Drugs are broken down in the body by the process of metabolism. Metabolism is important as both a detoxification and elimination mechanism, and determines dose rate for chronically administered drugs. Many drugs are metabolised by a reaction called glucuronidation. We will characterise the various components of the glucuronidation reaction in an integrated manner in order to understand and predict factors that influence an individual's capacity to metabolise drugs and other chemicals.
The Development Of Selective And Potent Kv1.3 Ion Channel Blockers For The Treatment Of Multiple Sclerosis
Funder
National Health and Medical Research Council
Funding Amount
$233,187.00
Summary
Building on the well-established path of developing drugs from Nature, the amplification of some unusual qualities of a naturally-occurring substance, khellinone, could lead to new treatments for autoimmune diseases such as multiple sclerosis and diabetes. Designed variants of khellinone are known to be very effective at preventing the destructive impact of the body's own T cells on the central nervous system that occurs in autoimmune disease.
Theoretical Investigations Into Permeation Dynamics In Calcium- And Potassium-Selective Membrane Ion Channels
Funder
National Health and Medical Research Council
Funding Amount
$517,243.00
Summary
All electrical activities in the brain are regulated by opening and closing of ion channels. Thus, understanding their mechanisms at a molecular level is a fundamental problem in biology. There are many different types of ion channels, each type fulfilling a different role. We now know the exact atomic structures of several types of the proteins forming ion channels. Using this newly unveiled information, we propose to build exact physical models of two important classes of ion channels, namely, ....All electrical activities in the brain are regulated by opening and closing of ion channels. Thus, understanding their mechanisms at a molecular level is a fundamental problem in biology. There are many different types of ion channels, each type fulfilling a different role. We now know the exact atomic structures of several types of the proteins forming ion channels. Using this newly unveiled information, we propose to build exact physical models of two important classes of ion channels, namely, the calcium channels and potassium channels, using the technique known as 'homology' modelling. Then, making use of powerful supercomputers and the special computer programs we have devised, we propose to follow the motion of ions as they move through the channel and study how some chemical compounds or drugs interfere with the normal functioning of the channel. Specifically, we will attempt to understand how verapamil, which is used to treat irregular heart beats and high blood pressure, interact with the calcium channel. Once we fully understand how these channels work, we will be able to understand the causes of, and possibly find the cures for, many neurological and muscular disorders, such as cardiac arhythmia and hypertension.Read moreRead less
Predicting Drug-drug Interactions Due To Tyrosine Kinase Inhibitors: Inhibition Of Drug Metabolising Enzymes And Transporters
Funder
National Health and Medical Research Council
Funding Amount
$535,495.00
Summary
Tyrosine kinase inhibitors (TKIs) are a new class of anticancer agents. Cancer patients typically receive multiple drugs, for the treatment of cancer and other diseases, increasing the probability of interactions between coadministered drugs. Despite the widespread use of TKIs, their potential to cause drug interactions is poorly understood. Using novel in vitro approaches, this project will identify drug interactions precipitated by TKIs thereby improving drug efficacy and patient safety.
Quantitative In Vitro-in Vivo Extrapolation: Realising The Promise
Funder
National Health and Medical Research Council
Funding Amount
$529,509.00
Summary
Most drugs are 'broken down', or metabolised, in the body by enzymes which are located mainly in liver. Knowing the efficiency of drug metabolism in patients is important for the discovery of new drugs and for the rational use of established drugs. This project will develop in vitro, or test-tube, approaches that predict how well a drug is metabolised in humans and whether it will interact with coadminsitered drugs. In turn, this allows prediction of drug dosage and frequency of administration.
Interaction Of New Kinase Inhibitor Drugs With Multi-drug Resistance (MDR) Transporter Proteins.
Funder
National Health and Medical Research Council
Funding Amount
$411,000.00
Summary
Multidrug transporter proteins are remarkable molecular pumps that expel a wide variety of drugs and toxins from cells. They are located at strategic sites where they eliminate harmful substances from the body or prevent them being absorbed from our diet in the first place. Multidrug transporters are also found at natural barriers within the body where they protect vulnerable tissue compartments, including the brain, cerebrospinal fluid, testes and, in preganant women, the foetus. Nevertheless, ....Multidrug transporter proteins are remarkable molecular pumps that expel a wide variety of drugs and toxins from cells. They are located at strategic sites where they eliminate harmful substances from the body or prevent them being absorbed from our diet in the first place. Multidrug transporters are also found at natural barriers within the body where they protect vulnerable tissue compartments, including the brain, cerebrospinal fluid, testes and, in preganant women, the foetus. Nevertheless, multidrug transporters sometimes interfere with drug therapy. They can prevent efficient absorption of drugs, increase the rate of drug elimination from the body, or prevent drug access to some tissues . Moreover, the activity of the transporters is quite variable, both between patients and within the same patient over time. This makes it difficult to provide optimal drug doses, particularly when treating cancer, where the drugs must be given at the maximum tolerated dose. The presence of drug transporter proteins in tumour cells can prevent entry of anticancer drugs, rendering them resistant to treatment. This is the main cause of failure in chemotherapy. This project will investigate a class of very promising new anticancer drugs, kinase inhibitors, to determine whether they are pumped by multidrug transporters, whether they alter the amounts of drug transporters in cells, and whether they alter transporter activity. We will also determine the consequences that follow from this for drug therapy. This information will help clinicians to rationally optimise therapy with the new drugs, to identify in advance both favourable (synergistic) and unfavourable (harmful) drug interactions in combination chemotherapy, to optimise drug doses and to minimise toxic side effects. The information will also add to our general understanding of drug absorption and elimination, and to the basic science of the remarkable multidrug transporter proteins.Read moreRead less
The Molecular Basis Of Cytochrome P450 Ligand Binding: Towards Predicting Enzyme Substrate Selectivity And Drug-drug Interaction Potential
Funder
National Health and Medical Research Council
Funding Amount
$558,447.00
Summary
Cytochrome P450 (CYP) enzymes play a pivotal role in the metabolism (i.e. chemical breakdown) of drugs, a process that is essential for their detoxification and elimination from the body. This project will combine advanced computational and experimental approaches to elucidate the molecular basis for the binding of drugs to CYP enzymes, which is crucial for the design of drugs with favourable metabolic properties and decreased propensity for harmful interactions with co-administered drugs.
Novel Fluorescent Probes Of Cellular Microenvironments To Study The Mechanism Of Action Of Endoperoxide Antimalarials
Funder
National Health and Medical Research Council
Funding Amount
$983,305.00
Summary
Malaria is responsible for the deaths of about two million children each year. As current drugs become increasingly useless due to the development of parasite resistance, there is an urgent need for new antimalarials. Artemisinin, an ancient Chinese drug that is extracted from wormwood, is now a front-line antimalarial, however its mechanism of action is not clear. Information about how artemisinin works is needed to help design cheap synthetic drugs that work in the same way.
State-dependence Of Drug Binding To HERG K+ Channels.
Funder
National Health and Medical Research Council
Funding Amount
$397,224.00
Summary
In recent years, it has become apparent that a wide range of prescription drugs can cause inadvertent inhibition of a potassium channel in the heart known as hERG, resulting in an increased risk of cardiac arrhythmias and death. This has prompted the withdrawal from the market of 9 drugs and the introduction of mandatory testing of all drugs for inhibition of hERG channels. In this proposal we seek a molecular explanation for the promiscuity of drug binding to hERG channels