Areas of expertise
- Biological Physics 029901
- Plant Cell And Molecular Biology 060702
- Structural Chemistry And Spectroscopy 030606
- Enzymes 060107
- Physical Chemistry (Incl. Structural) 0306
Biography
My research career has focused on the study of biological and biomimetic enzymes using magneto-optical and magnetic resonance techniques. My research interests span: exciton coupling within large pigment assemblies, the spectroscopy of transition metals, particularly with regard to metallocofactors, electron transfer within the biological photosynthetic apparatus and more recently, the development of synthetic enzymes and catalysts.
I have experience in: (magnetic) circular dichroism, continuous wave and pulsed Electron paramagnetic resonance (EPR) and FT-infrared spectroscopy. I am also interested in the development of effective models and computational simulation in all these fields. Current research highlights include:
(i) The first spectroscopic characterization of the di-manganese ribonucleotide reductase (Mn-RNR). Our multifrequency study (9 GHz, 34 GHz and 244 GHz) on the Mn-RNR, together with the work of Joanne Stubbe (MIT) has allowed the mechanism of metallocofactor assembly to be resolved.
(ii) Detection of substrate (water) binding to the the oxygen evolving complex (OEC) of Photosystem II (PS II) in the S1/S2 state using high field (94 GHz) EPR/EDNMR spectroscopy and isotopic (17O) labeling. These experiments suggest that the slow exchanging substrate in the S1/S2 state is a μ-oxo bridge of the tetramanganese cluster.
(iii) The first electronic structural model of the OEC of PSII in its catalytic state prior to O-O bond formation. Our work on the OEC (multifrequency EPR/55Mn EDNMR/ENDOR) resolves the structure of the tetra-manganese cluster support oxo/oxyl coupling mechanism for O-O bond formation in S4.
Publications
- Schuller, J, Birrell, J, Tanaka, H et al. 2019, 'Structural adaptations of photosynthetic complex I enable ferredoxin-dependent electron transfer', Science, vol. 363, no. 6424, pp. 257-260.
- Sun, Q, Zhang, S, Cortie, D et al. 2019, 'Highly Efficient Visible Light Catalysts Driven by Ti3+-V-O-2Ti(4+)-N3- Defect Clusters', ChemNanoMat, vol. 5, no. 2, pp. 169-174.
- Chrysina, M, Heyno, E, Kutin, Y et al. 2019, 'Five-coordinate MnIV intermediate in the activation of nature?s water splitting cofactor', PNAS - Proceedings of the National Academy of Sciences of the United States of America, vol. 116, no. 34, pp. 16841-16846.
- Möbius, K, Lubitz, W, Cox, N et al. 2018, 'Biomolecular EPR Meets NMR at High Magnetic Fields', Magnetochemistry, vol. 4, no. 50, pp. 1-85.
- Bhargava, S, Bansal, V, Singh, M et al. 2018, 'Oxygen-deficient photostable Cu2O for enhanced visible light photocatalytic activity', Nanoscale, vol. 10, no. 13, pp. 6039-6050pp.
- Srinivas , V, Lebrette, H, Lundin, D et al. 2018, 'Metal-free ribonucleotide reduction powered by a DOPA radical in Mycoplasma pathogens', Nature, vol. 563, pp. 416-420pp.
- Zhang, J, Launay, K, Hill, N et al. 2018, 'Disubstituted Aminoanthraquinone-Based Photoinitiators for Free Radical Polymerization and Fast 3D Printing under Visible Light', Macromolecules, vol. 51, pp. 10104-10112.
- Morton, J, Chrysina, M, Craig, V et al 2017, 'Structured near-infrared Magnetic Circular Dichroism spectra of the Mn4CaO5 cluster of PSII in T. vulcanus are dominated by Mn(IV) d-d 4A to 2E spin-flip transitions', Biochimica et Biophysica Acta: Bioenergetics, vol. 1859, pp. 88-98.
- Decaneto, E, Vasilevskaya, T, Kutin, Y et al. 2017, 'Solvent water interactions within the active site of the membrane type I matrix metalloproteinase', Physical Chemistry Chemical Physics, vol. 19, no. 45, pp. 30316-30331.
- Paul, S, Cox, N & Pantazis, D 2017, 'What Can We Learn from a Biomimetic Model of Nature's Oxygen-Evolving Complex?', Inorganic Chemistry, vol. 56, no. 7, pp. 3875-3888pp.
- Cox, N, Nalepa, A, Lubitz, W et al. 2017, 'ELDOR-detected NMR: A general and robust method for electron-nuclear hyperfine spectroscopy?', Journal of Magnetic Resonance, vol. 280, pp. 63-78.
- Lohmiller, T, Krewald, V, Sedoud, A et al. 2017, 'The First State in the Catalytic Cycle of the Water-Oxidizing Enzyme: Identification of a Water-Derived µ-Hydroxo Bridge', Journal of the American Chemical Society, vol. 139, no. 41, pp. 14412-14424.
- Perez-Navarro, M, Neese, F, Lubitz, W et al. 2016, 'Recent developments in biological water oxidation', Current Opinion in Chemical Biology, vol. 31, pp. 113-119.
- Retegan, M, Krewald, V, Mamedov, F et al. 2016, 'A five-coordinate Mn(IV) intermediate in biological water oxidation: spectroscopic signature and a pivot mechanism for water binding', Chemical Science, vol. 7, no. 1, pp. 72-84.
- Krewald, V, Retegan, M, Neese, F et al. 2016, 'Spin State as a Marker for the Structural Evolution of Nature's Water Splitting Catalyst', Inorganic Chemistry, vol. 55, no. 2, pp. 488-501.
- Kutin, Y, Srinivas , V, Kositzki, R et al. 2016, 'Divergent assembly mechanisms of the manganese/iron cofactors in R2lox and R2c proteins', Journal of Inorganic Biochemistry, vol. 162, no. -, pp. 164-177pp.
- Rapatskiy, L, Ames, W, Perez-Navarro, M et al. 2015, 'Characterization of Oxygen Bridged Manganese Model Complexes Using Multifrequency 17O-Hyperfine EPR Spectroscopies and Density Functional Theory', Journal of Physical Chemistry B, vol. 119, no. 43, pp. 13904-13921.
- Krewald, V, Retegan, M, Cox, N et al. 2015, 'Metal oxidation states in biological water splitting', Chemical Science, vol. 6, no. 3, pp. 1676-1695.
- Cox, N, Pantazis, D, Neese, F et al. 2015, 'Artificial photosynthesis: understanding water splitting in nature', Interface Focus, vol. 5, no. 3, pp. 1-10.
- Tang, K, Knipp, M, Liu, B et al. 2015, 'Redox-dependent Ligand Switching in a Sensory Heme-binding GAF Domain of the Cyanobacterium Nostoc sp. PCC7120', Journal of Biological Chemistry, vol. 290, no. 31, pp. 19067-19080.
- He, C, Howes, B, Smulevich, G et al. 2015, 'Nitrite Dismutase Reaction Mechanism: Kinetic and Spectroscopic Investigation of the Interaction between Nitrophorin and Nitrite', Journal of the American Chemical Society, vol. 137, no. 12, pp. 4141-4150.
- Cox, N, Nalepa, A, Pandelia, M et al 2015, 'Chapter Nine “Pulse Double-Resonance EPR Techniques for the Study of Metallobiomolecules', in Peter Z. Qin and Kurt Warncke (ed.), Methods in Enzymology: Electron Paramagnetic Resonance Investigations of Biological Systems by Using Spin Labels, Spin Probes, and Intrinsic Metal Ions, Part A, Elsevier Inc., Massachusetts, pp. 211-249.
- Cox, N, Retegan, M, Neese, F et al. 2014, 'Electronic structure of the oxygenevolving complex in photosystem II prior to O-O bond formation', Science, vol. 345, no. 6198, pp. 804-808.
- Lohmiller, T, Krewald, V, Perez-Navarro, M et al. 2014, 'Structure, ligands and substrate coordination of the oxygen-evolving complex of photosystem II in the S2 state: a combined EPR and DFT study', Physical Chemistry Chemical Physics, vol. 16, no. 24, pp. 11877-11892.
- Pantazis, D, Cox, N, Lubitz, W et al. 2014, 'Oxygen-evolving Photosystem II', in Robert A. Scott (ed.), Encyclopedia of Inorganic and Bioinorganic Chemistry, John Wiley and Sons Inc., Online, pp. 1-13pp.
- Retegan, M, Cox, N, Lubitz, W et al. 2014, 'The first tyrosyl radical intermediate formed in the S2-S3 transition of photosystem II', Physical Chemistry Chemical Physics, vol. 16, no. 24, pp. 11901-11910.
- Retegan, M, Cox, N, Pantazis, D et al. 2014, 'A First-Principles Approach to the Calculation of the on-Site Zero-Field Splitting in Polynuclear Transition Metal Complexes', Inorganic Chemistry, vol. 53, no. 21, pp. 11785-11793.
- Sugiura, M, Ozaki, Y, Nakamura, M et al. 2014, 'The D1-173 amino acid is a structural determinant of the critical interaction between D1-Tyr161 (TyrZ) and D1-His190 in Photosystem II', Biochimica et Biophysica Acta: Bioenergetics, vol. 1837, no. 12, pp. 1922-1931.
- Shafaat, H, Griese, J, Pantazis, D et al 2014, 'Electronic Structural Flexibility of Heterobimetallic Mn/Fe Cofactors: R2lox and R2c Proteins', Journal of the American Chemical Society, vol. 36, no. 38, pp. 13399-13409.
- Lohmiller, T, Ames, W, Lubitz, W et al. 2013, 'EPR Spectroscopy and the electronic structure of the Oxygen-Evolving Complex of Photosystem II', Applied Magnetic Resonance, vol. 44, no. 6, pp. 691-720.
- Cox, N & Messinger, J 2013, 'Reflections on substrate water and dioxygen formation', Biochimica et Biophysica Acta: Bioenergetics, vol. 1827, no. 8-9, pp. 1020-1030.
- Cox, N, Lubitz, W & Savitsky, A 2013, 'W-band ELDOR-detected NMR (EDNMR) spectroscopy as a versatile technique for the characterisation of transition metal-ligand interactions', Molecular Physics, vol. 111, no. 18-19, pp. 2788-2808.
- Perez-Navarro, M, Ames, W, Nisson, H et al. 2013, 'Ammonia binding to the oxygen-evolving complex of photosystem II identifies the solvent-exchangeable oxygen bridge (μ-oxo) of the manganese tetramer', PNAS - Proceedings of the National Academy of Sciences of the United States of America, vol. 110, no. 39, pp. 15561-15566.
- Cox, N, Pantazis, D, Neese, F et al. 2013, 'Biological Water Oxidation', Accounts of Chemical Research, vol. 46, no. 7, pp. 1588-1596.
- Cox, N & Lubitz, W 2013, 'Molecular concepts of water splitting: Nature's approach', Green, vol. 3, no. 5-6, pp. 235-263.
- Griese, J, Roos, K, Cox, N et al 2013, 'Structurally Encoded Metal Discrimination and Ether Bond Formation in a Heterodinuclear Metalloprotein', PNAS - Proceedings of the National Academy of Sciences of the United States of America, vol. 110, no. 43, pp. 17189-17194.
- Lohmiller, T, Cox, N, Su, J et al. 2012, 'The basic properties of the electronic structure of the oxygen-evolving complex of photosystem II are not perturbed by Ca2+ removal', Journal of Biological Chemistry, vol. 287, no. 29, pp. 24721-24733.
- Rapatskiy, L, Cox, N, Savitsky, A et al. 2012, 'Detection of the Water-Binding Sites of the Oxygen-Evolving Complex of Photosystem II Using W-Band 17O Electron-Electron Double Resonance-Detected NMR Spectroscopy', Journal of the American Chemical Society, vol. 134, no. 40, pp. 16619-16634.
- Cardona, T, Sedoud, A, Cox, N et al. 2012, 'Charge separation in Photosystem II: A comparative and evolutionary overview', Biochimica et Biophysica Acta: Bioenergetics, vol. 1817, no. 1, pp. 26-43.
- Kolling, D, Cox, N, Ananyev, G et al. 2012, 'What are the oxidation states of manganese required to catalyze photosynthetic water oxidation?', Biophysical Journal, vol. 103, no. 2, pp. 313-322.
- Pantazis, D, Ames, W, Cox, N et al 2012, 'Two Interconvertible Structures that Explain the Spectroscopic Properties of the Oxygen-Evolving Complex of Photosystem II in the S2 State', Angewandte Chemie International Edition, vol. 51, pp. 9935 -9940.
- Su, J, Cox, N, Ames, W et al. 2011, 'The electronic structures of the S2 states of the oxygen-evolving complexes of photosystem II in plants and cyanobacteria in the presence and absence of methanol', Biochimica et Biophysica Acta: Bioenergetics, vol. 1807, no. 7, pp. 829-840.
- Cox, N, Ames, W, Epel, B et al. 2011, 'Electronic structure of a Weakly Antiferromagnetically Coupled MnIIMnIII Model Relevant to Manganese Proteins: A Combined EPR, 55Mn-ENDOR, and DFT study', Inorganic Chemistry, vol. 50, no. 17, pp. 8238-8251.
- Sedoud, A, Kastner, L, Cox, N et al. 2011, 'Effects of formate binding on the quinone-iron electron acceptor complex of photosystem II', Biochimica et Biophysica Acta: Bioenergetics, vol. 1807, no. 2, pp. 216-226.
- Cox, N, Rapatskiy, L, Su, J et al. 2011, 'Effect of Ca2+/Sr2+ substitution on the electronic structure of the oxygen-evolving complex of photosystem II: A combined multifrequency EPR, 55Mn-ENDOR, and DFT study of the S2 state', Journal of the American Chemical Society, vol. 133, no. 10, pp. 3635-3648.
- Ames, W, Pantazis, D, Krewald, V et al. 2011, 'Theoretical evaluation of structural models of the S2 state in the oxygen evolving complex of photosystem II: Protonation states and magnetic interactions', Journal of the American Chemical Society, vol. 133, no. 49, pp. 19743-19757.
- Sedoud, A, Cox, N, Sugiura, M et al 2011, 'Semiquinone-iron complex of Photosystem II: EPR signals assigned to the low-field edge of the ground state doublet of QA-Fe2+ and QB-Fe2+', Biochemistry, vol. 50, no. 27, pp. 6012-6021.
- Cox, N, Ogata, H, Stolle, P et al. 2010, 'A tyrosyl-dimanganese coupled spin system is the native metalloradical cofactor of the R2F subunit of the ribonucleotide reductase of corynebacterium ammoniagenes', Journal of the American Chemical Society, vol. 132, no. 32, pp. 11197-11213.
- Stolle, P, Barckhausen, O, Oehlmann, W et al. 2010, 'Homologous expression of the nrdF gene of Corynebacterium ammoniagenes strain ATCC 6872 generates a manganese-metallocofactor (R2F) and a stable tyrosyl radical (Y.) involved in ribonucleotide reduction', The FEBS Journal, vol. 277, no. 23, pp. 4849-4862.
- Herrero, C, Hughes, J, Quaranta, A et al. 2010, 'Intramolecular light induced activation of a Salen-MnIII complex by a ruthenium photosensitizer', Chemical Communications, vol. 46, no. 40, pp. 7605-7607.
- Hughes, J, Cox, N, Rutherford, A et al. 2010, 'D1 protein variants in Photosystem II from Thermosynechococcus elongatus studied by low temperature optical spectroscopy', Biochimica et Biophysica Acta: Bioenergetics, vol. 1797, no. 1, pp. 11-19.
- Cox, N, Hughes, J, Rutherford, A et al. 2010, 'On the assignment of PSHB in D1/D2/cytb559 reaction centers', Physics Procedia, vol. 3, no. 4, pp. 1601-1605.
- Cox, N, Hughes, J, Steffen, R et al. 2009, 'Identification of the QY Excitation of the Primary Electron Acceptor of Photosystem II: CD Determination of Its Coupling Environment', Journal of Physical Chemistry B, vol. 113, no. 36, pp. 12364-12374.
- Cox, N, Jin, L, Jaszewski, A et al. 2009, 'The semiquinone-iron complex of Photosystem II: structural insights from ESR and theoretical simulation; evidence that the native ligand to the non-heme iron is carbonate.', Biophysical Journal, vol. 97, no. 7, pp. 2024-2033.
- Cox, N, Ho, F, Pewnim, N et al. 2009, 'The S1 split signal of photosystem II; a tyrosine-manganese coupled interaction', Biochimica et Biophysica Acta: Bioenergetics, vol. 1787, no. 7, pp. 882-889.
- Conlan, B, Cox, N, Su, J et al. 2009, 'Photo-catalytic oxidation of a di-nuclear manganese centre in an engineered bacterioferritin 'reaction centre'', Biochimica et Biophysica Acta: Bioenergetics, vol. 1787, no. 9, pp. 1112-1121.
- Cox, N, Hughes, J, Steffen, R et al. 2008, 'The primary electron acceptor of photosystem II is weakly coupled to the accessory chlorophyll', in Allen, J. F., Gantt, E., Golbeck, J. H., Osmond, B. (ed.), Photosynthesis. Energy from the Sun: 14th International Congress on Photosynthesis 2007, Springer, Dordrecht, pp. 43-46.
- Hughes, J, Steffen, R, Cox, N et al. 2008, 'What is the origin of the highly dispersive quantum efficiencies for secondary donor oxidation at low temperature in photosystem II?', in Allen, J. F., Gantt, E., Golbeck, J. H., Osmond, B. (ed.), Photosynthesis. Energy from the Sun: 14th International Congress on Photosynthesis 2007, Springer, Dordrecht, pp. 85-88.
- Krausz, E, Cox, N & Arskold , S 2008, 'Spectral characteristics of PS II reaction centres: as isolated preparations and when integral to PS II core complexes', Photosynthesis Research, vol. 98, no. 1-3, pp. 207-217.
- Steffen, R, Hughes, J, Cox, N et al. 2008, 'Low temperature secondary pathway donation in Photosystem II of spinach', in Allen, J. F., Gantt, E., Golbeck, J. H., Osmond, B. (ed.), Photosynthesis. Energy from the Sun: 14th International Congress on Photosynthesis 2007, Springer, Dordrecht, pp. 201-206.
- Fischer, G, Cao, X, Francis, M et al. 2005, 'The FT-IR spectra of glycine and glycylglycine zwitterions isolated in alkali halide matrices', Chemical Physics, vol. 313, pp. 39-49.
Projects and Grants
Grants information is drawn from ARIES. To add or update Projects or Grants information please contact your College Research Office.
- Photosynthesis under extreme conditions (Primary Investigator)
- Ultrafast magic angle spinning solid-state NMR capability (Secondary Investigator)
- Australian High Field EPR Facility (Primary Investigator)
- Designing reactivity of homogeneous and heterogeneous water-splitting catalysts using muti-dimensionalsite-selective spectroscopies (Primary Investigator)
