybdenum-containing enzymes that have importance in microbial biotransformations. The project will provide fundamental information about a multi-redox centre protein that has potential application in biosensors and biocatalysis.Read moreRead less
Structural studies of catalysis and electron transfer by copper proteins. We propose to determine the crystal structures of five copper-containing proteins. Three are amine oxidases, enzymes that protect a wide range of organisms against toxic cell products (amines). Novel chemical modifications and crystallographic techniques will be used to test hypotheses for the enzyme mechanism. The results will provide a basis for the future manipulation of the enzymes' activities. Our other targets, s ....Structural studies of catalysis and electron transfer by copper proteins. We propose to determine the crystal structures of five copper-containing proteins. Three are amine oxidases, enzymes that protect a wide range of organisms against toxic cell products (amines). Novel chemical modifications and crystallographic techniques will be used to test hypotheses for the enzyme mechanism. The results will provide a basis for the future manipulation of the enzymes' activities. Our other targets, sulfocyanin and auracyanin-A, perform essential electron-transfer functions in an archaeon and a photosynthetic bacterium, respectively. The determination of their molecular structures will answer exciting questions about electron transfer in primitive organisms, and about the evolution of copper proteins as biological electron-transfer agents.Read moreRead less
How is molecular information passed between generations? This project aims to determine the mechanisms responsible for the inheritance of acquired traits. Sometimes the environment can have effects on the phenotype of not only the exposed individual, but also their children and grandchildren. While it is clear that this can occur, what is not clear is the mechanism by which this happens and the frequency at which it happens. This project will combine use of the model organism Caenorhabditis eleg ....How is molecular information passed between generations? This project aims to determine the mechanisms responsible for the inheritance of acquired traits. Sometimes the environment can have effects on the phenotype of not only the exposed individual, but also their children and grandchildren. While it is clear that this can occur, what is not clear is the mechanism by which this happens and the frequency at which it happens. This project will combine use of the model organism Caenorhabditis elegans with biochemistry and structural biology to determine what the molecular mechanism is by which this "transgenerational epigenetic inheritance" occurs.Read moreRead less
Chemical synthesis of cancer-associated glycoproteins. Glycosylation of proteins is an extremely common event which plays an important role in a variety of biological processes. Aberrant glycosylation and over-production of glycoproteins is associated with numerous cancer types (including breast, prostate, ovarian and small lung) and are recognised as promising agents for disease diagnosis and vaccine development. A range of cancer-associated glycoproteins will be synthesised in this research p ....Chemical synthesis of cancer-associated glycoproteins. Glycosylation of proteins is an extremely common event which plays an important role in a variety of biological processes. Aberrant glycosylation and over-production of glycoproteins is associated with numerous cancer types (including breast, prostate, ovarian and small lung) and are recognised as promising agents for disease diagnosis and vaccine development. A range of cancer-associated glycoproteins will be synthesised in this research program using a number of novel chemical technologies. These glycoproteins will be used to develop cancer vaccines and diagnostics. Cancer is a severe burden on the Australian community and on the economy, therefore this research will be of significant benefit to Australia.Read moreRead less
Mechanistic studies on the oxidation of amino acids, peptides and proteins and its biological consequences. Exposure of amino acids and proteins to radicals, oxidants, UV light, and metal ions results in oxidation, with consequent alteration to protein structure and function. It has been shown that these reactions occur during food spoilage, exposure of plants to excess UV light, and in a number of human diseases (e.g. heart disease and cancer). Despite evidence for a key role for protein oxidat ....Mechanistic studies on the oxidation of amino acids, peptides and proteins and its biological consequences. Exposure of amino acids and proteins to radicals, oxidants, UV light, and metal ions results in oxidation, with consequent alteration to protein structure and function. It has been shown that these reactions occur during food spoilage, exposure of plants to excess UV light, and in a number of human diseases (e.g. heart disease and cancer). Despite evidence for a key role for protein oxidation in these events, the fundamental chemistry and biochemistry of protein oxidation is incompletely understood. This is addressed in this project. Knowledge of the mechanisms of these reactions is a vital pre-requisite to the rational design of preventative strategies that might enhance food quality, minimise UV damage and enhance human health.Read moreRead less
Metalloproteins and metalloenzymes. Most of the chemical reactions and physical movements in living systems are carried out by proteins. The information for producing proteins from amino acids is stored in the genes, but many biological processes depend on additional atoms or molecules ('cofactors') that are added to a protein after it is assembled. For example, more than 30% of all proteins contain metal atoms which are essential for their function. We are studying the structures of such meta ....Metalloproteins and metalloenzymes. Most of the chemical reactions and physical movements in living systems are carried out by proteins. The information for producing proteins from amino acids is stored in the genes, but many biological processes depend on additional atoms or molecules ('cofactors') that are added to a protein after it is assembled. For example, more than 30% of all proteins contain metal atoms which are essential for their function. We are studying the structures of such metalloproteins and metalloenzymes so that we can better understand their activities with long term aims of creating new molecules for biotechnology and/or drugs.Read moreRead less
Functional and structural diversity of the cathepsin L peptidase from the human blood fluke Schistosoma mansoni. Peptidases are enzymes that are important in many infectious and physiological disease states. For example, they are used by infectious pathogens to enter human tissues and survive inside their bodies. The same type of enzymes also contribute to tissue damage in many pathological processes in humans such as cancer, arithritis and osteoporosis. There is an urgent need to define their s ....Functional and structural diversity of the cathepsin L peptidase from the human blood fluke Schistosoma mansoni. Peptidases are enzymes that are important in many infectious and physiological disease states. For example, they are used by infectious pathogens to enter human tissues and survive inside their bodies. The same type of enzymes also contribute to tissue damage in many pathological processes in humans such as cancer, arithritis and osteoporosis. There is an urgent need to define their structure and properties so that we can employ rational approaches to develop new drugs that can combat these diseases and ailments. Read moreRead less
Allosteric regulation, molecular structure and function of transglutaminase 2. With Australia's ageing population, we can expect to see increasing prevalence of pathologies such as cancer, Alzheimer's disease, and cataracts. The ubiquitous enzyme transglutaminase 2 (TG2) has been implicated in all of these age-related diseases, as well as in chronic disorders such as coeliac disease and diabetes, and may contribute in a positive way to wound healing. Understanding how TG2 is activated and inac ....Allosteric regulation, molecular structure and function of transglutaminase 2. With Australia's ageing population, we can expect to see increasing prevalence of pathologies such as cancer, Alzheimer's disease, and cataracts. The ubiquitous enzyme transglutaminase 2 (TG2) has been implicated in all of these age-related diseases, as well as in chronic disorders such as coeliac disease and diabetes, and may contribute in a positive way to wound healing. Understanding how TG2 is activated and inactivated, and how it selects its targets, will be a critical addition to current knowledge of this enzyme, and will be an essential prerequisite for the development of TG2-targetted drugs and other TG2-related therapies.Read moreRead less
Aminopeptidases involved in regulating the amino acid pool in malaria parasites. Aminopeptidases are pivotal to the normal functions of all cells. Abnormalities in their function and/or structure results in tissue damage in many pathological processes in humans such as cancer, neuronal diseases and hormonal action. They are also critical to viral, bacterial and parasitic infections as they are employed to remove amino acids from the host for use in building their own proteins. This project bring ....Aminopeptidases involved in regulating the amino acid pool in malaria parasites. Aminopeptidases are pivotal to the normal functions of all cells. Abnormalities in their function and/or structure results in tissue damage in many pathological processes in humans such as cancer, neuronal diseases and hormonal action. They are also critical to viral, bacterial and parasitic infections as they are employed to remove amino acids from the host for use in building their own proteins. This project brings national and international expertise together to define the structure and biological properties of these essential enzymes so that in the future we can employ rational approaches to develop new drugs that can combat these diseases and ailments.Read moreRead less
A Unique Target in the Purine Biosynthesis of the Pathogen Helicobacter pylori. The uptake systems of purine and analogues of the human pathogen Helicobacter pylori will be characterised because they can be utilised to introduce cytotoxic compounds into the cells. The first step in de novo purine biosynthesis of the bacterium is catalysed by two different enzymes, which are components of other biosynthetic pathways. These unique properties make them excellent potential therapeutic targets. Their ....A Unique Target in the Purine Biosynthesis of the Pathogen Helicobacter pylori. The uptake systems of purine and analogues of the human pathogen Helicobacter pylori will be characterised because they can be utilised to introduce cytotoxic compounds into the cells. The first step in de novo purine biosynthesis of the bacterium is catalysed by two different enzymes, which are components of other biosynthetic pathways. These unique properties make them excellent potential therapeutic targets. Their individual combined activities in purine biosynthesis will be characterised in situ and in vitro. Isogenic mutants with inactivated genes encoding for these enzymes will be constructed to investigate their role in the survival of the organism.Read moreRead less