Room 390 Parker Building
Winnipeg, Manitoba, Canada, R3T 2N2
Tel (204) 474-6697
Fax (204) 474-7608
E-mail: joneil@cc.umanitoba.ca
Below is the 3D structure of alamethicin, one of my all time favourite molecules!
(As determined by Fox and Richards, 1982 Nature 300, 325-330.)
Mathematica Notebooks
TEACHING: 2008-09
RESEARCH INTERESTS:
The main focus of my research is to understand the molecular structural basis of the biological activities of proteins. We use Nuclear Magnetic Resonance (NMR) spectroscopy, Circular Dichroism (CD) spectropolarimetry, molecular biology, and hydrogen exchange chemistry to measure the structures and dynamics of proteins, and to relate the information obtained to the actions of the proteins. The proteins under investigation are the membrane proteins, alamethicin and glycerol facilitator, and the RNA-binding protein, HIV-1 Tat.
1. Alamethicin: This fungal antibiotic peptide inserts into membranes and forms voltage-gated ion channels. We have investigated its structure and dynamics dissolved in methanol and detergent micelles and have completed a high-resolution structure determination of alamethicin in methanol. This work was possible because we developed methods to biosynthetically incorporate 15N and 13C into alamethicin and this was the first such labeling of a fungal protein. To gain insight into its function as a pore molecule we have synthesized dimers of the peptide that have been studied by NMR and CD. We have also collaborated with Professor Burkhard Bechinger (Max-Planck-Institut fur Biochemie, Martinsried, Germany) to determine, using solid-state NMR spectroscopy, the structure of alamethicin in a lipid bilayer.
2. Glycerol facilitator: Membrane proteins comprise about 25% of all prokaryotic and eukaryotic proteins yet studies of their structure and folding lag far behind those of water-soluble globular proteins. Glycerol facilitator is an intrinsic membrane protein found in E. coli and belongs to a large class of proteins that function to enhance the transport of polar solutes across non-polar membranes. We have developed an expression and purification system that has permitted us to study its secondary, tertiary, and quaternary structure and stability in several different detergents. We are exploring these preparations for the application of NMR spectroscopy.
3. Tat: The Transactivator of transcription (Tat) is a small RNA-binding protein that plays a central role in the regulation of HIV-1 replication and in approaches to treating latently-infected cells. To increase the dispersion of NMR signals and to permit dynamics analysis by multinuclear NMR spectroscopy we have prepared uniformly 15N and 15N/13C-labelled Tat1-72 protein. Our high-resolution NMR analyses of the dynamics of Tat show that it is a natively-unfolded protein.
4. Model Amides: We synthesized a series of hydrophobic model amides and studied their mechanisms of hydrogen-deuterium exchange by 1H NMR spectroscopy. This work showed for the first time that detergent micelles can slow the exchange process by restricting access of catalytic solvent to the interior of the micelle. This result has important implications for the use of hydrogen exchange of proteins in detergent.
http://home.cc.umanitoba.ca/~joneil/
