Abstract

Femtosecond pump-probe experiments on rhodopsin are elucidating the mechanism of the first step in vision, which is a 200 femtosecond cis-trans isomerization of the retinal moiety of the protein. Anisotropy techniques are being used to study the reorientation of the retinal backbone during the reaction. Visible pump/ infrared probe techniques are being used to further study structural issues related to retinal motion. In this context, especially important will be probing of hydrogen-out of plane vibrations, which are very sensitive to backbone conformation of the retinal. Also, protein vibrational modes are being investigated as indicators or protein group involvement in the chemical process. To better characterize the potential energy surface of the reaction, absorption and emission spectra of the first reaction product, bathorhodopsin, are being recorded over an extended wavelength region. Based on all these measurements we are developing a coherent picture of the factors affecting this key reaction in visual phototransduction.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Center for Research Resources (NCRR)
Type
Biotechnology Resource Grants (P41)
Project #
5P41RR001348-17
Application #
6281091
Study Section
Project Start
1998-08-01
Project End
1999-07-31
Budget Start
1997-10-01
Budget End
1998-09-30
Support Year
17
Fiscal Year
1998
Total Cost
Indirect Cost

  Institution

Name
University of Pennsylvania
Department
Type
DUNS #
042250712
City
Philadelphia
State
PA
Country
United States
Zip Code
19104

  Publications

Sheth, Rahul A; Arellano, Ronald S; Uppot, Raul N et al. (2015) Prospective trial with optical molecular imaging for percutaneous interventions in focal hepatic lesions. Radiology 274:917-26
Roussakis, Emmanuel; Spencer, Joel A; Lin, Charles P et al. (2014) Two-photon antenna-core oxygen probe with enhanced performance. Anal Chem 86:5937-45
Courter, Joel R; Abdo, Mohannad; Brown, Stephen P et al. (2014) The design and synthesis of alanine-rich ?-helical peptides constrained by an S,S-tetrazine photochemical trigger: a fragment union approach. J Org Chem 79:759-68
Singh, Prabhat K; Kuroda, Daniel G; Hochstrasser, Robin M (2013) An ion's perspective on the molecular motions of nanoconfined water: a two-dimensional infrared spectroscopy study. J Phys Chem B 117:9775-84
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
Falvo, Cyril; Zhuang, Wei; Kim, Yung Sam et al. (2012) Frequency distribution of the amide-I vibration sorted by residues in amyloid fibrils revealed by 2D-IR measurements and simulations. J Phys Chem B 116:3322-30

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