Department of Chemsitry

Dr L.C. Snoek

Physical & Theoretical Chemistry

lavina.snoek@chem.ox.ac.uk

Telephone: 44 (0) 1865 275 469/447

Research

The last few years have seen a very rapid growth of structural studies of biomolecules isolated in the gas-phase. The structures of neutral and partially hydrated systems including neurotransmitters, amides, nucleic acid bases and amino acids have been determined principally though laser-based vibrational spectroscopic methods in combination with high-level ab-initio calculations. Hydration studies are particularly important because, in addition to their intrinsic interest, they provide a link between the gas phase and the solution phase. Studies of secondary structure formation in dehydrated (and partially hydrated) peptides for example, will provide insight into the intramolecular (and solvent) interactions that stabilise helices and sheets. Under physiological conditions, important molecular groups are generally charged: basic groups can be protonated, acidic groups can be deprotonated, amino acids in neutral solution are predominantly zwitterions, peptides and proteins can be highly charged. Mass-spectrometric studies based on electrospray ionisation (ESI) observe multiply protonated, charged ions, [M+nH]n+, resulting from the addition of protons to basic sites of the biological sample. Therefore using a combination of MS techniques and laser spectroscopic techniques allows the structural investigation of molecular ions. These experiments currently take place in collaboration with the Free Electron Laser Facility FELIX in The Netherlands, where a FTICR spectrometer is interfaced with the IR radiation in the fingerprint and Amide regions. Current studies are focussing on the (mis)folding behaviour of amyloid peptide sequences which are believed to be important in diseases such as Alzheimer's Disease, Parkinson's and diabetes.

Selected Publications

1.     Infrared spectroscopy of ‘forbidden’ peptide sequences, Timothy D. Vaden, Sally A. N. Gowers and Lavina C. Snoek, Phys. Chem. Chem. Phys., 2009, 11, 5843.

2.     Vibrational Spectra of Small Protonated Peptides from Finite Temperature MD Simulations and IRMPD Spectroscopy, Cimas, A, Vaden, TD, de Boer, TSJA, Snoek, LC, Gaigeot, MP, Journal of Chemical Theory and Computation, 5 (4): 1068-1078, 2009.

3.     Observation of beta-Sheet Aggregation in a Gas-Phase Tau-Peptide Dimer, Vaden, T.D.,  Gowers, S.A.N.,  Snoek, L.C., J. Am. Chem. Soc., 131 (7): 2472-2474 FEB 25 2009.

4.     Conformational Preferences of an Amyloidogenic Peptide: IR Spectroscopy of Ac-VQIVYK-NHMe, Timothy D. Vaden, Sally A. N. Gowers, Tjalling S. J. A. de Boer, Jeffrey D. Steill, Jos Oomens and Lavina C. Snoek, J. Am. Chem. Soc., 2008, 130 (44), 14640–14650.


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