| Professor
Steel directs the Biomolecular Laser Spectroscopy Laboratory jointly
with Professor Gafni from Biological Chemistry. Research using advanced
laser spectroscopy techniques is designed to provide insight into
fundamental questions associated with protein structure and dynamics
and related issues including protein-protein and protein-DNA
interactions and the general problem of biomolecular recognition.
Experiments and designed to explore the nature of structural changes
that occur as a result, for example, of aging, or other factors that
lead to well known diseases such as Alzheimer's, cystic fibrosis and
mad cow. Recent work includes their development of new laser techniques
which enabled the group to discover that some proteins undergo
structural changes following synthesis and biological activation in
ways that were not detected by other methods. The groups primary laser
based experimental approach is based on single molecule spectroscopy.
Current work is now focusing specifically on understanding the origin
of cellular toxicity in amyloidogenic diseases including Alzheimer's
and type 2 diabetes. These diseases are characterized by protein
deposits (plaques, etc) in the target tissue. The historical hypothesis
has been that these deposits are the origin of the pathology. However,
recent results suggest that the origin of cellular toxicity arises from
the formation of small oligomers a long time before for the formation
of the deposits. The small oligomers have been hypothesized to
permeabilize the cellular membrane, leading to cell death. Studying the
oligomers by conventional means is extremely challenging because they
are highly heterogeneous, occur in small concentrations and have only a
short life. Single molecule spectroscopy is perfect for the study of
these structures. Our work is aimed at following the
development of these oligomers and correlating the structure with the
onset of cellular interactions and cell death. |
C.J.
Fischer, J.A. Schauerte, D.G. Steel, A. Gafni, “The triplet-state
lifetime of indole in aqueous and viscous environments: significance to
the interpretation of room temperature phosphorescence in proteins,” J.
Am. Chem. Soc. 124 pp 10359-10366 (2002).
Jue Shi, Bruce A.
Palfey, Joseph Dertouzos, Ari Gafni, and Duncan Steel, “Single molecule
study of kinetics and mechanism of dihydroorotate dehydrogenase
(DHOD),” Journal of the American Chemical Society 126, 6914-6922 (2004)
Jeffrey
R. Brender, Joe Dertouzos, David P. Ballou, Vincent Massey, Bruce A.
Palfey, Barrie Entsch Ari Gafni, and Duncan Steel, “Conformational
Dynamics of the Isoalloxazine Ring in Substrate-free PHBH: Single
Molecule Studies”, JACS 27, pp18171-18178 (2005).
Jue Shi, Ari
Gafni, and Duncan Steel, “Simulated Data Sets for Single Molecule
Kinetics: Some Limitations and Complications of Data Analysis,”
European Biophysics Journal, in press (2006).
Jue Shi, Joe
Dertouzos, Ari Gafni, Duncan Steel, Bruce A. Palfey “Single-Molecule
Kinetics Reveals New Signatures of Half-sites Reactivity in
Dihydroorotate Dehydrogenase A Catalysis,” Proc. National Academy of
Sciences, USA 103 pp5775-5780 (2006).
Jue Shi, Gafni, A. and
Steel, DG: Application of single molecule spectroscopy in studies of
enzyme kinetics and mechanisms. Meth. Enzymol. 2006, in press.
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