Abstract

The electron transfer fromQA to QB in photosynthetic reactioncenters provides a good reaction for the study of the coupling of electron and proton transfer. Since the same species of quinone is found in both sites, the traditional methods for monitoring the reaction rely on Stark shifts in the spectra of nearby chromophores. However, Stark shifts cannot distinguish between electron and proton transfers. Replacement of the occupants of QA and QB with compounds with different semiquinone spectra allows direct monitoring of the electron transfer. We have characterized the electron transfer with these reaction centers. However, only 50% of the expected amplitude is seen, so part of the reaction occurs faster than our instrument response time (20 ms). This is unexpectedly fast and suggests that the older, indirect methods of measurement missed early time process. We would like to use the RLBL facilities to look for and the characterize these faster kinetic components.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Center for Research Resources (NCRR)
Type
Biotechnology Resource Grants (P41)
Project #
5P41RR001348-15
Application #
5223305
Study Section
Project Start
Project End
Budget Start
Budget End
Support Year
15
Fiscal Year
1996
Total Cost
Indirect Cost

  Publications

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Chuntonov, Lev; Ma, Jianqiang (2013) Quantum process tomography quantifies coherence transfer dynamics in vibrational exciton. J Phys Chem B 117:13631-8
Culik, Robert M; Annavarapu, Srinivas; Nanda, Vikas et al. (2013) Using D-Amino Acids to Delineate the Mechanism of Protein Folding: Application to Trp-cage. Chem Phys 422:
Kuroda, Daniel G; Bauman, Joseph D; Challa, J Reddy et al. (2013) Snapshot of the equilibrium dynamics of a drug bound to HIV-1 reverse transcriptase. Nat Chem 5:174-81
Lam, A R; Moran, S D; Preketes, N K et al. (2013) Study of the ?D-crystallin protein using two-dimensional infrared (2DIR) spectroscopy: experiment and simulation. J Phys Chem B 117:15436-43
Kuroda, Daniel G; Singh, Prabhat K; Hochstrasser, Robin M (2013) Differential hydration of tricyanomethanide observed by time resolved vibrational spectroscopy. J Phys Chem B 117:4354-64
Goldberg, Jacob M; Speight, Lee C; Fegley, Mark W et al. (2012) Minimalist probes for studying protein dynamics: thioamide quenching of selectively excitable fluorescent amino acids. J Am Chem Soc 134:6088-91

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