Kevin Giles

Publications (35) View all

• Article: The kinetic ion mobility mass spectrometer: measurements of ion-molecule reaction rate constants at atmospheric pressure

  K. Giles, E. P. Grimsrud
  04/2002;
• Article: Measurements of equilibria and reactivity of cluster ions at atmospheric pressure: reactions of Cl-(CHCl3)0-2 with methyl bromide and methyl iodide

  K. Giles, E. P. Grimsrud
  04/2002;
• Source

  Available from: Kiran Chintakayala

  Article: Insights into the structure and assembly of the Bacillus subtilis clamp-loader complex and its interaction with the replicative helicase

  José P. Afonso, Kiran Chintakayala, Chatrudee Suwannachart, Svetlana Sedelnikova, Kevin Giles, John B. Hoyes, Panos Soultanas, John B. Rafferty, Neil J. Oldham
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  ABSTRACT: The clamp-loader complex plays a crucial role in DNA replication by loading the β-clamp onto primed DNA to be used by the replicative polymerase. Relatively little is known about the stoichiometry, structure and assembly pathway of this complex, and how it interacts with the replicative helicase, in Gram-positive organisms. Analysis of full and partial complexes by mass spectrometry revealed that a hetero-pentameric τ3-δ-δ′ Bacillus subtilis clamp-loader assembles via multiple pathways, which differ from those exhibited by the Gram-negative model Escherichia coli. Based on this information, a homology model of the B. subtilis τ3-δ-δ′ complex was constructed, which revealed the spatial positioning of the full C-terminal τ domain. The structure of the δ subunit was determined by X-ray crystallography and shown to differ from that of E. coli in the nature of the amino acids comprising the τ and δ′ binding regions. Most notably, the τ-δ interaction appears to be hydrophilic in nature compar
  Nucleic Acids Research 01/2013; · 8.03 Impact Factor
• Article: QconCAT Standard for Calibration of Ion Mobility-Mass Spectrometry Systems.

  Ross Chawner, Bryan McCullough, Kevin Giles, Perdita E Barran, Simon J Gaskell, Claire E Eyers
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  ABSTRACT: Ion mobility-mass spectrometry (IM-MS) is a useful technique for determining information about analyte ion conformation in addition to mass/charge ratio. The physical principles that govern the mobility of an ion through a gas in the presence of a uniform electric field are well understood, enabling rotationally averaged collision cross sections (Ω) to be directly calculated from measured drift times under well-defined experimental conditions. However, such "first principle" calculations are not straightforward for Traveling Wave (T-Wave) mobility separations due to the range of factors that influence ion motion through the mobility cell. If collision cross section information is required from T-Wave mobility separations, then calibration of the instruments using known standards is essential for each set of experimental conditions. To facilitate such calibration, we have designed and generated an artificial protein based on the QconCAT technology, QCAL-IM, which upon proteolysis can be used as a universal ion mobility calibration standard. This single unique standard enables empirical calculation of peptide ion collision cross sections from the drift time on a T-Wave mobility instrument.
  Journal of Proteome Research 09/2012; · 5.11 Impact Factor
• Article: Isomer separation and gas-phase configurations of organoruthenium anticancer complexes: ion mobility mass spectrometry and modeling.

  Jonathan P Williams, Tijana Bugarcic, Abraha Habtemariam, Kevin Giles, Iain Campuzano, P Mark Rodger, Peter J Sadler
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  ABSTRACT: We have used ion mobility-mass spectrometry combined with molecular modeling for the separation and configurational analysis of three low-molecular-weight isomeric organoruthenium anticancer complexes containing ortho-, meta-, or para-terphenyl arene ligands. The isomers were separated using ion mobility based on traveling-wave technology and the experimentally determined collision cross sections were compared to theoretical calculations. Excellent agreement was observed between the experimentally and theoretically derived measurements.
  Journal of the American Society for Mass Spectrometry 03/2009; 20(6):1119-22. · 4.00 Impact Factor