Associate Professor Ronald Clarke

BSc PhD Adelaide
Associate Professor

F11 - Chemistry Building
The University of Sydney

Telephone 61 2 9351 4406
Fax 61 2 9351 3329

Website Contact Details

Biographical details

  • BSc (Hons I) 1981, PhD 1986, University of Adelaide
  • Humboldt Fellow, University of Constance, 1987-88
  • Leverhulme Fellow, University of East Anglia, 1989
  • Max Planck Research Fellow, Liebig Fellow, Fritz Haber Institute, Berlin, 1990-94
  • Dr. Habil. (Physical Chemistry), 1995, Free University of Berlin
  • Max Planck Research Fellow, Max Planck Institute for Biophysics, Frankfurt/Main 1995-99
  • Dr. Habil. (physical chemistry) 1999, Johann Wolfgang von Goethe University, Frankfurt/Main
  • University of Sydney; Lecturer 1999-2002
  • University of Sydney; Senior Lecturer 2003 - 2012
  • University of Sydney, Associate Professor 2013 -
  • Dozor Visiting Professor, Ben-Gurion University of the Negev, Beer-Sheva, Israel, 2008
  • McAulay-Hope Prize for Original Biophysics (Australian Society for Biophysics), 2010
  • Visiting Professor, University of Science and Technology Hanoi, Vietnam, 2011 -
  • Research Affiliate, Kolling Institute of Medical Research, Sydney
  • Humboldt Fellow, Technical University Berlin, 2014-2015

Research interests

  • Biophysical chemistry
  • Biological membranes and membrane proteins
  • Fluorescence spectroscopy
  • Rapid reaction kinetics
  • Regulation and mechanism of ion transport across biological membranes
  • Voltage-sensitive fluorescent dyes
  • Na+,K+-ATPase
  • Membrane electrical properties

Ion-transporting Membrane Proteins: Ion-transporting membrane proteins play a decisive role in the metabolism of all cells and in numerous physiological processes, e.g., ATP production, nerve impulse propagation, and muscle contraction. A deeper understanding of their mechanisms and regulation can be obtained by the determination of the kinetics of their individual reaction steps. One approach to this research goal is to make use of the electrical current they generate across the cell membrane and to apply electrophysiological methods, such as the patch-clamp technique. Another is to convert the electrical voltage that the proteins produce into an optical signal by incorporating a voltage-sensitive dye into the membrane. Voltage-sensitive styrylpyridinium dyes allow a rapid detection (within nanoseconds) of local changes in electrical field strength within membranes. The great advantage of the dyes is that they allow one to investigate electrogenic reaction steps of membrane proteins in open membrane fragments, i.e. conditions under which electrophysiological methods are not applicable.

Na+,K+-ATPase: The Na+,K+-ATPase is the enzyme responsible for maintaining the physiological essential Na+ and K+ concentration gradients across the plasma membrane of all animal cells. Jens-Christian Skou (University of Aarhus, Denmark) was awarded the Nobel Prize for Chemistry for its discovery in 1997. Using the voltage-sensitive probe RH421 in conjunction with the fluorescence stopped-flow method we have investigated in detail the enzyme’s kinetics and mechanism. This has allowed us to determine rate constants for most of the steps of the enzyme’s reaction cycle and to locate the rate-determining steps. The reaction cycle of the Na+,K+-ATPase is universally described in biology and chemistry textbooks by the Albers-Post model, which represents the catalytic unit of the enzyme as a monomer undergoing a sequence of ion-binding, conformational changes and ATP phosphorylation/dephosphorylation steps. Recently we have discovered that this description is inadequate and, based on our experimental results, have proposed a new model, in which the enzyme exists in dimeric form with two gears of ion pumping depending on the number of ATP molecules bound. We are currently investigating further the mechanism by which the two gears of pumping come about.

Membrane Dipole Potential and Orientational Polarisability: Ion-transporting membrane proteins, such as the Na+,K+-ATPase, are very sensitive to the composition of their lipid surroundings. The mechanisms by which lipids and membrane proteins interact are still unclear. One possibility which we are investigating is via an electrostatic interaction between charged or dipolar groups on both the lipid and the protein. Within the head-group region of phospholipid membranes there exists an electrical potential (the dipole potential) of ca. 200-400 mV, positive in the membrane interior. This produces a very large electric field strength of around 109 V m-1 within the membrane, which could potentially influence the energy of intermediate states in the pumping cycle of ion-transporting membrane proteins, thus changing the activation energies of steps of the cycle and hence their rate constants. However, another important consideration is the degree to which charged groups of the lipid are free to reorientate around the intermediate states of ion pumps, which is determined by the order or the fluidity of the membrane. The effects of the dipole potential and membrane fluidity are combined in the concept of the membrane orientational polarisability, for which we recently developed a fluorescence-based method of determination using the probe di-8-ANEPPS. Future work will involve analysing for a correlation between orientational polarisability and ion pump activity.

Fluorescent Styrylpyridinium Voltage-Sensitive Membrane Probes: Voltage-sensitive membrane probes based on the styrylpyridinium fluorophore have proven to be very useful in the neurosciences for the optical imaging of voltage transients of neurons and in biophysical research for the investigation of the kinetics of ion-transporting membrane proteins. However, in spite of the successes which have been achieved through their use, they suffer from the disadvantage that they are often photochemically unstable and phototoxic. In order to develop improved probes it is necessary to obtain fundamental knowledge on the origin of the dyes’ photochemistry. We have been investigating in particular the probe RH421, which displays the unusual property of undergoing an increase in its fluorescence on excitation when bound to lipid membranes, and the more recently developed probe ANNINE 5.

Selected grants

2014

  • University of Sydney Automated Peptide Synthesis Platform; Payne R, Britton W, Byrne S, Chan K, Clarke R, Hunt N, Jolliffe K, Kassiou M, Lay P, Mackay J, Matthews J, McErlean C, New E, Rasmussen H, Rendina L, Rudrawar S, Rutledge P, Shepherd N; National Health and Medical Research Council (NHMRC)/Equipment Grants.

2013

  • SF-61SX2/s stopped-flow fluorimeter and Service and upgrade of SX-17MV stopped-flow spectrometer; Clarke R, Davies M, Lay P, Witting P, Rasmussen H, Matthews J, Pattison D, Vandenberg J; National Health and Medical Research Council (NHMRC)/Equipment Grants.

2012

  • Electromechanical controls of membrane transport phenomena; Allen T, Clarke R; Australian Research Council (ARC)/Discovery Projects (DP).

2011

  • automated storage, retrieval, and UV imaging system; Jormakka M, Gamble J, Semsarian C, Rasko J, Vadas M, Xia P, Gorrell M, Clarke R, Holst J, Church W; National Health and Medical Research Council (NHMRC)/Equipment Grants.

2006

  • Regulation of the sarcolemmal Na-K pump by FXYD proteins associated with it; Rasmussen H, Marassi F, Clarke R; National Health and Medical Research Council (NHMRC)/Project Grants.

2005

  • In situ measurements of the electorstatic potential within redox proteins via a quinone-linked voltage-sensative fluorescent probe; Goldys E, Kable S, Clarke R; ARC/NHMRC Research Network for Fluorescence Applications in Biotechnology and Life Sciences (NHMRC)/FABLS Support Scheme for Emerging Research Projects.

2004

  • In situ measurements of the electrostatic properties inside photosynthetic reaction centres; Clarke R; Australian Research Council (ARC)/Linkage International: ARC International Fellowships (ARCIF).

2002

  • Function and regulation of the Na+,K+-ATPase; Clarke R, Else P, Cornelius B, Apell H; Australian Research Council (ARC)/Discovery Projects (DP).

2001

  • Mechanism of the rate-determining step of the Na+, K+-ATPhase; Clarke R; DVC Research/Research and Development Scheme: Newly Appointed Staff (NAS).

2000

  • Mechanism of local anaesthetics; Clarke R; University of Sydney/University Research Grant.

Selected publications

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Book Chapters

  • Clarke, R. (2010). Electric Field Sensitive Dyes. In Professor Alexander P Demchenko (Eds.), Advanced Fluorescence Reporters in Chemistry and Biology I: Fundamentals and Molecular Design, (pp. 331-344). Berlin Heidelberg: Springer.
  • Clarke, R. (2009). Chemotherapeutic development strategies for schistosomiasis. In Professor Ewa m. Goldys (Eds.), Fluorescence Applications in Biotechnology and the Life Sciences, (pp. 349-363). New Jersey, USA: John Wiley & Sons.

Journals

  • Lev, B., Clarke, R., Allen, T. (2014). Effects of lipid composition on biological membrane electrostatics. Biophysical Journal, 106(2, S1), 80a-80a. [More Information]
  • Khalid, M., Suliman, R., Ahmed, R., Salim, H., Clarke, R. (2014). The high and low affinity binding sites of digitalis glycosides to Na,K-ATPase. Arabian Journal for Science and Engineering, 39(1), 75-85. [More Information]
  • Garcia, A., Fry, N., Karimi, K., Liu, C., Apell, H., Rasmussen, H., Clarke, R. (2013). Extracellular allosteric Na+ binding to the Na+, K+-ATPase in cardiac myocytes. Biophysical Journal, 105(12), 2695-2705. [More Information]
  • Clarke, R., Catauro, M., Rasmussen, H., Apell, H. (2013). Quantitative calculation of the role of the Na+ ,K+ -ATPase in thermogenesis. Biochimica et Biophysica Acta-Bioenergetics, 1827 (10), 1205-1212. [More Information]
  • Liu, C., Fry, N., Hamilton, E., Chia, K., Garcia, A., Karimi Galougahi, K., Figtree, G., Clarke, R., Bundgaard, H., Rasmussen, H. (2013). Redox-dependent regulation of the Na+ -K+ pump: New twists to an old target for treatment of heart failure. Journal of Molecular and Cellular Cardiology, 61, 94-101. [More Information]
  • Ching, V., Clarke, R., Rendina, L. (2013). Supramolecular beta-cyclodextrin adducts of boron-rich DNA metallointercalators containing dicarba-closo-dodecaborane(12). Inorganic Chemistry, 52(18), 10356-10367. [More Information]
  • Begum, S., Clarke, R., Ahmed, M., Begum, S., Saleh, M. (2013). Volumetric, viscosimetric and surface properties of aqueous solutions of triethylene glycol, tetraethylene glycol, and tetraethylene glycol dimethyl ether. Journal of Molecular Liquids, 177, 11-18. [More Information]
  • Trevitt, A., Reimers, J., Clarke, R., Vandenberg, J. (2012). BIOPHYSCHEM2011: A joint meeting of the Australian Society for Biophysics and the RACI Chemistry Division. Australian Journal of Chemistry: an international journal for chemical science, 65(5), 439-441. [More Information]
  • Yin, Y., Fisher, K., Nosworthy, N., Bax, D., Clarke, R., McKenzie, D., Bilek, M. (2012). Comparison on protein adsorption properties of diamond-like carbon and nitrogen-containing plasma polymer surfaces. Thin Solid Films, 520(7), 3021-3025. [More Information]
  • Garcia, A., Rasmussen, H., Apell, H., Clarke, R. (2012). Kinetic comparisons of heart and kidney Na+, K+ -ATPases. Biophysical Journal, 103(4), 677-688. [More Information]
  • Liu, C., Garcia, A., Mahmmoud, Y., Hamilton, E., Galougahi, K., Fry, N., Figtree, G., Cornelius, F., Clarke, R., Rasmussen, H. (2012). Susceptibility of β1 Na+ -K+ pump subunit to glutathionylation and oxidative inhibition depends on conformational state of pump. Journal of Biological Chemistry, 287(15), 12353-12364. [More Information]
  • Ching, V., Clifford, S., Bhadbhade, M., Clarke, R., Rendina, L. (2012). Synthesis and supramolecular studies of chiral boronated platinum(II) complexes: Insights into the molecular recognition of carboranes by beta-cyclodextrin. Chemistry: A European Journal, 18(45), 14413-14425. [More Information]
  • Clarke, R. (2011). A perspective on biophysical chemistry. Australian Journal of Chemistry: an international journal for chemical science, 64(1), 3-4.
  • Begum, S., Clarke, R., Ahmed, M., Begum, S., Saleh, M. (2011). Densities, Viscosities, and surface Tensions of the System water + Diethylene Glycol. Journal of Chemical and Engineering Data, 56(2), 303-306. [More Information]
  • Meyers, S., Cornelius, F., Apell, H., Clarke, R. (2011). Kinetics of K+ Occlusion by the Phosphoenzyme of the Na+,K+-ATPase. Biophysical Journal, 100(1), 70-79. [More Information]
  • Pisani, M., Fromm, P., Mulyana, Y., Clarke, R., Korner, H., Heimann, K., Collins, J., Keene, F. (2011). Mechanism of cytotoxicity and cellular uptake of lipophilic inert dinuclear polypyridylruthenium(II) complexes. ChemMedChem: chemistry enabling drug discovery, 6(5), 848-858. [More Information]
  • Clarke, R., Fan, X. (2011). Pumping ions. Clinical and Experimental Pharmacology and Physiology, 38(11), 726-733. [More Information]
  • Clarke, R. (2011). Rapid Reaction Kinetics: Lessons Learnt from Ion Pumps. Australian Journal of Chemistry: an international journal for chemical science, 64(1), 5-8. [More Information]
  • Hosseini, S., Bhadbhade, M., Clarke, R., Rutledge, P., Rendina, L. (2011). Synthesis, carbohydrate- and DNA-binding studies of cationic 2,2':6',2"-terpyridineplatinum(II) complexes containing N- and S-donor boronic acid ligands. Dalton Transactions: an international journal of inorganic, organometallic and bioinorganic chemistry, 40(2), 506-513.
  • Khalid, M., Cornelius, F., Clarke, R. (2010). Dual Mechanisms of Allosteric Acceleration of the Na+,K+-ATPase by ATP. Biophysical Journal, 98(10), 2290-2298. [More Information]
  • Amoroso, S., Clarke, R., Larkum, A., Quinnell, R. (2010). Electrogenic plasma membrane H+-ATPase activity using voltage sensitive dyes. Journal of Bioenergetics and Biomembranes, 42(5), 387-393. [More Information]
  • Khalid, M., Fouassier, G., Apell, H., Cornelius, F., Clarke, R. (2010). Interaction of ATP with the phosphoenzyme of the Na+,K +-ATPase. Biochemistry, 49(6), 1248-1258.
  • Noske, R., Cornelius, F., Clarke, R. (2010). Investigation of the enzymatic activity of the Na+,K+-ATPase via isothermal titration microcalorimetry. BBA - Bioenergetics, 1797 (8), 1540-1545. [More Information]
  • Ash, M., Guilfoyle, A., Clarke, R., Guss, M., Maher, M., Jormakka, M. (2010). Potassium-activated GTPase reaction in the G protein-coupled ferrous iron transporter B. Journal of Biological Chemistry, 285(19), 14594-14602. [More Information]
  • Starke-Peterkovic, T., Clarke, R. (2009). Effect of headgroup on the dipole potential of phospholipid vesicles. European Biophysics Journal, 39(1), 103-110. [More Information]
  • Clarke, R. (2009). Mechanism of allosteric effects of ATP on the kinetics of P-type ATPases. European Biophysics Journal, 39(1), 3-17. [More Information]
  • Pilotelle-Bunner, A., Cornelius, F., Sebban, P., Kuchel, P., Clarke, R. (2009). Mechanism of Mg(2+) binding in the Na+,K+ -ATPase. Biophysical Journal, 96(9), 3753-3761. [More Information]
  • Guilfoyle, A., Maher, M., Rapp, M., Clarke, R., Harrop, S., Jormakka, M. (2009). Structural basis of GDP release and gating in G protein coupled Fe(2+) transport. The EMBO Journal, 28(17), 2677-2685. [More Information]
  • Pilotelle-Bunner, A., Beaunier, P., Tandori, J., Maroti, P., Clarke, R., Sebban, P. (2009). The local electric field within phospholipid membranes modulates the charge transfer reactions in reaction centres. BBA - Bioenergetics, 1787 (8), 1039-1049. [More Information]
  • Pilotelle-Bunner, A., Matthews, J., Cornelius, F., Apell, H., Sebban, P., Clarke, R. (2008). ATP Binding Equilibria of the Na(+),K(+)-ATPase. Biochemistry, 47(49), 13103-13114. [More Information]
  • Pham, T., Clarke, R. (2008). Solvent Dependence of the Photochemistry of the Styrylpyridinium Dye RH421. The Journal of Physical Chemistry Part B: Condensed Matter, Materials, Surfaces, Interfaces and Biophysical, 112(20), 6513-6520.
  • Clarke, R., Apell, H., Kong, B. (2007). Allosteric effect of ATP on Na+,K+-ATPase conformational kinetics. Biochemistry, 46(23), 7034-7044.
  • Hansen, P., Clarke, R., Buhagiar, K., Hamilton, E., Garcia, A., White, C., Rasmussen, H. (2007). Alloxan-induced diabetes reduces sarcolemmal Na+-K+ pump function in rabbit ventricular myocytes. American Journal of Physiology: Cell Physiology, 292, C1070-C1077.
  • Vitha, M., Clarke, R. (2007). Comparison of excitation and emission ratiometric fluorescence methods for quantifying the membrane dipole potential. Biochimica et Biophysica Acta-Biomembranes, 1768, 107-114. [More Information]
  • Le Goff, G., Vitha, M., Clarke, R. (2007). Orientational polarisability of lipid membrane surfaces. BBA - Bioenergetics, 1768, 562-570. [More Information]
  • Clarke, R., Kane, D. (2007). Two gears of pumping by the sodium pump. Biophysical Journal, 93(12), 4187-4196.
  • Starke-Peterkovic, T., Turner, N., Vitha, M., Waller, M., Hibbs, D., Clarke, R. (2006). Cholesterol effect on the dipole potential of lipid membranes. Biophysical Journal, 90(11), 4060-4070. [More Information]
  • Amoroso, S., Agon, V., Starke-Peterkovic, T., McLeod, M., Apell, H., Sebban, P., Clarke, R. (2006). Photochemical behavior and Na+,K+-ATPase sensitivity of voltage-sensitive styrylpyridinium fluorescent membrane probes. Photochemistry and Photobiology, 82(2), 495-502.
  • Starke-Peterkovic, T., Clarke, R., Turner, N., Else, P. (2005). Electric field strength of membrane lipids from vertebrate species: membrane lipid composition and Na+-K+-ATPase molecular activity. American Journal of Physiology: Regulatory, Integrative and Comparative Physiology (Print), 288(3), R663-R670.
  • William, M., Vien, J., Hamilton, E., Garcia, A., Bundgaard, H., Clarke, R., Rasmussen, H. (2005). The nitric oxide donor sodium nitroprusside stimulates the Na+-K+ pump in isolated rabbit cardiac myocytes. The Journal of Physiology, 565.3(3), 815-825. [More Information]
  • Buhagiar, K., Hansen, P., Kong, B., Clarke, R., Fernandes, C., Rasmussen, H. (2004). Dietary Cholesterol Alters Na+/K+ Selectivity At Intracellular Na+/K+ Pump Sites In Cardiac Myocytes. American Journal of Physiology: Cell Physiology, 286(2), C398-C405.
  • Clarke, R., Oprysa, A. (2004). Fluorescence And Light Scattering. Journal of Chemical Education, 81(5), 705-707.
  • Kong, B., Clarke, R. (2004). Identification Of Potential Regulatory Sites Of The Na+,K+-Atpase By Kinetic Analysis. Biochemistry, 43(8), 2241-2250.
  • Nieuwenburg, P., Clarke, R., Cai, Z., Chen, M., Larkum, A., Cabral, N., Ghiggino, K., Reimers, J. (2003). Examination of the photophysical processes of chlorophyll d leading to a clarificaiton of proposed uphill energy transfer processess in cells of Acaryochloris marina. Photochemistry and Photobiology, 77(6), 628-637.
  • Wang, Y., Winnik, F., Clarke, R. (2003). Interaction between DMPC liposomes and HM-PNIPAM polymer. Biophysical Chemistry, 104(2), 449-458.
  • Clarke, R., Humphrey, P., Lupfert, C., Apell, H., Cornelius, B. (2003). Kinetic investigations of the mechanism of the rate-determining step of the Na+, K+-ATPase pump cycle. New York Academy of Sciences. Annals, 986, 159-162.
  • Hansen, P., Buhagiar, K., Kong, B., Clarke, R., Gray, D., Rasmussen, H. (2002). Dependence of Na+-K+ pump current-voltage relationship on intracellular Na+, K+, and Cs+ in rabbit cardiac myocytes. American Journal of Physiology: Cell Physiology, 283(5), 1511-1521.
  • Schamberger, J., Clarke, R. (2002). Hydrophobic Ion Hydration and the Magnitude of the Dipole Potential. Biophysical Journal, 82(June 2002), 3081-3088.
  • Humphrey, P., Lupfert, C., Apell, H., Cornelius, F., Clarke, R. (2002). Mechanism of the Rate-Determining Step of the Na+,K+-ATPase Pump Cycle. Biochemistry, 41(30), 9496-9507.
  • Clarke, R., Bamberg, E., Fendler, K. (2001). Electrogenic properties of the Na+, K+ -ATPase probed by presteady state and relaxation studies. Journal of Bioenergetics and Biomembranes, 33, 401-405.
  • Clarke, R., Frank, J., Vater, J., Holzwarth, J. (2001). Influence of allosteric effectors on the kinetics and equilibrium binding of phosphoenolpyruvate (PEP) to phosphoenolpyruvate carboxylase (PEPC) from Zea mays. Biophysical Chemistry, 92, 53-64.
  • Lupfert, C., Grell, E., Pintschovius, V., Apell, H., Cornelius, B., Clarke, R. (2001). Rate limitation of the Na+, K+ -ATPase pump cycle. Biophysical Journal, 81(4), 2069-2081.
  • Clarke, R. (2001). The dipole potential of phospholipid membranes and methods for its detection. Advances in Colloid and Interface Science, 89-90, 263-281.

Magazine / Newspaper Articles

  • Clarke, R. (2013). When the going gets hot. Chemistry in Australia, June 2013.

2014

  • Lev, B., Clarke, R., Allen, T. (2014). Effects of lipid composition on biological membrane electrostatics. Biophysical Journal, 106(2, S1), 80a-80a. [More Information]
  • Khalid, M., Suliman, R., Ahmed, R., Salim, H., Clarke, R. (2014). The high and low affinity binding sites of digitalis glycosides to Na,K-ATPase. Arabian Journal for Science and Engineering, 39(1), 75-85. [More Information]

2013

  • Garcia, A., Fry, N., Karimi, K., Liu, C., Apell, H., Rasmussen, H., Clarke, R. (2013). Extracellular allosteric Na+ binding to the Na+, K+-ATPase in cardiac myocytes. Biophysical Journal, 105(12), 2695-2705. [More Information]
  • Clarke, R., Catauro, M., Rasmussen, H., Apell, H. (2013). Quantitative calculation of the role of the Na+ ,K+ -ATPase in thermogenesis. Biochimica et Biophysica Acta-Bioenergetics, 1827 (10), 1205-1212. [More Information]
  • Liu, C., Fry, N., Hamilton, E., Chia, K., Garcia, A., Karimi Galougahi, K., Figtree, G., Clarke, R., Bundgaard, H., Rasmussen, H. (2013). Redox-dependent regulation of the Na+ -K+ pump: New twists to an old target for treatment of heart failure. Journal of Molecular and Cellular Cardiology, 61, 94-101. [More Information]
  • Ching, V., Clarke, R., Rendina, L. (2013). Supramolecular beta-cyclodextrin adducts of boron-rich DNA metallointercalators containing dicarba-closo-dodecaborane(12). Inorganic Chemistry, 52(18), 10356-10367. [More Information]
  • Begum, S., Clarke, R., Ahmed, M., Begum, S., Saleh, M. (2013). Volumetric, viscosimetric and surface properties of aqueous solutions of triethylene glycol, tetraethylene glycol, and tetraethylene glycol dimethyl ether. Journal of Molecular Liquids, 177, 11-18. [More Information]
  • Clarke, R. (2013). When the going gets hot. Chemistry in Australia, June 2013.

2012

  • Trevitt, A., Reimers, J., Clarke, R., Vandenberg, J. (2012). BIOPHYSCHEM2011: A joint meeting of the Australian Society for Biophysics and the RACI Chemistry Division. Australian Journal of Chemistry: an international journal for chemical science, 65(5), 439-441. [More Information]
  • Yin, Y., Fisher, K., Nosworthy, N., Bax, D., Clarke, R., McKenzie, D., Bilek, M. (2012). Comparison on protein adsorption properties of diamond-like carbon and nitrogen-containing plasma polymer surfaces. Thin Solid Films, 520(7), 3021-3025. [More Information]
  • Garcia, A., Rasmussen, H., Apell, H., Clarke, R. (2012). Kinetic comparisons of heart and kidney Na+, K+ -ATPases. Biophysical Journal, 103(4), 677-688. [More Information]
  • Liu, C., Garcia, A., Mahmmoud, Y., Hamilton, E., Galougahi, K., Fry, N., Figtree, G., Cornelius, F., Clarke, R., Rasmussen, H. (2012). Susceptibility of β1 Na+ -K+ pump subunit to glutathionylation and oxidative inhibition depends on conformational state of pump. Journal of Biological Chemistry, 287(15), 12353-12364. [More Information]
  • Ching, V., Clifford, S., Bhadbhade, M., Clarke, R., Rendina, L. (2012). Synthesis and supramolecular studies of chiral boronated platinum(II) complexes: Insights into the molecular recognition of carboranes by beta-cyclodextrin. Chemistry: A European Journal, 18(45), 14413-14425. [More Information]

2011

  • Clarke, R. (2011). A perspective on biophysical chemistry. Australian Journal of Chemistry: an international journal for chemical science, 64(1), 3-4.
  • Begum, S., Clarke, R., Ahmed, M., Begum, S., Saleh, M. (2011). Densities, Viscosities, and surface Tensions of the System water + Diethylene Glycol. Journal of Chemical and Engineering Data, 56(2), 303-306. [More Information]
  • Meyers, S., Cornelius, F., Apell, H., Clarke, R. (2011). Kinetics of K+ Occlusion by the Phosphoenzyme of the Na+,K+-ATPase. Biophysical Journal, 100(1), 70-79. [More Information]
  • Pisani, M., Fromm, P., Mulyana, Y., Clarke, R., Korner, H., Heimann, K., Collins, J., Keene, F. (2011). Mechanism of cytotoxicity and cellular uptake of lipophilic inert dinuclear polypyridylruthenium(II) complexes. ChemMedChem: chemistry enabling drug discovery, 6(5), 848-858. [More Information]
  • Clarke, R., Fan, X. (2011). Pumping ions. Clinical and Experimental Pharmacology and Physiology, 38(11), 726-733. [More Information]
  • Clarke, R. (2011). Rapid Reaction Kinetics: Lessons Learnt from Ion Pumps. Australian Journal of Chemistry: an international journal for chemical science, 64(1), 5-8. [More Information]
  • Hosseini, S., Bhadbhade, M., Clarke, R., Rutledge, P., Rendina, L. (2011). Synthesis, carbohydrate- and DNA-binding studies of cationic 2,2':6',2"-terpyridineplatinum(II) complexes containing N- and S-donor boronic acid ligands. Dalton Transactions: an international journal of inorganic, organometallic and bioinorganic chemistry, 40(2), 506-513.

2010

  • Khalid, M., Cornelius, F., Clarke, R. (2010). Dual Mechanisms of Allosteric Acceleration of the Na+,K+-ATPase by ATP. Biophysical Journal, 98(10), 2290-2298. [More Information]
  • Clarke, R. (2010). Electric Field Sensitive Dyes. In Professor Alexander P Demchenko (Eds.), Advanced Fluorescence Reporters in Chemistry and Biology I: Fundamentals and Molecular Design, (pp. 331-344). Berlin Heidelberg: Springer.
  • Amoroso, S., Clarke, R., Larkum, A., Quinnell, R. (2010). Electrogenic plasma membrane H+-ATPase activity using voltage sensitive dyes. Journal of Bioenergetics and Biomembranes, 42(5), 387-393. [More Information]
  • Khalid, M., Fouassier, G., Apell, H., Cornelius, F., Clarke, R. (2010). Interaction of ATP with the phosphoenzyme of the Na+,K +-ATPase. Biochemistry, 49(6), 1248-1258.
  • Noske, R., Cornelius, F., Clarke, R. (2010). Investigation of the enzymatic activity of the Na+,K+-ATPase via isothermal titration microcalorimetry. BBA - Bioenergetics, 1797 (8), 1540-1545. [More Information]
  • Ash, M., Guilfoyle, A., Clarke, R., Guss, M., Maher, M., Jormakka, M. (2010). Potassium-activated GTPase reaction in the G protein-coupled ferrous iron transporter B. Journal of Biological Chemistry, 285(19), 14594-14602. [More Information]

2009

  • Clarke, R. (2009). Chemotherapeutic development strategies for schistosomiasis. In Professor Ewa m. Goldys (Eds.), Fluorescence Applications in Biotechnology and the Life Sciences, (pp. 349-363). New Jersey, USA: John Wiley & Sons.
  • Starke-Peterkovic, T., Clarke, R. (2009). Effect of headgroup on the dipole potential of phospholipid vesicles. European Biophysics Journal, 39(1), 103-110. [More Information]
  • Clarke, R. (2009). Mechanism of allosteric effects of ATP on the kinetics of P-type ATPases. European Biophysics Journal, 39(1), 3-17. [More Information]
  • Pilotelle-Bunner, A., Cornelius, F., Sebban, P., Kuchel, P., Clarke, R. (2009). Mechanism of Mg(2+) binding in the Na+,K+ -ATPase. Biophysical Journal, 96(9), 3753-3761. [More Information]
  • Guilfoyle, A., Maher, M., Rapp, M., Clarke, R., Harrop, S., Jormakka, M. (2009). Structural basis of GDP release and gating in G protein coupled Fe(2+) transport. The EMBO Journal, 28(17), 2677-2685. [More Information]
  • Pilotelle-Bunner, A., Beaunier, P., Tandori, J., Maroti, P., Clarke, R., Sebban, P. (2009). The local electric field within phospholipid membranes modulates the charge transfer reactions in reaction centres. BBA - Bioenergetics, 1787 (8), 1039-1049. [More Information]

2008

  • Pilotelle-Bunner, A., Matthews, J., Cornelius, F., Apell, H., Sebban, P., Clarke, R. (2008). ATP Binding Equilibria of the Na(+),K(+)-ATPase. Biochemistry, 47(49), 13103-13114. [More Information]
  • Pham, T., Clarke, R. (2008). Solvent Dependence of the Photochemistry of the Styrylpyridinium Dye RH421. The Journal of Physical Chemistry Part B: Condensed Matter, Materials, Surfaces, Interfaces and Biophysical, 112(20), 6513-6520.

2007

  • Clarke, R., Apell, H., Kong, B. (2007). Allosteric effect of ATP on Na+,K+-ATPase conformational kinetics. Biochemistry, 46(23), 7034-7044.
  • Hansen, P., Clarke, R., Buhagiar, K., Hamilton, E., Garcia, A., White, C., Rasmussen, H. (2007). Alloxan-induced diabetes reduces sarcolemmal Na+-K+ pump function in rabbit ventricular myocytes. American Journal of Physiology: Cell Physiology, 292, C1070-C1077.
  • Vitha, M., Clarke, R. (2007). Comparison of excitation and emission ratiometric fluorescence methods for quantifying the membrane dipole potential. Biochimica et Biophysica Acta-Biomembranes, 1768, 107-114. [More Information]
  • Le Goff, G., Vitha, M., Clarke, R. (2007). Orientational polarisability of lipid membrane surfaces. BBA - Bioenergetics, 1768, 562-570. [More Information]
  • Clarke, R., Kane, D. (2007). Two gears of pumping by the sodium pump. Biophysical Journal, 93(12), 4187-4196.

2006

  • Starke-Peterkovic, T., Turner, N., Vitha, M., Waller, M., Hibbs, D., Clarke, R. (2006). Cholesterol effect on the dipole potential of lipid membranes. Biophysical Journal, 90(11), 4060-4070. [More Information]
  • Amoroso, S., Agon, V., Starke-Peterkovic, T., McLeod, M., Apell, H., Sebban, P., Clarke, R. (2006). Photochemical behavior and Na+,K+-ATPase sensitivity of voltage-sensitive styrylpyridinium fluorescent membrane probes. Photochemistry and Photobiology, 82(2), 495-502.

2005

  • Starke-Peterkovic, T., Clarke, R., Turner, N., Else, P. (2005). Electric field strength of membrane lipids from vertebrate species: membrane lipid composition and Na+-K+-ATPase molecular activity. American Journal of Physiology: Regulatory, Integrative and Comparative Physiology (Print), 288(3), R663-R670.
  • William, M., Vien, J., Hamilton, E., Garcia, A., Bundgaard, H., Clarke, R., Rasmussen, H. (2005). The nitric oxide donor sodium nitroprusside stimulates the Na+-K+ pump in isolated rabbit cardiac myocytes. The Journal of Physiology, 565.3(3), 815-825. [More Information]

2004

  • Buhagiar, K., Hansen, P., Kong, B., Clarke, R., Fernandes, C., Rasmussen, H. (2004). Dietary Cholesterol Alters Na+/K+ Selectivity At Intracellular Na+/K+ Pump Sites In Cardiac Myocytes. American Journal of Physiology: Cell Physiology, 286(2), C398-C405.
  • Clarke, R., Oprysa, A. (2004). Fluorescence And Light Scattering. Journal of Chemical Education, 81(5), 705-707.
  • Kong, B., Clarke, R. (2004). Identification Of Potential Regulatory Sites Of The Na+,K+-Atpase By Kinetic Analysis. Biochemistry, 43(8), 2241-2250.

2003

  • Nieuwenburg, P., Clarke, R., Cai, Z., Chen, M., Larkum, A., Cabral, N., Ghiggino, K., Reimers, J. (2003). Examination of the photophysical processes of chlorophyll d leading to a clarificaiton of proposed uphill energy transfer processess in cells of Acaryochloris marina. Photochemistry and Photobiology, 77(6), 628-637.
  • Wang, Y., Winnik, F., Clarke, R. (2003). Interaction between DMPC liposomes and HM-PNIPAM polymer. Biophysical Chemistry, 104(2), 449-458.
  • Clarke, R., Humphrey, P., Lupfert, C., Apell, H., Cornelius, B. (2003). Kinetic investigations of the mechanism of the rate-determining step of the Na+, K+-ATPase pump cycle. New York Academy of Sciences. Annals, 986, 159-162.

2002

  • Hansen, P., Buhagiar, K., Kong, B., Clarke, R., Gray, D., Rasmussen, H. (2002). Dependence of Na+-K+ pump current-voltage relationship on intracellular Na+, K+, and Cs+ in rabbit cardiac myocytes. American Journal of Physiology: Cell Physiology, 283(5), 1511-1521.
  • Schamberger, J., Clarke, R. (2002). Hydrophobic Ion Hydration and the Magnitude of the Dipole Potential. Biophysical Journal, 82(June 2002), 3081-3088.
  • Humphrey, P., Lupfert, C., Apell, H., Cornelius, F., Clarke, R. (2002). Mechanism of the Rate-Determining Step of the Na+,K+-ATPase Pump Cycle. Biochemistry, 41(30), 9496-9507.

2001

  • Clarke, R., Bamberg, E., Fendler, K. (2001). Electrogenic properties of the Na+, K+ -ATPase probed by presteady state and relaxation studies. Journal of Bioenergetics and Biomembranes, 33, 401-405.
  • Clarke, R., Frank, J., Vater, J., Holzwarth, J. (2001). Influence of allosteric effectors on the kinetics and equilibrium binding of phosphoenolpyruvate (PEP) to phosphoenolpyruvate carboxylase (PEPC) from Zea mays. Biophysical Chemistry, 92, 53-64.
  • Lupfert, C., Grell, E., Pintschovius, V., Apell, H., Cornelius, B., Clarke, R. (2001). Rate limitation of the Na+, K+ -ATPase pump cycle. Biophysical Journal, 81(4), 2069-2081.
  • Clarke, R. (2001). The dipole potential of phospholipid membranes and methods for its detection. Advances in Colloid and Interface Science, 89-90, 263-281.

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