huntern

Prof Neil Hunter FRS
Krebs Chair in Biochemistry

Room: E14a
0114 222 4191
c.n.hunter@sheffield.ac.uk

General

Career History

  • 1978 - 1979: Busch Postdoctoral Fellow, Dept of Microbiology, Rutgers University, N.J., U.S.A.
  • 1979 - 1980: Research Assistant Professor, Dept. of Biochemistry, Rutgers University, N.J., USA.
  • 1981 - 1982: SERC Postdoctoral Fellow, Department of Biochemistry, Bristol University.
  • 1983 - 1984: Postdoctoral Research Assistant, Department of Microbiology, Bristol University.
  • 1984 - 1988: Lecturer, Department of Pure and Applied Biology, Imperial College, London.
  • 1986: Visiting EMBO Fellow, Department of Biophysics, Leiden University, The Netherlands.
  • 1986: Visiting Faculty Fellow, Department of Biochemistry, Rutgers University, N.J., U.S.A.
  • 1988 - 1990: Senior Lecturer, Dept of Mol. Biology and Biotechnology (MBB), Sheffield University.
  • 1990 - 1993: Reader, MBB, Sheffield University.
  • 1993 - 2008: Professor, MBB, Sheffield University.
  • 2008 - present: Krebs Professor of Biochemistry, MBB, Sheffield University

Honours and Distinctions

  • 1978 - 80: Charles and Joanna Busch Postdoctoral Fellowship, Rutgers University, NJ, USA
  • 1980 - 82: SRC Postdoctoral Fellowship, Department of Biochemistry, Bristol University
  • 1986: Visiting EMBO Fellowship, Dept Biophysics, Leiden University, The Netherlands
  • 1996: D.Sc, Bristol University
  • 2003: Delivered The Drummond Lecture, Queen Mary College, London
  • 2007: Delivered The Neuberger Lecture, Novartis Foundation, London
  • 2009: Elected to the Fellowship of the Royal Society
  • 2012: Honorary Professor, Qinqdao Institute of Bioenergy and Bioprocess Technology
  • 2012: Chinese Academy of Sciences: Visiting Professorship for Senior International Scientists
  • 2013: Delivered the 21st Masters Distinguished Lecture, Shanghai JiaoTong University
  • 2013 - 16: Honorary Professor, Shanghai JiaoTong University.
  • 2013 - 18: European Research Council Advanced Award
  • 2014: Delivered the Inspiring Wisdom Distinguished Lecture, Shanghai JiaoTong University.
  • 2015: Delivered the Joel Mandelstam Lecture, Department of Biochemistry, University of Oxford
  • 2018: Biochemical Society Keilin Memorial Lecture

Research Keywords

Photosynthesis, microbiology, chlorophyll, phototrophic bacteria, cyanobacteria, carotenoids, light-harvesting complexes, reaction centres, membrane proteins, biochemistry, enzymology, nanotechnology, atomic force microscopy

Research

Photosynthesis is essential for life on Earth. It starts with the collection of solar energy by the protein-bound chlorophyll and carotenoid pigments of light-harvesting (LH) complexes, which absorb and transfer this energy to reaction centres (RCs) where it is trapped, before conversion to a form of energy useful for the cell. We exploit the relative simplicity of photosynthetic bacteria to study the biosynthesis of these pigments, and the assembly, structure and membrane organisation of LH and RC pigment-protein complexes. We use a variety of approaches - molecular genetics, protein engineering, atomic force microscopy as well as structural and spectroscopic methods - for our studies of the biogenesis, structure and function of photosynthetic membranes. In addition we are fortunate to have collaborations with many scientists in Sheffield, Europe, the USA and China.


Chlorophyll biosynthesis in bacteria and plants

Chlorophyll (Chl) biosynthesis is the most productive biochemical pathway on Earth, synthesising billions of tonnes of Chl per annum on land and in the oceans. We have cloned and sequenced many of the genes for this biosynthetic pathway, from Rhodobacter sphaeroides, the cyanobacterium Synechocystis, and from the model plant Arabidopsis thaliana and have been successful in overproducing many of them in an active form in E. coli. We study the enzymology and regulation of this pathway; in particular, we are characterising the mechanism of the first committed step of chlorophyll biosynthesis, magnesium chelatase, as well as the enzyme that catalyses the light-driven step in the pathway, protochlorophyllide reductase.

fig1

Figure 1: The first step in chlorophyll biosynthesis involves the insertion of a magnesium ion into protoporphyrin. This reaction is catalysed by a multisubunit enzyme complex comprising the Chl H, I and D subunits, and it is driven by the hydrolysis of 15 ATP molecules.

Selected Publications

Sobotka, R., Tichy, M., Wilde, A. and Hunter, C.N. (2011) Functional assignments for the C-terminal domains of the ferrochelatase from Synechocystis PCC6803: the CAB domain plays a regulatory role and region II is essential for catalysis. Plant Physiol. 155, 1735-1747.

Davison, P.A and Hunter, C.N. (2011) Abolition of magnesium chelatase activity by the gun5 mutation and reversal by Gun4. FEBS Lett 585 183-186.

Jaschke, P. R., Hardjasa, A., Digby, E.L., Hunter, C.N. and Beatty, J.T. (2011) A bchD (Mg chelatase) mutant of Rhodobacter sphaeroides synthesizes zinc-bacteriochlorophyll through novel zinc-containing intermediates. J Biol Chem 286, 20313-20322.

Qian, P., Marklew, C.J., Viney, J., Davison, P.A., Brindley, A.A., Soderberg, C., Al-Karadaghi, S., Grossmann, J.G., Bullough, P.A. and Hunter, C.N. (2012) Structure of the cyanobacterial Mg chelatase H subunit determined by single particle reconstruction and small-angle X-ray scattering. J Biol Chem. 287, 4946-4956.

Hollingshead, S., Kopečná, J., Jackson, P.J., Canniffe, D.P., Davison, P.A., Dickman, M.J., Sobotka, R. and Hunter, C.N. (2012) Conserved chloroplast open-reading frame ycf54 is required for activity of the magnesium protoporphyrin monomethylester oxidative cyclase in Synechocystis PCC 6803. J Biol. Chem. 287, 27823–27833.

Canniffe, D.P., Jackson, P.J., Hollingshead, S., Dickman, M.J. and Hunter, C.N. (2013) Identification of an 8-vinyl reductase involved in bacteriochlorophyll biosynthesis in Rhodobacter sphaeroides and evidence for the existence of a third distinct form of the enzyme. Biochem J. 450 (part 2), 397-405.

Adams, N.B.P., Marklew, C.J., Brindley, A.A., Hunter, C.N. and Reid, J.D. (2014) Characterization of the magnesium chelatase from Thermosynechococcus elongatus. Biochem J. 457, 163-170.

Canniffe, D.P. Chidgey, J.W. and Hunter, C.N. (2014) Elucidation of the preferred routes of C8-vinyl reduction in chlorophyll and bacteriochlorophyll biosynthesis. Biochemical Journal 462, 463-440.

Canniffe, D.P. and Hunter, C.N. (2014) Engineered biosynthesis of bacteriochlorophyll b in Rhodobacter sphaeroides. Biochim. Biophys. Acta 1837, 1611-1616.

Adams, N.B.P., Marklew, C.J., Qian, P., Brindley, A.A., Davison, P.A., Bullough, P.A. and Hunter, C.N. (2014) Structural and functional consequences of removing the N-terminal domain from the magnesium chelatase ChlH subunit of Thermosynechococcus elongatus. Biochemical Journal 464 (part 3) 315-322.

Kopečná, J., de Vaca, I.C., Adams, N.B.P., Davison, P.A., Hunter, C.N., Guallar, V. and Sobotka, R. (2015) Porphyrin binding to Gun4 protein, facilitated by a flexible loop, controls metabolite flow through the chlorophyll biosynthetic pathway J. Biol. Chem. 290(47), 28477-28488.

Brindley, A.A., Adams, N.B.P., Hunter, C.N. and Reid, J.D. (2015) Five glutamic acid residues in the C-terminal domain of the ChlD subunit play a major role in conferring Mg2+ cooperativity on magnesium chelatase. Biochemistry 54 (44) 6659–6662.

Chen, G.E., Hitchcock, A., Jackson, P.J., Dickman, M.J., Hunter, C.N. and Canniffe, D.P. (2016) Two unrelated 8-vinyl reductases ensure production of mature chlorophylls in Acaryochloris marina. J. Bacteriol. 198(9) 1393-1400.

Adams, N.B.P., Vasilev, C., Brindley, A.A., Hunter, C.N. (2016) Nanomechanical and thermophoretic analyses of the nucleotide- dependent interaction forces between the AAA+ subunits of magnesium chelatase. J. Am. Chem. Soc. 138 (20) 6591-6597.

Adams, N.B.P., Brindley, A.A., Hunter, C.N. and Reid, J.D. (2016) The catalytic power of magnesium chelatase: a benchmark for the AAA+ ATPases. FEBS Lett. 590, 1687-1693.

Hitchcock, A., Jackson, P.J., Chidgey, J.W., Dickman, M.J. and Hunter, C.N. and Canniffe, D.P. (2016) Biosynthesis of chlorophyll a in a purple bacterial phototroph and assembly into a chlorophyll-protein complex. ACS Synth Biol DOI: 10.1021/acssynbio.6b00069.

Chen, G., Canniffe, D.P., Martin, E.C. and Hunter, C.N. (2016) Absence of the cbb3 terminal oxidase reveals an active oxidative cyclase involved in bacteriochlorophyll biosynthesis in Rhodobacter sphaeroides. J. Bacteriol. doi: 10.1128/JB.00121-16.


Protein engineering, biochemical and structural studies of light harvesting and reaction centre complexes.

We have developed a versatile system for the mutagenesis and expression of genetically altered photosynthetic complexes, which allows us to examine protein-protein and pigment-protein interactions, such as those that establish hydrogen-bonding networks that tune the light-absorbing and energy transferring properties of bacterial light-harvesting (LH) complexes. In our biochemical work we purify the LH2, LH1 and RC-LH1 and RC-LH1-PufX complexes of Rhodobacter sphaeroides and use crystallographic and single particle methods, in collaboration with Professor Per Bullough, to study their internal structure and molecular shape. The V-shape of the RC-LH1-PufX dimer complex is a striking example of a protein that imposes curvature on a cell membrane, which optimises light absorption.

fig2

Figure 2: The V-shaped RC-LH1-PufX core dimer. A, showing positions of LH1 transmembrane polypeptides; B, Surface views of the 3-D reconstruction of the complex viewed from different angles; C, model of a dimer-only membrane, showing its tubular shape; D, model demonstrating that membranes comprising a mixture of dimers and LH2 complexes are spherical.

Selected Publications

Ratcliffe, E.C., Tunnicliffe R.B., Ng, I.W., Adams, P.G., Qian, P., Holden-Dye, K., Jones, M.R., Williamson, M.P. and Hunter, C.N. (2011) Experimental evidence that the membrane-spanning helix of PufX adopts a bent conformation that facilitates dimerisation of the Rhodobacter sphaeroides RC-LH1 complex through N-terminal interactions. Biochim. Biophys. Acta 1807, 95-107.

Şener, M.K., Strümpfer, J., Hsin, J., Chandler, D, Scheuring, S., Hunter, C.N. and Schulten, K. (2011) Förster energy transfer theory as reflected in the structures of photosynthetic light harvesting systems. ChemPhysChem 12, 518-531.

Adams, P.G., Mothersole, D.J., Ng, I.W., Olsen, J.D. and Hunter, C.N. (2011) Monomeric RC-LH1 core complexes retard LH2 assembly and intracytoplasmic membrane formation in PufX-minus mutants of Rhodobacter sphaeroides. Biochim. Biophys Acta 1807, 1044-1055.

Ng, I. W., Adams, P.G., Mothersole, D.J., Vasilev, C., Martin, E.C., Lang, H.P., Tucker, J.D. and Hunter, C.N. (2011) Carotenoids are essential for normal levels of dimerisation of the RC-LH1-PufX core complex of Rhodobacter sphaeroides: characterisation of R-26 as a crtB (phytoene synthase) mutant. Biochim. Biophys Acta 1807, 1056-1063.

Šlouf, V, Chábera, P., Olsen, J.D., Martin, E.C., Qian, P., Hunter, C.N. and Polívka, T. (2012) Photoprotection in a purple phototrophic bacterium mediated by oxygen-dependent alteration of carotenoid excited-state properties. Proc. Natl. Acad. Sci. USA 109, 8570-8575.

Freiberg, A. Kangur, L. Olsen, J.D. and Hunter, C.N. (2012) Structural implications of hydrogen bond energetics in membrane proteins revealed by high-pressure spectroscopy Biophys. J. 103, 2352-2360.

Adams, P.G., Cadby, A.J., Robinson, B., Tsukatani, Y., Tank, M., Wen, J., Blankenship, R.E., Bryant, D.A., and Hunter, C.N. (2013) Comparison of the physical characteristics of chlorosomes from three different phyla of green phototrophic bacteria. Biochim. Biophys. Acta Bioenergetics 1827, 1235-44.

Harris, M.A., Parkes-Loach, P.S., Springer, J.W., Jiang, J., Martin, E.C., Qian, P., Jiao, J., Niedzwiedzki, D.M., Kirmaier, C., Olsen, J.D., Bocian, D.F., Holten, D., Hunter, C.N., Lindsey, J.S., and Loach, P.A. (2013) Integration of multiple chromophores with native photosynthetic antennas to enhance solar energy capture and delivery. Chemical Science 4, 3924-3933.

Qian, P., Papiz, M.Z., Jackson, P.J., Brindley, A.A., Ng, I., Olsen, J.D., Dickman, M.J., Bullough, P.A. and Hunter, C.N. (2013) The 3-D structure of the Rhodobacter sphaeroides RC-LH1-PufX complex: dimerization and quinone channels promoted by PufX. Biochemistry 52, 7575-7585.

Vasilev, C., Brindley, A.A., Olsen, J.D., Saer, R.G., Beatty, J. T. and Hunter, C.N. (2014) Nano-mechanical mapping of interactions between surface-bound RC -LH1-PufX core complexes and cytochrome c2 attached to an AFM probe. Photosynthesis Research 120, 169-180.

Cartron, M.L., Olsen, J.D., Sener, M., Jackson, P.J., Brindley, A.A., Qian, P., Dickman, M.J., Leggett, G.J., Schulten, K. and Hunter, C.N. (2014) Integration of energy and electron transfer processes in the photosynthetic membrane of Rhodobacter sphaeroides. Biochim Biophys Acta Bioenergetics 1837 1769-1780

Timpmann, K., Chenchiliyan, M., Jalviste, E., Timney, J.A., Hunter, C.N. and Freiberg, A. (2014) Efficiency of light harvesting in photosynthetic bacteria adapted to different levels of light. Biochim Biophys Acta 1837, 1835-1846.

Chi, S.C., Mothersole, D.J., Dilbeck, P., Niedzwiedzki, D.M., Zhang, H., Qian, P., Vasilev, C., Grayson, K.J., Jackson, P.J., Martin E.C., Li, Y., Holten, D. and Hunter, C.N. (2015) Assembly of functional photosystem complexes in Rhodobacter sphaeroides incorporating carotenoids from the spirilloxanthin pathway. Biochim. Biophys. Acta. 1847(2) 189-201.

Horibe, T., Qian, P. Hunter, C.N. and Hashimoto, H. (2015) Stark absorption spectroscopy on the carotenoids bound to B800-820 and B800-850 type LH2 Complexes from a purple photosynthetic bacterium, Phaeospirillum molischianum strain DSM120. Arch. Biochem. Biophys. 572, 158-166.

Niedzwiedzki, D.M., Dilbeck, P.L., Tang, Q., Mothersole, D.J., Martin E.C., Li, Y., Bocian, D.F., Holten, D. and Hunter, C.N. (2015) Functional characteristics of spirilloxanthin and longer-chain keto-bearing analogues in light-harvesting LH2 complexes from Rhodobacter sphaeroides with a genetically modified carotenoid bioynthesis pathway. Biochim Biophys Acta 1847, 640-655.

Dilbeck, P.L., Tang, Q., Mothersole, D.J., Martin, E.C., Hunter, C.N., Bocian, D.F., Holten, D and Niedzwiedzki, D. M. (2016) Quenching capabilities of long-chain carotenoids in light-harvesting-2 complexes from Rhodobacter sphaeroides with engineered carotenoid synthesis pathways. J. Phys Chem B 120, 5429-5443.

Dahlberg, P.D., Ting, T-C., Massey, S.C., Martin, E.C., Hunter, C.N. and Engel, G.S. (2016) Electronic structure and dynamics of higher-lying excited states in light harvesting complex 1 from Rhodobacter sphaeroides. J. Phys Chem A 120, 4124-4130.


Assembly and organisation of photosynthetic membranes

Photosynthetic organisms increase the surface area for light absorption and photochemistry by elaborating internal membranes into lamellar, tubular or spherical structures. Membrane development establishes the architectures that harvest, transduce and store solar energy. We are using a combination of atomic force microscopy and molecular genetics to study the spatial organisation of the bacterial photosynthetic apparatus, and the strategies employed for efficient harvesting and trapping of solar energy by photosynthetic bacteria.

fig3

Figure 3: Left, cells of a photosynthetic bacterium. Middle, electron micrograph of a section through a cell of Rhodobacter sphaeroides. Right, atomic force microscopy of a photosynthetic membrane, showing individual photosynthetic complexes; single LH2 antenna complexes and RC-LH1-PufX dimers can be resolved.

Selected Publications

Jackson, P.J., Lewis, H.J., Tucker, J.D., Hunter, C.N. and Dickman, M.J. (2012) Quantitative proteomic analysis of intracytoplasmic membrane development in Rhodobacter sphaeroides. Mol. Microbiol. 84, 1062-1078.

Adams, P.G. and Hunter, C.N. (2012) Adaptation of intracytoplasmic membranes to altered light intensity in Rhodobacter sphaeroides. Biochim Biophys. Acta 1817, 1616–1627.

Chidgey, J.W., Linhartová, M. Komenda, J., Jackson, P.J., Dickman, M.J., Canniffe, D.P., Koník, P., Pilný, J., Hunter, C.N., and Sobotka, R. (2014) A cyanobacterial chlorophyll synthase-HliD-Ycf39-YidC complex links chlorophyll and protein biosynthesis. Plant Cell 26 (3) 1267-1279.

Johnson, M.P., Vasilev, C., Olsen, J.D., and Hunter, C.N., (2014) Nanodomains of cytochrome b6f and photosystem II complexes in plant photosynthetic membranes. Plant Cell 26, 3051-61.

Olsen, J.D., Adams, P.G. and Hunter, C.N. (2014) Aberrant assembly intermediates of the RC-LH1-PufX core complex of Rhodobacter sphaeroides imaged by atomic force microscopy. J. Biol. Chem 289(43), 29927-29936.

Sener, M., Stone, J.E., Barragan, A., Singharoy, A., Teo, I., Vandivort, K.L., Isralewitz, B., Liu, B., Goh, B.C., Phillips, J.C., Kourkoutis, L.F., Hunter, C.N. and Schulten, K. (2014) Visualization of energy conversion processes in a light harvesting organelle at atomic detail. In: Proceedings of the International Conference on High Performance Computing, Networking, Storage and Analysis, SC ’14. IEEE Press.

Benson, S.L., Maheswaran, P., Ware, M.A., Hunter, C.N., Horton, P., Jansson, S., Ruban, A.V. and Johnson, M.P. (2015) An intact light harvesting complex I antenna system is required for complete state transitions in Arabidopsis. Nature Plants 1, article number 15176

Majumder, E. L-W., Olsen, J.D., Qian, P., Collins, A.M., Hunter, C.N. and Blankenship, R.E. (2016) Supramolecular organization of photosynthetic complexes in membranes of Roseiflexus castenholzii. Photosynth. Res. 127(1):117-130.

Mothersole, D.J. Jackson, P.J., Vasilev, C., Tucker, J.D., Brindley, A.A., Dickman, M.J. and Hunter, C.N. (2016) PucC and LhaA direct efficient assembly of the light-harvesting complexes in Rhodobacter sphaeroides. Molecular Microbiology. 99(2), 307-327.

Hollingshead, S., Kopečná, J., Armstrong, D.R., Bučinská, L., Jackson, P.J., Chen, G.E., Dickman, M.J., Williamson, M.P., Sobotka, R. and Hunter, C.N. (2016) Synthesis of chlorophyll-binding proteins in a fully-segregated ∆ycf54 strain of the cyanobacterium Synechocystis PCC 6803. Frontiers in Plant Sciences 7, 1-15.

Stone, J.E., Sener, M., Vandivort, K.L., Barragan, A., Singharoy, A., Teo, I., Ribeiro, J.V., Isralewitz, B., Liu, B., Goh, B.C., Phillips, J.C., MacGregor-Chatwin, C., Johnson, M.P., Kourkoutis, L.F., Hunter, C.N. and Schulten, K. (2016) Atomic detail visualization of photosynthetic membranes with GPU-accelerated ray tracing, Parallel Computing, 55, 17-27.

Chenchiliyan, M., Timpmann, K., Jalviste, E., Adams, P.G., Hunter, C.N., and Freiberg, A. (2016) Dimerization of core complexes as an efficient strategy for light harvesting in Rhodobacter sphaeroides. Biochim. Biophys Acta Bioenergetics 1857, 634-642


Bionanotechnology of light harvesting complexes.

Atomic-level structural models of whole membrane assemblies have now been constructed by Klaus Schulten and Melih Sener at the Beckman Institute, Illinois, USA, using a combination of crystallographic, AFM and electron microscopy data allied to computational modeling. Such models are starting to address the collective behaviour of whole membrane assemblies, to make predictions of the energy transfer and trapping behaviour of large-scale arrays, and to identify desirable design motifs for artificial photosynthetic systems. New surface chemistries and nanopatterning methods are being developed in collaboration with Professor Graham Leggett (Sheffield) and Dr Cees Otto (University of Twente, the Netherlands) to facilitate the construction of innovative architectures for coupled energy transfer and trapping. Nanometre-scale patterns of photosynthetic complexes have been fabricated on self-assembled monolayers deposited on either gold or glass using several lithographic methods. Such artificial light-harvesting arrays will advance our understanding of natural energy-converting systems, and could guide the design and production of proof-of-principle devices for biomimetic systems to capture, convert and store solar energy.

fig4

Figure 4: Left, atomic-level structural model of a complete photosynthetic membrane showing LH2 complexes (green) and RC-LH1-PufX dimers (red/blue). Right, diagram showing nanopatterning of LH2 complexes on a gold surface to form a new, artificial energy transfer array.

Selected Publications

Magis, J. G., Olsen, J.D., Reynolds, N.P., Leggett, G.J., Hunter, C.N., Aartsma, T.J., Frese, R.N. (2011) Use of engineered unique cysteine residues to facilitate oriented coupling of proteins directly to a gold substrate. Photochem. Photobiol. 87, 1050-57.

ul Haq, E., Patole, S., Moxey, M., Amstad, E., Vasilev, C., Hunter, C.N., Leggett, G.J., Spencer, N.D., and Williams, N.H. (2013) Photocatalytic Nanolithography of SAMs and Proteins. ACS Nano 7, 7610-7618.

Vasilev, C., Johnson, M. P., Gonzales, E., Wang, L., Ruban, A. V., Cadby, A.J., Montano, G. and Hunter, C. N. (2014) Reversible switching between nonquenched and quenched states in nanoscale linear arrays of plant light harvesting antenna complexes. Langmuir 30 (28) 8481-8490.

Tsargorodska, A. El Zubir, O., Darroch, B., Cartron, M.L., Basova, T., Hunter, C. N., Nabok, A. and Leggett, G.L. (2014) Fast, simple, combinatorial routes to the fabrication of reusable, plasmonically active gold nanostructures by interferometric lithography of self-assembled monolayers. ACS Nano 8, 7858-7869.

Patole, S, Vasilev, C, El-Zubir, O., Wang, L., Johnson, M.P., Cadby, A.J., Leggett, G.J and Hunter, C.N. (2015) Interference lithographic nanopatterning of light-harvesting complexes on gold and mica substrates. Interface Focus 5(4), 2015005.

Moxey, M.A., Johnson, A., El-Zubir, O., Cartron, M.L., Dinachali, S.S., Hunter, C.N., Saifullah, M.S.M., Chong, K.S. and Leggett, G.J. (2015) Self-cleaning, re-useable titania templates for nanometer and micrometer scale protein patterning ACS Nano 9(6) 6262-6270.

Mostegel, F., Ducker, R.E., Rieger, P.H., El-Zubir, O., Xia, S. Radl, S.V., Edler, M., Cartron, M.L., Hunter, C.N., Leggett, G.J., Griesser, T. (2015) Versatile thiol-based reactions for micrometer- and nanometer-scale photopatterning of polymers and biomolecules. J. Mat. Chem. B 3(21) 4431-4438.

Xia, S. Cartron, M.L., Morby, J., Bryant, D.A., Hunter, C.N. and Leggett, G.J. (2016) Fabrication of nanometer and micrometer scale protein structures by site-specific immobilization of Histidine-tagged proteins to aminosiloxane films with photoremovable protein-resistant protecting groups. Langmuir 32(7), 1818-1827.

Teaching

Level 3 Modules

PhD Opportunities

I welcome applications from prospective home / EU PhD students for two fully funded PhD studentships: see details below.

You can apply for a PhD position in MBB here.

Contact me at c.n.hunter@sheffield.ac.uk for further information.


Structural role of photosystem II supercomplexes in thylakoid membrane stacking - FULLY FUNDED

Life on earth depends on photosynthesis, the source of all of our food, oxygen and most of our energy. The early steps of photosynthesis involve trapping of solar energy by electron transfer reactions in the photosynthetic membrane. Our recent studies have revealed an unexpected role for the membrane protein photosystem II (PSII) supercomplexes in mediating the stacking of chloroplast thylakoid membranes. Membrane stacking instigates the spatial segregation of the slow excitation energy trap PSII from the faster trap photosystem I (PSI), and promotes energy transfer among PSII units both of which are crucial for the efficiency of photosynthesis. For the first time we have biochemically-isolated a unique stacked form of the PSII supercomplex which will allow us to investigate this critical feature of the process. This project will make use of the latest advances in structural and functional microscopies to characterise this PSII supercomplex and understand how and why thylakoid membranes stack in molecular detail.

The PhD will offer the candidate a broad interdisciplinary training in modern biochemistry purification techniques, mass spectrometry and fluorescence and absorption spectroscopy, with the opportunity to interact with biologists, biophysicists and chemical engineers during the course of their project.

Relevant publications:

Ruban AV, Johnson MP (2015) Towards visualization of the dynamics of the plant photosynthetic membrane. Nature Plants. In Press.

Johnson MP, Vasilev C, Olsen J, Hunter CN (2014) Nanodomains of cytochrome b6f and photsosytem II in spinach grana thylakoid membranes. Plant Cell. 26, 3051-3061

This studentship is funnded by the BBSRC White Rose DTP.

Pushing electrons: How does nature make it work in natural two-dimensional solar cells? - FULLY FUNDED

The aim of the project is to characterise the molecular interactions at the single molecule level that govern the transient interface between the electron donor plastocyanin and photosystem I or cytochrome b6f, during photosynthesis in plants, algae and cyanobacteria. Specifically the project will investigate the timescales of the protein conformational changes and electron transfer reactions involved and their environmental dependence using nanoelectrical and nanomechanical atomic force microscopy and further characterize the exact molecular interactions via cross-linking and mass spectrometry.

Electron transfer reactions are the basis of photosynthesis and respiration, which power all life on Earth. In essence energy directly provided by the sun or from foodstuffs is used to move electrons along a chain of proteins; some of these proteins can move freely, shuttling back and forth carrying their cargo of electrons to and from other proteins that are held in position within a thin sheet of membrane. The mystery is how a freely-moving protein finds its way to a particular membrane-attached protein, how it docks at the membrane surface, releases its electron and then manages to undock, all in a few milliseconds. Yet without hundreds of these electron transfer reactions happening every second, life on Earth could not be sustained. Somehow these pairs of proteins balance two conflicting requirements: they have to come together quickly and specifically to transfer electrons, yet they also have to be able to separate rapidly afterwards. So whatever forces brought the proteins together in the first place can be switched into reverse – how is this possible? What is this switch? Finding this out is the purpose of the proposed research, and it has important implications for all energy-yielding electron transfers on Earth.

This four-year studentship will be fully funded at Home/EU or international rates. Support for travel and consumables (RTSG) will also be made available at standard rate of £2,627 per annum, with an additional one-off allowance of £1,000 for a computer in the first year. Students will receive an annual stipend of £17,336. The stsudent will be part of the Grantham Centre for Sustainable Futures.

Applying: Apply online here. Please select ‘standard PhD’ not DTC option, and ‘Department of Molecular Biology and Biotechnology’. Your application for this studentship should be accompanied by a CV and a 200 word supporting statement. Your statement should outline your aspirations and motivation for studying in the Grantham Centre, outlining any relevant experience. Deadline for application is Feb 23 2017.









































Complete Publication List

Journal articles

Conference proceedings papers

  • Adams PG, Vasilev C, Collins AM, Montano GA, Hunter CN & Johnson MP (2016) Redesigning Photosynthetic Membranes: Development of Bio-Inspired Photonic Nanomaterials. BIOPHYSICAL JOURNAL, Vol. 110(3) (pp 19A-19A)
  • Leggett GJ, Alswieleh A, Cheng N, Canton I, Ustbas B, Xue X, Ladmiral V, Xia S, Ducker RE, El Zubir O, Cartron ML, Hunter CN & Armes SP (2014) Synthesis and nanometer-scale patterning of stimulus-responsive, biofouling-resistant zwitterionic poly(amino acid methacrylate) brushes. ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY, Vol. 248
  • Ducker RE, El Zubir O, Wang L, Cartron ML, Mullin N, Cadby A, Hobbs J, Hunter CN & Leggett GJ (2014) Nanoscale positioning of multiple proteins by scanning near-field photolithography. ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY, Vol. 248
  • Harris MA, Springer JW, Parkes-Loach PS, Reddy KR, Krayer M, Jiao J, Niedzwiedzki DM, Pavan P, Martin E, Olsen JD, Hunter CN, Kirmaier C, Holten D, Bocian DF, Lindsey JS & Loach PA (2013) Biohybrid antenna complexes with native peptide analogs and tunable synthetic chromophores. ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY, Vol. 245
  • Kodali G, Farid TA, Solomon LA, Lichtenstein BR, Anderson JLR, Mass OA, Esipova TV, Patole S, Sheehan MM, Ennist NM, Fry BA, Bialas CP, Mancini JA, Zhao Z, Vinogradov SA, Hunter CN, Lindsey JS, Discher BM, Moser CC & Dutton PL (2012) Single designed protein platform with multiple functionalities: Oxidoreductase, oxygen transport, light-harvesting, and light activated electron transfer. ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY, Vol. 244
  • Magis JG, Frese RN, Olsen JD, Hunter CN & Aartsma TJ (2007) Enhanced stability of photosynthetic energy transfer proteins on gold surfaces.. BIOPHYSICAL JOURNAL (pp 507A-507A)
  • Ratsep M, Hunter CN, Olsen JD & Freiberg A (2005) Band structure and local dynamics of excitons in bacterial light-harvesting complexes revealed by spectrally selective spectroscopy. PHOTOSYNTHESIS RESEARCH, Vol. 86(1-2) (pp 37-48)
  • Bullough PA, Jamieson SJ, Walz T, Hunter CN, Bowers CM, Karrasch S, Ghosh R, Henderson R & Subramaniam S (1999) Energy production in biological systems probed by electron crystallography. ELECTRON MICROSCOPY AND ANALYSIS 1999(161) (pp 127-132)
  • FOWLER GJS, CRIELAARD W, VISSCHERS RW, VANGRONDELLE R & HUNTER CN (1993) SITE-DIRECTED MUTAGENESIS OF THE LH2 LIGHT-HARVESTING COMPLEX OF RHODOBACTER-SPHAEROIDES - CHANGING BETA-LYS23 TO GLN RESULTS IN A SHIFT IN THE 850 NM ABSORPTION PEAK. PHOTOCHEMISTRY AND PHOTOBIOLOGY, Vol. 57(1) (pp 2-5)