Faculty

Ashok Deniz 
Associate Professor
Department of Molecular Biology
TSRI - 1999

Education 
B.Sc. St. Xaviers College (University of Bombay), 1988

M. Sc. Indian Institute of Technology, Bombay, 1990

Ph.D. University of Chicago, 1996

Research Focus 
Single-Molecule Biophysics
Our main research focus is on elucidating the
detailed mechanisms of key biological processes, such as protein folding, biological assembly and cellular protein dynamics, using high-sensitivity single-molecule fluorescence methods. These novel state-of-the-art methods, in combination with techniques from chemistry and biology, provide us with unprecedented abilities to directly probe heterogeneity and dynamics in biological processes. One research effort of the laboratory is to apply single-molecule fluorescence resonance energy transfer (FRET) methods to explore protein and RNA folding energy landscapes. The distance dependence of FRET can be used to monitor the conformational properties of individual molecules, allowing us to address fundamental questions about folding mechanisms and partially folded structures. We also apply single molecule methods to study protein-nucleic acid and protein-protein interactions, and to study the assembly of molecular machines important in cellular function. For example, we are trying to understand how ribosomal subunits are assembled from their constituent rRNA and complement of several proteins. Finally, we are interested in using single molecule imaging methods to directly visualize the dynamics of individual receptors and other components involved in cellular signalling and function.

Selected References 
Deniz, A.A., Dahan, M., Grunwell, J.R., Ha, T.J., Faulhaber, A.E., Chemla, D.S., Weiss, S. and Schultz, P.G. “Single-pair fluorescence resonance energy transfer on freely diffusing molecules: Observation of Förster distance dependence and subpopulations” Proc. Natl. Acad. Sci. 96:3670, 1999.

Deniz, A.A., Laurence, T., Beligere, G.S., Dahan, M., Martin, A.B., Chemla, D.S., Dawson, P.E., Schultz, P.G. and Weiss, S. “Single molecule protein folding: Diffusion fluorescence resonance energy transfer studies of the denaturation of Chymotrysin Inhibitor 2” Proc. Natl. Acad. Sci. 97:5179, 2000.

Deniz A.A., Laurence T.A., Dahan M., Chemla D.S., Schultz P.G., Weiss S. “Ratiometric Single-Molecule Studies of Freely Diffusing Biomolecules” Annu. Rev. Phys. Chem. 52:233, 2001.

Pljevaljcic, G, Millar, DP, Deniz, AA. "Freely-diffusing single hairpin ribozymes provide insights into the role of secondary structure and partially folded states in RNA folding" Biophysical Journal 87:457-467, 2004.