RECOMBINANT MALARIAL PYRIMIDINE ENZYMES AS DRUG TARGETS
Funder
National Health and Medical Research Council
Funding Amount
$229,750.00
Summary
Malarial parasites have now developed resistance to most of the available drugs and there is an urgent need for drugs with new mechanisms of action. Institutions collaborating on the Malarial Genome Project have sequenced the majority of DNA in the 14 chromosomes. The nucleotide sequence available on the internet contains thousands of open reading frames (ORFs) which encode proteins essential for survival of the parasite. Many of these proteins are enzymes which are suitable targets for drug dev ....Malarial parasites have now developed resistance to most of the available drugs and there is an urgent need for drugs with new mechanisms of action. Institutions collaborating on the Malarial Genome Project have sequenced the majority of DNA in the 14 chromosomes. The nucleotide sequence available on the internet contains thousands of open reading frames (ORFs) which encode proteins essential for survival of the parasite. Many of these proteins are enzymes which are suitable targets for drug development. A knowledge of the molecular architecture of the active site of such enzymes provides a template for drug design. The malarial parasite, Plasmodium falciparum, can only synthesise pyrimidine nucleotides for DNA via the de novo pyrimidine pathway. We have cloned the genes encoding three of the enzymes of the de novo pathway using sequence information from the Malarial Genome Project. Dihydroorotase, orotate phosphoribosyltransferase, and OMP decarboxylase, catalyse reactions 3, 5 and 6 of the pathway. We have expressed these enzymes in the bacterium Escherichia coli enabling large-scale production of these drug targets. We propose to characterise the catalytic and inhibitory properties of these enzymes, and grow protein crystals for determination of atomic structures by x-ray diffraction. The structures will provide templates for rational design of new antimalarial drugs. In a second approach for develoment of new drugs, the 3 malarial enzymes will be screened against chemical libraries for inhibition of catalytic activity. The initial screen will utilise a high throughput Biacore 3000 instrument which detects strong interactions between a target enzyme and candidate inhibitors. A thorough knowledge of the catalytic mechanisms, the three-dimensional structures and novel first generation inhibitors of these 3 malarial target enzymes, will provide a strong basis for development of new antimalarial drugs.Read moreRead less
STRUCTURAL STUDIES OF KEY REGULATORY PROTEINS OF THE COMPLEMENT CASCADE
Funder
National Health and Medical Research Council
Funding Amount
$437,545.00
Summary
This work is expected to lead to the determination of the three-dimensional shape of important immune regulatory proteins using X-ray crystallography. In this method, protein crystals are grown and their atomic structure determined by placing them in a beam of X-rays. The crystals cause the X-rays to scatter in a pattern which is characteristic of the protein's three-dimensional shape. Knowledge gained from the proteins' shape provides important insights into their biological function and form t ....This work is expected to lead to the determination of the three-dimensional shape of important immune regulatory proteins using X-ray crystallography. In this method, protein crystals are grown and their atomic structure determined by placing them in a beam of X-rays. The crystals cause the X-rays to scatter in a pattern which is characteristic of the protein's three-dimensional shape. Knowledge gained from the proteins' shape provides important insights into their biological function and form the basis for the rational design of new drugs to combat diseases. In particular, we are interested in determining the 3-D shapes of important proteins that control immunity. Sometimes these proteins can function abnormally resulting in serious diseases such as autoimmune diseases, stroke, Alzheimer's disease, heart attack, haemorrhagic shock, sepsis, adult respiratory distress syndrome, asthma and organ transpant rejection. Thus the ability to provide new drugs has important clinical ramifications in the treatment of these diseases.Read moreRead less
Alzheimer's disease is the most common form of dementia and is the fourth biggest killer in developed countries. This proposal concerns the biochemical investigation of a protein implicated in Alzheimer's disease. This work is expected to lead to the determination of the three-dimensional shape of the protein which will provide an understanding of what the protein's normal function is in the body and may form the basis for the design of drugs to combat the disease.
A Novel Mode Of Cytokine Receptor Assembly And Activation: Functional And Structural Characterization
Funder
National Health and Medical Research Council
Funding Amount
$621,322.00
Summary
This proposal will study a group of protein hormones and their receptors, implicated in blood cell cancers and inflammatory diseases and for which current treatments are inadequate. We will determine the mechanism of receptor activation and in particular will seek to link different forms of receptor assembly to different functions. This information will help us develop new drugs with more specificity for certain hormone functions and thus less side effects
An X-ray Crystallographic Investigation Into The Structural Basis Of T-cell Allorecognition
Funder
National Health and Medical Research Council
Funding Amount
$441,000.00
Summary
X-ray crystallography is an essential tool for solving the three-dimensional (3-D) structure of proteins. Proteins control the biological processes within the cell and it is the exact shape of proteins that determines how they function. Each protein is made up like a string of beads, with the building units being amino acids. Depending on the sequence of the amino acids, the protein molecule bends and forms a distinct, complex shape. This three dimensional shape allows it to specifically interac ....X-ray crystallography is an essential tool for solving the three-dimensional (3-D) structure of proteins. Proteins control the biological processes within the cell and it is the exact shape of proteins that determines how they function. Each protein is made up like a string of beads, with the building units being amino acids. Depending on the sequence of the amino acids, the protein molecule bends and forms a distinct, complex shape. This three dimensional shape allows it to specifically interact with carbohydrates, other proteins, such as enzymes or receptors, or even with molecules like DNA, to have its effect. To determine how a protein acts, it is vital to know the precise three-dimensional shape of a protein at the atomic level. This work is focused on understanding the precise shape of proteins that control the immune system. The immune system is avital process whereby individuals can fight off disease. This work will further our understanding of the immune system.Read moreRead less
The general aim of this work is to investigate the three-dimensional structures of important target proteins using X-ray crystallography. Protein crystallography is the study of the three-dimensional shapes of proteins at near atomic resolution. In this method proteins are made to form crystals. X-ray beams are then shone on the crystals causing the X-rays to scatter in a pattern which is characteristic of the protein's three-dimensional shape. Knowledge of the structure of proteins is necessary ....The general aim of this work is to investigate the three-dimensional structures of important target proteins using X-ray crystallography. Protein crystallography is the study of the three-dimensional shapes of proteins at near atomic resolution. In this method proteins are made to form crystals. X-ray beams are then shone on the crystals causing the X-rays to scatter in a pattern which is characteristic of the protein's three-dimensional shape. Knowledge of the structure of proteins is necessary for the complete understanding of their biological activity and is also very useful for the rational design of new drugs that may alter their activity. Approximately one third of the body's proteins are attached to membranes. However, relatively little is known about the three-dimensional structures of this important class of proteins. In this project the structures of proteins that form pores in membrane cell walls are being determined. Some of these proteins are bacterial toxins and knowledge of their structure may prove useful in the design of new antibiotics. Another project involves work on a protein called GABA. The structure of GABA could lead to new drugs that control epilepsy, act as general anaesthetics, relieve anxiety and induce sleep.Read moreRead less
This proposal concerns the biochemical investigation of a protein called GABA receptor which is a known target for various anti-anxiety drugs (anxiolytics), anti-convulsants, sedatives, depressants, anti-epilespy drugs, alcohol and anaesthetics. This work is expected to lead to the determination of the three-dimensional shape of the protein which will provide essential information about how the protein works and lay the foundation for the design and development of new drugs to control epilepsy, ....This proposal concerns the biochemical investigation of a protein called GABA receptor which is a known target for various anti-anxiety drugs (anxiolytics), anti-convulsants, sedatives, depressants, anti-epilespy drugs, alcohol and anaesthetics. This work is expected to lead to the determination of the three-dimensional shape of the protein which will provide essential information about how the protein works and lay the foundation for the design and development of new drugs to control epilepsy, act as general anaesthetics, relieve anxiety and induce sleep.Read moreRead less