On the Rate Limiting Event in Protein Electron Transfer: Protein Dynamics vs. Electron Tunnelling

On the Rate Limiting Event in Protein Electron Transfer: /Protein Dynamics vs. Electron Tunnelling

Speaker: Daniel H. Murgida

Affiliation: INQUIMAE-Departamento de Química Inorgánica, Analítica y Química Física.
Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires -
CONICET

Host: Smilja Todorovic- Raman Spectroscopy Laboratory

Abstract:

Most of the current knowledge on protein electron transfer theory relies upon a number of assumptions, e.g. (a) the rate limiting step is dominated by electron tunnelling and (b) measurements in solution are a good approximation to the physiological conditions. In the last years, however, protein dynamics has been recognized a key factor in controlling inter- and intra-protein electron transfer kinetics for a number of cases. Moreover, a number of studies using biomimetic systems show that the electric fields present at biological membranes, e.g. in photosynthesis and mitochondrial respiration, are able to modulate ET dynamics.1
To address these issues we have developed an experimental strategy based on time-resolved surface-enhanced vibrational spectroelectrochemistry (SERR2 and SEIRA3). These methods allow for the simultaneous monitoring of redox, structural and orientational changes of a protein in a biomimetic construct under controlled electric fields and over a broad time range. The results are rationalized with the aid of steered molecular dynamics simulations and electronic coupling calculations.
In this talk I will show recent advances in our group on the dynamics of heterogeneous ET of heme proteins for which this combined experimental / theoretical approach has been applied.
 

References
1. Murgida, D.H; Hildebrandt, P. Chem. Soc. Rev. 2008, 37, 937.
2. Kranich, A.; Ly, H.K; Hildebrandt, P.; Murgida, D.H. J. Am. Chem. Soc. 2008, in press ( DOI: 10.1021/ja043959l)
3. Wisitruangsakul, N.; Zebger, I.; Ly, H.K.; Murgida, D.H.; Ekgasit, S.; Hildebrandt, P. Phys. Chem. Chem. Phys. 2008, in press (DOI: 10.1039/b806528d).

Short CV:

Education 1992 Licenciado in Chemistry.  School of Sciences, University of Buenos Aires.

1997 PhD in Chemistry  Department of Organic Chemistry, School of Sciences, University of Buenos Aires.  Herrero Ducloux Prize to the best PhD thesis in the country (Argentine Chemical Society)

Current Positions Since 07.2008: Vice-Director of the Institute of Physical Chemistry of Materials, Environment and Energy (INQUIMAE, CONICET-UBA)
Since 09.2007: Professor of Chemistry. Department of Inorganic, Analytical and Physical Chemistry. School of Sciences, University of Buenos Aires.
Since 04.2007: Independent Researcher of CONICET at INQUIMAE
Since 2003: Visiting Professor of ITQB
Previous Positions 2003-2007 Assistant Professor (Beamter C2). Max Volmer Laboratory of Biophysical Chemistry, Technical University of Berlin, Germany.
2001-2003 Investigador Auxiliar. ITQB, Portugal.
1999-2001 Alexander von Humboldt Fellow. Max Planck Institute of Bioinorganic Chemistry, Germany.
1998Post-doc researcher. University of Parma, Italy.
1991-1998 Research Fellow of the University of Buenos Aires. Department of Organic Chemistry, School of Sciences, University of Buenos Aires, Argentina.
1988-1998 Department of Organic Chemistry, School of Sciences, University of Buenos Aires, Argentina.
Scientific Interests -Biophysical Chemistry. -Bioelectrochemistry -Vibrational spectroscopy. -Photochemistry and Photobiology. -Nanoscience and nanotechnology.
Publications More than 60 articles in international journals.