An urgent problem in protein science is to understand ion uptake and ion recognition (selectivity) by proteins and polypeptides. This impacts proteins ranging from ion channels to ion sensors to metalloregulatory proteins to metallo-enzymes. Why and how are these bio-nanostructures so exquisitely sensitive to particular ions? How do local changes in the binding pockets lead to global conformational change? These questions have major implications for biology, and they need an answer from physical chemistry. In a separate field, that of green chemistry, there is another pressing problem to understand structural and dynamical heterogeneity in ionic liquids. What does this proposed heterogeneity imply about the solvation properties of these new "designer solvents''? Can we measure it? Can we use it to tune the solvent's properties? Better understanding the chemical physics of these systems will aid the rational design of new solvents, which in turn will have industrial consequences. There is an underlying connection between these biophysical and chemical physics questions – to really probe the mechanisms in operation, one must be able to separate static and dynamic heterogeneity. The nonliear spectroscopies developed in the Garrett-Roe lab can do exactly this. Multidimensional infrared spectroscopy can reveal structural dynamics on timescales spanning femtosecond–microseconds, and make molecular movies as reported by vibrational frequencies. These techniques will clarify
- The mechanism of ion selectivity in selectivity filter of an archetypal biological ion channel (KcsA).
- The conformational dance of guest and host in the molecular recognition of ionophores such as valinomycin.
- The binding of calcium ions in a biological ion sensor, EF hand, in a time- and reside-resolved way. Calcium uptake is a key step of many cellular signalling processes and is unexplored on a submicrosecond timescale.
- The structural and dynamical heterogeneity of ionic liquids. These fluids are a fascinating arena to move towards a deeper understanding of complex fluids.
Each of these experiments requires a combination of experimental expertise in the non-linear spectroscopy as well as skill modelling stochastic dynamics on a complex free energy landscape.
|Mitra, Sunayana||Graduate Studentfirstname.lastname@example.org|
|Brinzer, Thomas||Graduate Studentemail@example.com|
|Johnson, Clinton||Graduate Studentfirstname.lastname@example.org|
|Ren, Zhe||Graduate Studentemail@example.com|
|Dutta, Samrat||Postdoctoral Fellowfirstname.lastname@example.org|
|Coate, Emma||Undergraduate Studentemail@example.com|
|Kelly, Jordan||Undergraduate Student|
|Wagner, Molly||Undergraduate Student|
- "Time- and angle-resolved two-photon photoemission studies of electron localization and solvation at interfaces," P. Szymanski1, S. Garrett-Roe, C.B. Harris, Progress in Surface Science 78, 1 (2005)
- "Electron Solvation in Two Dimensions," A. D. Miller, I. Bezel, K. J. Gaffney, S. Garrett-Roe, S. H. Liu, P. Szymanski, C. B. Harris, Science 297, 1163 (2002)
- "Intermolecular zero-quantum coherence imaging of the human brain," Rahim R. Rizi, Sangdoo Ahn, David C. Alsop, Sean Garrett-Roe, Marlene Mescher, Wolfgang Richter, Mitchell D. Schnall, John S. Leigh, Warren S. Warren, Magnetic Resonance in Medicine 43, 627 (2000)
- "Transient excitons at metal sufaces," Cui, X., Wang, C., Argondizzo, A., Garrett-Roe, S., Gumhalter, B., Petek, H., Nature Physics 10, no. 7 (2014)
- "Purely absorptive three-dimensional infrared spectroscopy," Sean Garrett-Roe and Peter Hamm, J. Chem. Phys. 130, 164510 (2009)
- "An Ultrafast Vibrational Study of Dynamical Heterogeneity in the Protic Ionic Liquid Ethyl-ammonium Nitrate," Johnson, Clinton, Anthony W. Parker, Paul M. Donaldson, and Sean Garrett-Roe. ChemRxiv (2019).
- "Viscosity Dependence of the Ultrafast Vibrational Dynamics of Borohydride in NaOH Solutions: Crowding Effect on Dihydrogen Bonds," Johnson, Clinton, Kai C. Gronborg, Thomas Brinzer, Zhe Ren, and Sean Garrett-Roe. ChemRxiv (2019).
- "Modeling Carbon Dioxide Vibrational Frequencies in Ionic Liquids: III. Dynamics and Spectroscopy," Thomas Brinzer, Clyde A. Daly, Cecelia Allison, Sean Garrett-Roe, and Steven A. Corcelli, J. Phys. Chem. B (2018)
- "Hydrogen bond dynamics in protic ionic liquids: Ultrafast vibrational spectroscopy of SCN." Garrett-Roe, Sean. In ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY, vol. 255. 1155 16TH ST, NW, WASHINGTON, DC 20036 USA: AMER CHEMICAL SOC, (2018).
- "POGIL activity clearinghouse: Helping authors to create, test, and distribute peer-reviewed POGIL activities." Garrett-Roe, Sean, Caryl Fish, Michael Garoutte, Melissa Reeves, Craig Teague, Robert Whitnell, Alexander Grushow, and Sally Hunnicutt. In ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY, vol. 255. 1155 16TH ST, NW, WASHINGTON, DC 20036 USA: AMER CHEMICAL SOC, (2018).