Research Guides

Mechanistic studies of structure and function by EPR Spectroscopy

Work in the Centre for Advanced Electron Spin Resonance, CÆSR, involves collaborations on bridged metal clusters, biophysical distance measurements, transient organic radicals, electron transfer processes, and electron paramagnetic resonance (EPR) instrumentation and methods development.  My role in the department is to serve as the Scientific Applications Manager of CAESR.  As an academic, I am involved with research collaborations, co-supervision of Part II, D. Phil and PDRA research, authorship of grants and publications and serving as a reviewer for ACS, AIP, IOP, and Springer journals.  I am also responsible for facility management of the ESR Centre. 

My own research is generally on the biophysical applications of EPR, with a focus on bioinorganic systems, and I have worked on iron-sulfur proteins with the Fraser Armstrong and Kylie Vincent groups.  Bioinorganic studies often involve novel biomimetic metal complexes and this has led to related projects on transition metal complexes that are decidedly non-biological.  High-spin Co(II) and other complexes with unquenched orbital momentum have been an ongoing interest, both as a surrogate of the ubiquitous Zn(II) metalloenzymes and on the side of basic studies in transition metal magnetic properties,  electronic structure, and coordination chemistry. 

Figures. Left to right are rapid-passage Q-band CW-ENDOR of bistrispyrazolylboratecobalt(II) measured at 1.6 Kelvin, an electron spin echo field sweep at D-band of the first photo-excited state (S2) of photosystem II, and a finite integral method calculation of the microwave magnetic field amplitude in a transverse electric mode (011) Ka-band ENDOR resonator.

Current funding: UCB Celltech (CÆSR), Chemistry Dept., Bruker-BioSpin (CÆSR), SAB Miller (C. Timmel), ERC CoSuN (H. Anderson), and EPSRC (CÆSR)

I studied Chemistry at Carleton College in the class of 2002 and this involved 15 months research under Dr. Mary P. Neu at Los Alamos National Laboratory, where I worked on Pu(IV) separations with transferrin and biogeochemical interactions of Pu(VI) and U(VI) with synthetic and biogenic MnO2.  My Ph.D. in Inorganic Chemistry was from the University of New Mexico in 2008, with Prof. David L. Tierney, involving CW-EPR, CW-ENDOR, paramagnetic NMR, and EXAFS of high-spin Co(II) model complexes and substituted Zn(II) enzymes.  Following a PDRA with Prof. Charles P. Scholes of University at Albany, where the first measurements of 17O hyperfine couplings in the Oxygen Evolving Complex of Photosystem II were published and Double Electron-Electron Resonance (DEER) applied to Zinc-Finger / DNA interactions of HIV, I was a PDRA in the laboratory of Prof. R. David Britt of UC Davis from 2010 to mid-2013.  Of many projects with Prof. Britt, such as radical SAM iron-sulfur proteins and nitrogenase, the most notable was discovery of mechanistic aspects of biogenesis of the [FeFe]-Hydrogenase catalytic H-cluster and improvements to the EPR centre's multi-frequency DEER capabilities, leading to measurements that support a new mechanistic understanding of the circadian clock proteins in cyanobacteria.

“Ribonucleotide Reductase Requires Subunit Switching in Hypoxia to Maintain DNA Replication”,  Iosifina P. Foskolou, Christian Jorgensen, Katarzyna B. Leszczynska, Monica M. Olcina, Hanna Tarhonskaya, Bauke Haisma, Vincenzo D’Angiolella, William K. Myers, Carmen Domene, Emily Flashman, Ester M. Hammond, Molecular Cell, 2017, 66, 1–15, DOI: 10.1016/j.molcel.2017.03.005.

“Selective Catalytic Reduction of N2 to N2H4 by a Simple Fe Complex”. Peter J Hill, Laurence R. Doyle, Andrew D. Crawford, William K. Myers, and Andrew E. Ashley, J. Am. Chem. Soc., 2016, DOI: 10.1021/jacs.6b08802.

“N-heterocyclic carbene induced reductive coupling of phosphorus tribromide. Isolation of a bromine bridged P–P bond and its subsequent reactivity”. Jordan Waters, Thomas Everitt, William Myers and Jose M. Goicoechea, Chem. Sci., 2016, DOI: 10.1039/C6SC02343F.

“The Original CoII Heteroscorpionates Revisited: On the EPR of Pseudotetrahedral CoII”. Robert R Baum, William K Myers, Samuel M Greer, Robert M Breece, David L Tierney, Eur. J. Inorg. Chem. 2016, DOI: 10.1002/ejic.201501356.

“Synthesis, Structure, and Bonding for Bis(permethylpentalene)diiron”. Samantha C. Binding, Jennifer C. Green, William K. Myers, and Dermot O’Hare, Inorg. Chem., 2015, 54 (24), pp 11935–11940. DOI: 10.1021/acs.inorgchem.5b02254

“Discovery of Dark pH-Dependent H+ Migration in a [NiFe]-Hydrogenase and Its Mechanistic Relevance: Mobilizing the Hydrido Ligand of the Ni-C Intermediate”. Bonnie J. Murphy, Ricardo Hidalgo, Maxie M. Roessler, Rhiannon M. Evans, Philip A. Ash, William K. Myers, Kylie A. Vincent, and Fraser A. Armstrong, J. Am. Chem. Soc. 2015, 137 (26), 8484–8489.

“A Protein Fold Switch Joins the Circadian Oscillator to Clock Output in Cyanobacteria”. Yong-Gang Chang, Susan E. Cohen, Connie Phong, William K. Myers, Yong-Ick Kim, Roger Tseng, Jenny Lin, Li Zhang, Joseph S. Boyd, Yvonne Lee, Shannon Kang, Sheng Li, R. David Britt, Michael J. Rust, Susan S. Golden, Andy LiWang, Science 2015, 349 (6245), 324-328.

“How Formaldehyde Inhibits Hydrogen Evolution by [FeFe]-Hydrogenases: Determination by 13C ENDOR of Direct Fe–C Coordination and Order of Electron and Proton Transfers”. Andreas Bachmeier, Julian Esselborn, Suzannah V. Hexter, Tobias Krämer, Kathrin Klein, Thomas Happe, John E. McGrady, William K. Myers , and Fraser A. Armstrong, J. Am. Chem. Soc. 2015, 137 (16), 5381–5389.

“Pulse Dipolar ESR of Doubly Labeled Mini TAR DNA and Its Annealing to Mini TAR RNA”. Yan Sun, Peter P. Borbat, Vladimir M. Grigoryants, William K. Myers, Jack H. Freed, Charles P. Scholes, Biophysical Journal 2015, 108 (4), 893–902.

“The Cyanide Ligands of [FeFe] Hydrogenase: Pulse EPR Studies of 13C and 15N-Labeled H-Cluster”. William K. Myers, Troy Stich, Daniel L. M. Suess, Jon M. Kuchenreuther, James R. Swartz, R. David Britt, J. Am. Chem. Soc. 2014, 136 (35), 12237–12240.

“Paramagnetic Intermediates Generated by Radical SAM Enzymes”. Troy Stich, William K. Myers, R. David Britt, Acc. Chem. Res. 2014, 47 (8), 2235–2243.

“Synthesis and characterization of [Ru@Ge12]3–: an endohedral 3-connected cluster”. Gabriela Espinoza-Quintero, Jack C. A. Duckworth, William K. Myers, John E. McGrady, and Jose Manuel Goicoechea, J. Am. Chem. Soc. 2014, 136 (4), 1210–1213.

“The HydG Enzyme Generates an Fe(CO)2(CN) Synthon in the Biosynthesis of [FeFe] Hydrogenase”. Jon M. Kuchenreuther†, William K. Myers†, Daniel L. M. Suess, Troy A. Stich, Vladimir Pelmenschikov, Stacey A. Shiigi, Stephen P. Cramer, James R. Swartz, R. David Britt, Simon J. George, Science 2014, 343, 424-427.

“Radical Intermediate in Tyrosine Scission to the CO and CN− Ligands of [FeFe] Hydrogenase”.  Jon M. Kuchenreuther^†, William K. Myers^†, Troy A. Stich, Simon J. George, Yaser NejatyJahromy, James R. Swartz, and R. David Britt, Science 2013, 342, 472-475.

“The conformation of P450cam in complex with putidaredoxin is dependent on oxidation state”. William K. Myers, Young-Tae Lee, R. David Britt, and David B. Goodin, J. Am. Chem. Soc. 2013, 135, 11732–11735.

“9-Mercaptodethiobiotin is Generated as a Ligand to the [2Fe-2S]⁺ Cluster During the Reaction Catalyzed by Biotin Synthase from Escherichia coli”. Corey J. Fugate, Troy A. Stich, Esther G. Kim, William K. Myers, R. David Britt, Joesph T. Jarrett, J. Am. Chem. Soc. 2013, 134, 9042–9045.

“The Internal Dynamics of Mini c TAR DNA Probed by Electron Paramagnetic Resonance of Nitroxide Spin-Labels at the Lower Stem, the Loop, and the Bulge”. Yan Sun, Ziwei Zhang, Vladimir M. Grigoryants, William K. Myers, Fei Liu, Keith A. Earle, Jack H. Freed, and Charles P. Scholes, Biochemistry 2012, 51 (43), 8530–8541.

“EPR–ENDOR Characterization of (17O, 1H, 2H) Water in Manganese Catalase and Its Relevance to the Oxygen-Evolving Complex of Photosystem II”. Iain L. McConnell, Vladimir M. Grigoryants, Charles P. Scholes, William K. Myers, Ping-Yu Chen, James W. Whittaker, and Gary W. Brudvig, J. Am. Chem. Soc. 2012, 134 (3), 1504–1512