Dr Hudson's Research Interests

Gas-phase studies of isolated biomolecules

The isolation of molecules under cold conditions in vacuo provides a way to use laser spectroscopy to investigate various aspects of nuclear motions and electronic structure. We apply this approach to study properties of important functional groups in proteins. Presently, we are interested in the derivatives of porphyrin – related to the functional groups of haemoglobin (oxygen transport in blood) and chlorophyll (light harvesting in plants). Multi-photon ionization and hole-burning methods are used in the first instance to identify the various conformational states of the porphyrin under isolated conditions. Other methods are then used to obtain an insight into pathways for structural isomerisation and electronic decay from photoexcited states.Chem Bio- Biophototonics

Current support: The Engineering and Physical Sciences Research Council & the Central Laser Facility.

Graduate Student: Joseph Beames.

Collaborator: Prof John Simons, University of Oxford.

Single-molecule fluorescence microscopy

Differences in chemical reactivity might arise from small variations in the tertiary structure of a protein (the 3D folding). However, the molecular dynamics of individual copies of a protein are not revealed in the majority of experimental measurements. Instead, the results will usually reflect the ensemble average across the entire population of molecules in a sample. It is the objective of single-molecule research to reveal the differences (i.e. heterogeneity) in an ensemble, and we are using specialised techniques in fluorescence spectroscopy to achieve this. In collaborations with molecular biologists, we are investigating the repair of damaged DNA initiated by helicase/nuclease enzymes, and protein trafficking inside the cell. We also use single molecule methods to achieve sub-diffraction limited imaging of bioorganic structures, and enable the tracking of molecular motors in vivo.

Current support: The Wellcome Trust & HEFCE Capital Investment Fund, University of Leicester.

Collaborators: Dr Maxim Ryadnov, University of Leicester, and Drs Mark Dillingham, Mark Szczelkun and David Stephens, and Prof Dek Woolfson, University of Bristol.

V. Gupta, P. Spence, M. J. Wozniak, K. J. Palmer, V. J. Allan, A. J. Hudson and D. J. Stephens (2008) “Kinesin-1 (uKHC/Kif5b) is required for bidirectional motility of ER exit sites and efficient ER-to-Golgi transport” Traffic 9, 1850.

P. Spence, V. Gupta, D. J. Stephens, and A. J. Hudson (2008) “In Vivo Tracking of Fluorescent Proteins by 2D Gaussian Fitting of Digital Images: Application to COPII-Coated Endoplasmic Reticulum Exit Sites” Eur. Biophys. J. 37, 1335.

Optical trapping and spectroscopy of liquid microdroplets

Optical forces can be used to manipulate particles in an emulsion or aerosol and it is possible to suspend a single droplet of liquid in the waist of a tightly-focussed beam from a laser. This technique is referred to as optical tweezing and, in collaboration with Dr Reid, we are using it to characterise the properties of single droplets from an aerosol containing a mixture of aqueous and organic components. This has led to the development of novels methods for spectroscopic analysis and imaging of microparticles. In addition, our group has combined optical tweezing of liquid microparticles with methods for the sensitive detection of the fluorescence from a single molecule. We intend to use this approach to investigate Brownian motion of molecules in different liquid droplets and the conformational dynamics of a single copy of a protein in a confined volume of solvent.

Current support: HEFCE Capital Investment Fund, University of Leicester.

Student: Nilesh Mistry.

Collaborators: Dr Jonathan Reid, University of Bristol, Dr David McGloin and Paul Campbell, University of Dundee, and Profs Clive Bagshaw and Ian Eperon, University of Leicester.

A. J. Hudson (2008) Faraday Disc. Chem. Soc. 137, 413.

K. J. Knox, J. P. Reid, K. L. Hanford, A. J. Hudson, & L. Mitchem (2007) “Direct measurements of the axial displacement and evolving size of optically-trapped aerosol droplets” J. Optics A: Pure and App. Optics 9, S180.

Career History and Awards

I was awarded an EPSRC Advanced Research Fellowship in 2005 and I am a Lecturer in the Department of Chemistry at the University of Leicester. Current interests include the spectroscopy and dynamics of isolated biomolecules, optical tweezing and spectroscopy of liquid microdroplets, and applications of fluorescence microscopy for single-molecule detection and chemical sensing.

My training in physical chemistry was received in the group headed by John Polanyi (Nobel Laureate, 1986) at the University of Toronto in Canada; from whence I obtained a Ph.D. in 1998. This was followed by two periods of postdoctoral research in fundamental and applied photochemistry. The first of these was taken in the Polanyi group and, the second, in the Department of Mechanical and Industrial Engineering (Toronto) in the applied area of photo-polymerisation of adhesives. I was also an OCE† Industrial Fellow in 2000-01, a Materials Scientist in a fibre optics company from 2001-02 and a Senior Scientist in a start-up biomedical company in North America from 2002-05. (†Ontario Centre of Excellence in Materials and Manufacturing)

Career Summary

DatesPostLocation
Oct 2008 - Present EPSRC Advanced Research Fellow & Lecturer Department of Chemistry, University of Leicester
Sep 2005 - Oct 2008 EPSRC Advanced Research Fellow School of Chemistry, University of Bristol
Mar 2002 - Aug 2005 Senior Scientist NovX Systems, Markham, Ontario, Canada
Sep 2001 - Mar 2002 Materials Scientist NovX Systems, Markham, Ontario, Canada
Aug 2000 - Sep 2001

Postdoctoral Research Fellow (Mentors : Prof Jan Spelt & Dr Manfred Hubert)

Department of Mechanical Engineering, University of Toronto, Canada
Sep 1998 - Jul 2000

Postdoctoral Research Fellow (Mentor: Prof John C Polyani)

Department of Chemistry, University of Toronto, Canada

 

Awards

EPSRC Advanced Research Fellowship, 2005-2010
Industrial Fellowship, Materials and Manufacturing Ontario, 2000-2001.
F. E. Beamish Prize in Physical Chemistry, University of Toronto, 1998.
Teaching Award, University of Toronto, 1996.
University of Toronto Open Fellowship, 1997-1998.
University of Toronto International Student Award, 1994-1998.
British Gas Research Scholarship, 1994-1997.
Book Award, Oxford University, 1993.
Book Award, New College, Oxford University, 1993 &1994.
Scholarship from New College, Oxford University, 1991-1994.

Selected Recent Publications

  • J. M. Beames and A. J. Hudson, “Jet Cooled Spectroscopy of Paracetamol”, submitted (2009).
  • J. M. Beames and A. J. Hudson, “Jet Cooled Spectroscopy of the Excitonic States in a Cyclic Trimolecule”, in preparation (2009).
  • J. M. Beames, A. J. Hudson, J. P Simons and T. D. Vaden, “Infra-Red Ion Dip Spectroscopy of Jet-Cooled Porphyrins”, in preparation (2009).
  • J. M. Beames, T. D. Vaden and A. J. Hudson, “The Spectroscopy of Porphyrins in Molecular Beams: An Insight into the Vibronic Structure of the Q Band”, Journal of Porphyrins and Phthalocyanines, submitted (2009).
  • J. M. Beames, M. G. D. Nix and A. J. Hudson, “Comparison of the REMPI spectra of pyrrole and 2,5-dimethylpyrrole: Building towards an understanding of the electronic structure and photochemistry of porphyrins”, J. Chem. Phys. 131, 174305 (2009).
  • P. Spence, V. Gupta, D. J. Stephens, and A. J. Hudson, “In Vivo Tracking of Fluorescent Proteins by 2D Gaussian Fitting of Digital Images: Application to COPII-Coated Endoplasmic Reticulum Exit Sites”, Eur. Biophys. J. 37, 1335 (2008).
  • V. Gupta, P. Spence, M. J. Wozniak, K. J. Palmer, V. J. Allan, A. J. Hudson and D. J. Stephens, “Kinesin-1 (uKHC/Kif5b) is required for bidirectional motility of ER exit sites and efficient ER-to-Golgi transport”, Traffic 9, 1850 (2008).
  • A. J. Hudson, Faraday Discussions of the Chemical Society 137, 413 (2008).
  • K. J. Knox, J. P. Reid, K. L. Hanford, A. J. Hudson and L. Mitchem, “Direct measurements of the axial displacement and evolving size of optically-trapped aerosol droplets”, J. Optics A: Pure and App. Optics 9, S180 (2007).
  • Canadian, US and International Patents (pending) US20060210435 and WO/2006/094388, Automated Analyzer (Filed: March 7th 2006). This describes the intellectual property associated with an instrument (iMDx, Novx Systems, Markham, Ontario, Canada) for point-of-care detection of drugs of abuse.
  • Canadian and US Patent Application US2003168939, Device and method of driving piezoelectric actuators for fast switching of wavelengths in a fiber-Bragg grating (Filed: Dec. 10th 2002, published: Sept. 11th 2003). This describes the intellectual property associated with an optical communications module (ROADX 1010 and 1050).

Share this page:

Contact details

Dr A. Hudson
Department of Chemistry
University of Leicester
LEICESTER
LE1 7RH

tel: 0116 252 2099

email: ah242@le.ac.uk