13:00 - 14:00
Mon 20 May, 2024

PLT

Prof Peter Lay joins us to deliver this departmental seminar. All staff and students welcome. Refreshments will be served outside PLT at 12:45

Abstract

There is considerable debate as to whether vanadium is an essential trace element for humans. Recently, there is mounting evidence that it may have an essential role in glucose metabolism and other functions to maintain human health. Vanadium complexes have also been explored extensively for their potential as anti-diabetic and anti-cancer drugs. In addition, there is considerable controversy as to appropriate criteria to identify ancient microfossils from carbonaceous deposits that are similar in appearance to genuine microfossils. We have identified the use of vanadium as a biomarker to make this distinction.

Information obtained from X-ray fluorescence microscopy, X-ray absorption spectroscopy and synchrotron radiation FTIR microscopy and various biochemical assays will be discussed with respect to understanding V biochemistry. In particular, XAS has been used to identify speciation that occurs within biological fluids and treated and untreated cells, which is important in understanding their modes of action. For instance, many V drugs undergo decomposition in cell medium and the released ligands are important in the in-vitro activities of many V anti-cancer drugs. Similar time-dependent intracellular vanadium speciation occurs for most V anti-diabetic and anti-cancer cells, with the main role of the ligands to deliver V either into the cell, or to biomolecules such as transferrin and serum albumin that interact with the cell. With respect to diabetes, XFM combined with micro-XANES has been used to determine the distribution of V in both treated and untreated adipocytes (fat cells). The results indicate such cells naturally accumulate V and together with other results on glucose metabolism, cell signalling, etc., V may have an essential role. XFM was also used to determine that vanadium could be detected in genuine microfossils in the cytosolic space and is an important biomarker of such fossils and potentially useful as biomarkers for fossilized extracellular life in carbonaceous material.

Biography

Prof. Peter A. Lay completed his BSc(Hon1) from the University of Melbourne in 1977 and received his PhD from the Australian National University in 1981. He was a CSIRO Postdoctoral Fellow (1981–1984) at Stanford University and CSIRO, and a QEII Fellow (1984–1985) at Deakin University. He was appointed as a Lecturer in Inorganic Chemistry (1985) at the University of Sydney and became a full Professor in 1997 and was twice awarded Australian Research Council Professorial Fellows. He is currently an Emeritus Professor of Chemistry at the University of Sydney and a Fellow of the Australian Academy of Science (AAS) and the Royal Society of New South Wales. He was awarded the David Craig Medal (Chemistry) of the AAS and a Lifetime Achievement Award for Synchrotron Science (AS) by ANSTO (the operators of the Australian Synchrotron. He was Chair of the Committee for the design and construction of the new MEX (medium-energy XAS) beamlines at the (AS) and has contributed to committees and symposia on the conceptual design and construction of new XAS and XFM beamlines at the CLS, APS and SSRL. His research is in bio-inorganic chemistry, inorganic medicinal chemistry and biomedical applications of vibrational spectroscopy and synchrotron science.