The aim of this proposal is to extend the understanding of the structure and function of cytochrome P450 and other heme protein systems by using Raman spectroscopy and femtosecond coherence spectroscopy (FCS), which directly probes the coherent protein/cofactor vibrational motion induced by electronic transitions associated with biochemical reactions. Overall, this project has a wide range of health related implications involving P450 in particular and hemes in general. Many chemotherapeutic agents as well as polycyclic carcinogens are metabolized by P450 systems. Moreover, all metabolic disorders involving a P450 protein relate to this work since a fundamental understanding of the active site structure and function of P450 at the molecular level will result in better insight for those concerned with treatment of these disorders at any level. These studies will employ spectroscopic measurements that allow key, reaction specific electronic and electron-nuclear coupling parameters to be extracted from the combination of x-ray structure and FCS data. Careful studies of the reaction and field driven coherences as a function of temperature, viscosity, and protein perturbations will be carried out in order to better assign and understand the nature of the coherent states that are formed as the reactions proceed. Time resolved protein dynamics and kinetics will be followed over many orders of magnitude, from femtoseconds to kiloseconds, and novel double-pulse kinetics experiments will be used to probe rapidly reacting subpopulations of the ensemble so that protein conformational interconversion times are directly revealed. Theoretical work involving ligand binding and dissociation in heme proteins, reaction coherence, electron transfer, and resonant light-matter interactions will also be pursued.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
5R01DK035090-18
Application #
6329326
Study Section
Special Emphasis Panel (ZRG3-BMT (02))
Program Officer
Sechi, Salvatore
Project Start
1984-06-01
Project End
2003-11-30
Budget Start
2000-12-01
Budget End
2001-11-30
Support Year
18
Fiscal Year
2001
Total Cost
$292,167
Indirect Cost
Name
Northeastern University
Department
Physics
Type
Schools of Arts and Sciences
DUNS #
039318308
City
Boston
State
MA
Country
United States
Zip Code
02115
Karunakaran, Venugopal; Sun, Yuhan; Benabbas, Abdelkrim et al. (2014) Investigations of the low frequency modes of ferric cytochrome c using vibrational coherence spectroscopy. J Phys Chem B 118:6062-70
Sun, Yuhan; Zeng, Weiqiao; Benabbas, Abdelkrim et al. (2013) Investigations of heme ligation and ligand switching in cytochromes p450 and p420. Biochemistry 52:5941-51
Zeng, Weiqiao; Sun, Yuhan; Benabbas, Abdelkrim et al. (2013) Investigations of ferric heme cyanide photodissociation in myoglobin and horseradish peroxidase. J Phys Chem B 117:4042-9
Sun, Yuhan; Karunakaran, Venugopal; Champion, Paul M (2013) Investigations of the low-frequency spectral density of cytochrome c upon equilibrium unfolding. J Phys Chem B 117:9615-25
Benabbas, Abdelkrim; Karunakaran, Venugopal; Youn, Hwan et al. (2012) Effect of DNA binding on geminate CO recombination kinetics in CO-sensing transcription factor CooA. J Biol Chem 287:21729-40
Barabanschikov, Alexander; Demidov, Alexander; Kubo, Minoru et al. (2011) Spectroscopic identification of reactive porphyrin motions. J Chem Phys 135:015101
Karunakaran, Venugopal; Benabbas, Abdelkrim; Youn, Hwan et al. (2011) Vibrational coherence spectroscopy of the heme domain in the CO-sensing transcriptional activator CooA. J Am Chem Soc 133:18816-27
Karunakaran, Venugopal; Denisov, Ilia; Sligar, Stephen G et al. (2011) Investigation of the low frequency dynamics of heme proteins: native and mutant cytochrome P450(cam) and redox partner complexes. J Phys Chem B 115:5665-77
Benabbas, Abdelkrim; Ye, Xiong; Kubo, Minoru et al. (2010) Ultrafast dynamics of diatomic ligand binding to nitrophorin 4. J Am Chem Soc 132:2811-20
Karunakaran, Venugopal; Benabbas, Abdelkrim; Sun, Yuhan et al. (2010) Investigations of low-frequency vibrational dynamics and ligand binding kinetics of cystathionine beta-synthase. J Phys Chem B 114:3294-306

Showing the most recent 10 out of 33 publications