Primary light induced processes in hemoproteins and bacteriorhodopsin will be explored using novel femtosecond laser methods particularly infrared spectroscopy. The goal is to elucidate mechanisms of energy relaxation and transport including energy flowing within proteins, from proteins to the surrounding medium and within the medium. Information will be obtained about protein conformational changes and motions within nucleic acids based on bond reorientation amplitudes and frequencies. Specifically, the ligand dissociation and rebinding in CO and NO myoglobin and hemoglobin will be studied to discover whether there are electronic barriers to recombination and if the ligand kinetics is controlled by equilibrium fluctuations or by the relaxation of the protein structure. Direct observations of ligands CO and NO with transient IR spectroscopy will allow these ligands to be seen commuting in and out of the protein. Polarized infrared pump experiments are aimed at establishing the structural details and timescales of molecular reorientations occurring within the hemepockets of Hb and Mb, and of the energy flow within the protein following ligand reactions. Studies of bacteriorhodopsin will use IR methods to further characterize the early steps in the photocycle but an important goal is the determination of isomerization induced changes in protein structure, not previously possible. Vibrational excitations of specific bonds of ions, protein constituents and nucleic acids will be used to obtain new information on orientational dynamics in these systems. All the proposed work can be brought into relationship with theoretical simulations of the dynamcis.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Method to Extend Research in Time (MERIT) Award (R37)
Project #
2R37GM012592-28
Application #
3484120
Study Section
Molecular and Cellular Biophysics Study Section (BBCA)
Project Start
1977-02-01
Project End
1997-01-31
Budget Start
1992-02-01
Budget End
1993-01-31
Support Year
28
Fiscal Year
1992
Total Cost
Indirect Cost
Name
University of Pennsylvania
Department
Type
Schools of Arts and Sciences
DUNS #
042250712
City
Philadelphia
State
PA
Country
United States
Zip Code
19104
Chuntonov, Lev; Pazos, Ileana M; Ma, Jianqiang et al. (2015) Kinetics of exchange between zero-, one-, and two-hydrogen-bonded states of methyl and ethyl acetate in methanol. J Phys Chem B 119:4512-20
Ghosh, Ayanjeet; Tucker, Matthew J; Gai, Feng (2014) 2D IR spectroscopy of histidine: probing side-chain structure and dynamics via backbone amide vibrations. J Phys Chem B 118:7799-805
Ma, Jianqiang; Pazos, Ileana M; Gai, Feng (2014) Microscopic insights into the protein-stabilizing effect of trimethylamine N-oxide (TMAO). Proc Natl Acad Sci U S A 111:8476-81
Ghosh, Ayanjeet; Wang, Jun; Moroz, Yurii S et al. (2014) 2D IR spectroscopy reveals the role of water in the binding of channel-blocking drugs to the influenza M2 channel. J Chem Phys 140:235105
Pazos, Ileana M; Ghosh, Ayanjeet; Tucker, Matthew J et al. (2014) Ester carbonyl vibration as a sensitive probe of protein local electric field. Angew Chem Int Ed Engl 53:6080-4
Ma, Jianqiang; Komatsu, Hiroaki; Kim, Yung Sam et al. (2013) Intrinsic structural heterogeneity and long-term maturation of amyloid ? peptide fibrils. ACS Chem Neurosci 4:1236-43
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
Kuroda, Daniel G; Abdo, Mohannad; Chuntonov, Lev et al. (2013) Vibrational dynamics of a non-degenerate ultrafast rotor: the (C12,C13)-oxalate ion. J Chem Phys 139:164514
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
Chuntonov, Lev; Kuroda, Daniel G; Ghosh, Ayanjeet et al. (2013) Quantum Beats and Coherence Decay in Degenerate States Split by Solvation. J Phys Chem Lett 4:1866-1871

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