"My research into biological systems brings together my expertise in spectroscopy and kinetics of proteins and small molecules and aims to understand the chemical basis of disease. Through studying how enzymes work at the molecular level we can understand how enzyme malfunction contributes to disease progression." - A/Prof Guy Jameson
Research
My research into enzyme mechanisms involves molecular biology and protein purification as well as physical, chemical and kinetic characterisation techniques. As my research is highly interdisciplinary, I collaborate with researchers from a variety of departments, including chemistry, biochemistry, anatomy, physiology and pathology. My research involves spectroscopic and kinetic investigations of biological systems and novel materials and my group studies materials ranging from coordination polymers, through to nanoparticles and small inorganic complexes, as well as biological samples such as proteins. In particular, we are interested in mechanistic studies of iron-containing heme and non-heme metalloenzymes.
Iron is the most abundant element on Earth and one of the most abundant in the Earth’s crust. Due to its high availability before the introduction of oxygen-producing organisms, it has been suggested that life started with iron (Günter Wächtershäuser). This also explains why iron-based chemistry lies at the heart of all life. Iron has a broad redox chemistry and therefore it is used in oxidation catalysis and bioenergetics, but is also used in acid-base reactions.
Our group wishes to understand how iron-oxygen reactivity is attained and regulated in the body and, through this develop knowledge that is essential for understanding both physiological and pathophysiological processes. This will increase knowledge of iron-oxygen reactivity in both chemistry and biology.
Standard molecular biology and protein purification techniques allow us to express and purify enzymes of interest. We use a range of fast-flow techniques, including stopped-flow, chemical quench and freeze-quench to investigate the rates of reactions and to isolate intermediates. Spectroscopic characterisation is though Mössbauer, EPR and NMR.
We also use Mössbauer spectroscopy to investigate a wide range of compounds from nanoparticles to coordination polymers and from proteins to whole cells. We run a low-temperature system in Bio21 and interested and happy to collaborate with anybody that might find this technique useful. Please contact guy.jameson@unimelb.edu.au(link sends e-mail) for more information.
Currently, we have two main research projects:
- Thiol dioxygenation. Thiol dioxygenases are a class of iron-containing enzymes that catalyse the oxidation of thiols to the corresponding sulfinates. These enzymes are found in practically all forms of life, including plants, bacteria, fungi and higher organisms. This work is carried out in collaboration with a number of people, in particular, structural work with Sigurd Wilbanks(link is external) at Otago University. To truly understand both the spectroscopic signatures and the underlying reasons for observed differences in reactivity at the atomic level, carrying out biochemical and small molecule model chemistry hand-in-hand provides both incredible strength and novelty. Small molecule models made by David Goldberg(link is external) at Johns Hopkins University provide invaluable information. Sam de Visser(link is external) at Manchester University calculates mechanisms and spectroscopic signals that we can compare with experiment.
- Peroxidases. Peroxidases use hydrogen peroxide to catalyse very important chemical transformations. Lactoperoxidase is a heme-containing enzyme that is part of the innate immune system and plays a key role in host defence by oxidising thiocyanate to the bactericidal agent hypothiocyanite. It is present in saliva, milk and other fluids. In particular, we are interested in understanding how lactoperoxidase reactivity can be regulated by physiologically relevant small molecules. This work is in collaboration with Tony Kettle(link is external) at Otago University, Christchurch. Peroxidase activity of cytochrome c is studied with Liz Ledgerwood(link is external) of Otago University.
Techniques
Guy Jameson is an expert in Mössbauer spectroscopy and has established, through the MacDiarmid(link is external) Institute, the first low-temperature Mössbauer laboratory in New Zealand. This capability is crucial for the study of iron-containing biological systems and vital when characterising the properties of magnetic materials.
- Spectroscopic techniques include Mössbauer and EPR and kinetic studies involving stopped-flow, chemical and freeze-quench.
- Standard molecular biology techniques to express and purify proteins of interest and study them using a variety of spectroscopic and kinetic techniques
Group Members
Group Leader
Guy Jameson
PhD Students
Joshua Prendergast
Zahra Shirani Sarmazeh
Biography
Dr Guy Jameson is an Associate Professor in the Faculty of Science's School of Chemistry at the University of Melbourne. His research area is spectroscopic and kinetic investigations of biological systems and novel materials. He studies materials ranging from coordination polymers, through nanoparticles to small inorganic complexes as well as biological samples such as proteins.
Guy was born and grew up in Dundee, Scotland. He received his undergraduate degree from University College, Oxford during which he worked on his Part II with Prof. Fraser Armstrong on the proton-coupled electron transfer to iron-sulfur cluster containing proteins. His doctoral work was carried out on catecholamine chemistry at the Technical University of Vienna under Prof. Wolfgang Linert. A postdoc with Prof. Vincent Huynh in the Physics Department at Emory University involved Mossbauer and EPR studies of a range of different iron-containing metalloproteins. His independent career started in 2006 at the University of Otago, New Zealand. He rose through the ranks of Lecturer, Senior Lecturer and Associate Professor during which time he was awarded the Hill-Tinsley Research Medal by the New Zealand Association of Scientists and elected Fellow of the New Zealand Institute of Chemistry. He moved to the School of Chemistry at the University of Melbourne in 2017.
Please follow for Guy Jameson's publications.(link is external)
Please follow the link to Guy Jameson's Faculty of Science group page.