Research Interests

• My main research area is to use biophysical spectroscopy techniques to determine the structure of proteins and to investigate conformational changes that accompany the function of proteins.  The primary technique that I use involves spectroscopic probes or labels that can report on the local environment of the protein and thereby provide dynamic structural information (Electron Paramagnetic Resonance (EPR)/Fluorescence/Phosphorescence Spectroscopy).  One such application of EPR that we use is the emerging technique of Site-Directed-Spin-Labeling EPR Spectroscopy (SDSL-EPR).  This technique has considerable promise for determining the structure of 'difficult' proteins i.e. those which are not amenable to the traditional atomic resolution structural techniques of NMR or X-ray crystallography.  Like other atomic-resolution structural techniques, SDSL-EPR can provide information on the secondary, tertiary and quaternary structure of proteins with the extra advantage that the measurements are performed in the proteins native environment.  By doing this, we can also measure conformational changes that may accompany the function of the protein on a biological relevant time scale. SDSL-EPR is also not limited by the size of the protein and can be performed on large protein complexes. I have recently used SDSL-EPR to investigate the structure of the muscle Troponin complex.  We are now using SDSL-EPR to probe the structure of ion channels in the membrane bilayer. We hope to correlate the structure of ion channels with biologically important events such as ion channel gating.

Selected Publications

• Structure of the Inhibitory region of Troponin by Site Directed Spin Labeling Electron Paramagnetic Resonance. L.J. Brown, K.L. Sale, R. Hills, C. Rouvierre, L. Song, Zhang X. & P.G. Fajer. Proceedings of the National Academy of Sciences USA, 99:12765-12770 (2002)
• Functional and spectroscopic studies of an FHC mutation in Motif X of cardiac Myosin Binding Protein-C. L.J. Brown, L. Singh, K. Sale, B. Yu, R. Trent, P.G. Fajer & B.D. Hambly.  European Biophysics Journal, 31:400-408 (2002)
• Independent movement of regulatory and catalytic domains of myosin heads revealed by phosphorescence anisotropy. L.J. Brown, N. Klonis, W.H. Sawyer, P.G. Fajer & B.D. Hambly. Biochemistry, 40:8283-8291 (2001)
• Intradomain distances in regulatory domain of myosin head in prepower and postpower stroke states: fluorescence energy transfer. T. Palm, K. Sale, L.J. Brown, B.D. Hambly, H. Li & P.G. Fajer. Biochemistry, 38:13026-13034 (1999)

Contact Details 

Mail Address

School of Physics
Protein Structure Group
Department of Biophysics
The University of New South Wales
SYDNEY 2052
Australia

Email Address

lbrown@phys.unsw.edu.au

Phone Number

61 2 9385 4587

Facsimile Number

61 2 9385 6060