Ronald Clarke

Ronald Clarke is Professor of Biophysical Chemistry in the School of Chemistry within the Faculty of Science at the University of Sydney. He obtained his BSc (Hons I) in 1981 and PhD in 1986 from the University of Adelaide, conducting his doctoral research under Dr. John Coates on the kinetics and mechanisms of cyclodextrin inclusion complexes. This work led to the discovery of a novel 2:1 guest:host complex between γ-cyclodextrin and methyl orange, along with a mathematical model describing the biphasic concentration dependence of relaxation times. Following his PhD, Clarke held postdoctoral positions in Germany, commencing with an Alexander von Humboldt Fellowship at the University of Konstanz (1987-1989) under Prof. Peter Läuger, where he investigated voltage-sensitive dyes and the Na+,K+-ATPase. He subsequently worked at the Fritz-Haber-Institut in Berlin (1990-1995) under Josef Holzwarth and at the Max-Planck-Institut für Biophysik in Frankfurt (1995-1999) under Ernst Bamberg, pioneering stopped-flow fluorimetry techniques to resolve the kinetics of the Na+,K+-ATPase ion pumping cycle using RH421 dye and developing spectroscopic methods for membrane dipole potential measurement.

In 1999, Clarke joined the University of Sydney as Lecturer in Physical and Theoretical Chemistry, progressing to Senior Lecturer (2003-2012) and Associate Professor (2013-present). His research centers on the biophysical chemistry of membrane transport proteins, with a focus on P-type ATPases including Na+,K+-ATPase (cell volume control), H+,K+-ATPase (stomach acid production), and sarcoplasmic reticulum Ca2+-ATPase (muscle relaxation). He investigates lipid modulation of enzyme activity, electrostatic regulation by intrinsically disordered N-termini, and drug-membrane interactions using the SURFE²R platform, the only one in the Southern Hemisphere. Key publications encompass 'Cholesterol depletion inhibits Na+,K+-ATPase activity in a near-native membrane environment' (2019), 'Order-disorder transitions of cytoplasmic N-termini in the mechanisms of P-type ATPases' (2020), and a 2023 review on autoinhibitory regulation via electrostatic stabilization. With over 5,200 citations, his contributions have advanced insights into ion transport mechanisms and disease origins. Clarke served as Treasurer of the Australian Society for Biophysics (2013-2019), joined the Biophysical Reviews editorial board (2022), and has been Secretary-General of the International Union of Pure and Applied Biophysics (IUPAB) since 2022.

Professional Email: ronald.clarke@sydney.edu.au