Carbohydrates, ion mobility, mass spectrometry
Ion mobility, carbohydrates, viral glycoproteins, lipids, mass spectrometry,negative ions
Research interests are the development and use of methods for the analysis of biological molecules by mass spectrometry. Early work involved methods for structural determination of steroids and the interpretation of the spectra of the trimethylsilyl (TMS) derivatives necessary to make them volatile for the technique. Work with anticonvulsant drugs in a study of placental transfer identified potentially toxic epoxides as metabolites. Studies by GC/MS on cannabinoids from marijuana resulted in the discovery of several new naturally-occurring compounds and the identification of several hundred metabolites, including epoxides, from many cannabinoids in eight species. High lipid solubility and long half-lives were confirmed and highlighted one of the main problems, namely accumulation in the body and production of the persistent cognitive impairment associated with this drug. New derivatization techniques were developed for long-chain fatty acids, alcohols and aldehydes allowing structural features such as double bond position, methyl branching and cyclopropane ring positions to be established in a single experiment, again by GC/MS. Applications were to meibomian lipids from the eye (associated with conditions such as dry eye) and secretions from skin.
Current work involves similar studies with carbohydrates with the main emphasis on the structure of N-linked glycans. These complex carbohydrates are attached to asparagine residues of proteins and are responsible for various functions such as cell-cell recognition, protein folding and pharmacokinetics. Studies are being made on the use of these compounds as disease biomarkers, particularly for cancer and for their use in vaccine development for viral diseases, particularly the newly emerging ones, for which no treatment currently exists. Recent applications have been to viruses such as Ebola, SARS and particularly HIV. The HIV gp120 envelope glycoprotein is one of the most highly glycosylated glycoproteins known and we have developed new methods for releasing the glycans prior to mass spectrometric analysis and methods based on negative ion fragmentation and ion mobility mass spectrometry for their structural analysis. Unlike the more common positive ion methods, this ion mobility/negative ion fragmentation method requires the minimum of sample preparation and provides more detailed structural information than the more laborious positive ion methods. The ion mobility step provides excellent gas-phase sample clean-up and a physical parameter, the collisional cross section to aid identification. One of the current projects aims at improving methods for cross section measurement on several instrument types. Also of interest is the structure of N-glycans in different, particularly non-mammalian species. The structure of these compounds can differ considerably depending on their source and are of interest not only medicinally for aspects such as drug development (e.g. for parasitic worms) and tissue transplants (avoiding rejection) but in improving our understanding of the mass spectrometric fragmentation of these compounds and, thus, facilitating structural identification of new compounds. Not all structural features of N-glycans can be revealed in a single ion-mobility/fragmentation experiment, the most obvious being the nature of the monosaccharide constituents. Consequently, work at extending the utility of the current methods to include such features is underway.
Professor Max Crispin, Centre for Biological Sciences, University of Southampton, UK.
Professor George R. Bousfield, Department of Biological Sciences, Wichita State University, USA.
Professor Paul Vouros, Department of Chemistry and Chemical Biology, Northeastern University, Boston USA.
Dr Weston B. Struwe, Department of Chemistry, University of Oxford, UK.
Professor Kevin Pagel, Institute of Chemistry and Biochemistry, Freie Universität Berlin, Germany.
Dr Snezana Vasiljevic, Department of Biochemistry (Glycobiology), University of Oxford, UK.
HARVEY DJ, SEABRIGHT G, CRISPIN M, STRUWE WB, 2018. Isomer information from ion mobility separation of high-mannose glycan fragments, J. Am. Soc. Mass Spectrom., 29, pp. 972-988.
BEHRENS A.-J, VASILJEVIC S, PRITCHARD LK, HARVEY DJ, ANDEV RS, KRUMM SA, STRUWE WB, CUPO A, KUMAR A, ZITZMANN N, SEABRIGHT GE, KRAMER HB, SPENCER DIR, ROYLE L, LEE JE, KLASSE PJ, BURTON DR, WILSON IA, WARD AB, SANDERS WR, MOORE JP, DOORES KJ, CRISPIN M. 2016. Composition and antigenic effects of individual glycan sites of the trimeric HIV-1 envelope, Cell Reports, 14, pp. 2695-2706.
HARVEY DJ, CRISPIN M, BONOMELLI C. SCRIVENS JH. 2015. Ion mobility mass spectrometry for ion recovery and clean-up of MS and MS/MS spectra obtained from low abundance viral samples, J. Am. Soc. Mass Spectrom., 26, pp. 1754-1767.
HUSSAIN S, MILLER JL, HARVEY DJ, GU Y, ROSENTHAL PB, ZITZMANN N, MCCAULEY JW. 2015. Strain-specific antiviral activity of iminosugars against human influenza A viruses, J. Antimicrob. Chemother., 70, pp. 136-152.
HOFMANN J, STRUWE WB, SCARFF CA, SCRIVENS JH, HARVEY DJ, PAGEL K. 2014. Estimating collision cross sections of negatively charged N-glycans using travelling wave ion mobility-mass spectrometry, Anal. Chem., 86, pp. 10789-10795.
WHEELER SF, DOMANN P, HARVEY DJ. 2009. Derivatization of sialic acids for stabilization in matrix-assisted laser desorption/ionization mass spectrometry and concomitant differentiation of α(2→3) and α(2→6) isomers. Rapid Commun. Mass Spectrom., 23, pp. 303-312.
HARVEY DJ, ROYLE L, RADCLIFFE CM, RUDD PM, DWEK RA 2008. Structural and quantitative analysis of N-linked glycans by matrix-assisted laser desorption ionization and negative ion nanospray mass spectrometry, Anal. Biochem,, 376, pp. 44-60.
HARVEY DJ. 2005. Fragmentation of negative ions from carbohydrates: Part 1; Use of nitrate and other anionic adducts for the production of negative ion electrospray spectra from N-linked carbohydrates, J. Am. Soc. Mass Spectrom., 16, pp. 622-630.
HARVEY DJ, BATEMAN RH, GREEN MR. 1997. High-energy collision-induced fragmentation of complex oligosaccharides ionized by matrix-assisted laser desorption/ionization mass spectrometry, J. Mass Spectrom, 32, pp. 167-187.
KÜSTER B, WHEELER SF, HUNTER AP, DWEK RA, HARVEY DJ. 1997. Sequencing of N-linked oligosaccharides directly from protein gels: In-gel deglycosylation followed by matrix-assisted laser desorption/ionisation mass spectrometry and normal-phase high performance liquid chromatography, Anal. Biochem., 250, pp. 82-101.
HARVEY DJ. 1993. Quantitative aspects of the matrix-assisted laser desorption mass spectrometry of complex oligosaccharides. Rapid Commun. Mass Spectrom., 7, pp. 614-619.
HARVEY DJ. 1982. Picolinyl esters as derivatives for the structural determination of long-chain branched and unsaturated fatty acids. Biomed. Mass Spectrom., 9, pp. 33-38.