The nature of the chromophore binding sites and the primary photochemical events of rhodopsin, bacteriorhodopsin and the Xenopus violet cone pigment, viodopsin, will be studied by using spectroscopic and theoretical techniques. The goals are to understand the photophysical properties of the bound chromophores. The principal spectroscopic methods to be used in these studies include two-photon spectroscopy, Stark effect spectroscopy, Fourier transform infra-red spectroscopy, microwave spectroscopy, and pulsed laser photocalorimetry. The principal chemical studies to be undertaken include organic cation and chromophore analog substitutions, as well as site directed mutagenesis. The theoretical methods include semiempirical molecular orbital theory and molecular dynamics theory. The goal is to combine experiment and theory in a synergistic program which enhances both. In addition to the more global goals outlined above, Dr. Birge will seek to answer the following specific questions: (1) What is the principal mechanism of wavelength modulation in the blue and violet cones? (2) Where are the cation binding sites in bacteriorhodopsin, and how do these sites mediate the properties of the bound chromophore? (3) Is there a chloride binding site in viodopsin, and what impact does this site have on the photophysical properties of the chromophore? (4) What are the molecular origins of energy storage in the primary events of these three proteins? (5) What is the principal molecular mechanism of dark noise in vertebrate and invertebrate vision? (6) What are the molecular origins of the unusual photochemical properties of the 4-keto retinal bacteriorhodopsin analog? (7) Can one improve the accuracy of the MNDO-PSDCI semi-empirical molecular orbital theory by using ab-initio effective Hamiltonian parameterizaion?

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
2R01GM034548-13A1
Application #
2632906
Study Section
Molecular and Cellular Biophysics Study Section (BBCA)
Project Start
1988-08-01
Project End
2001-02-28
Budget Start
1998-03-01
Budget End
1999-02-28
Support Year
13
Fiscal Year
1998
Total Cost
Indirect Cost
Name
Syracuse University
Department
Chemistry
Type
Schools of Arts and Sciences
DUNS #
002257350
City
Syracuse
State
NY
Country
United States
Zip Code
13244
Trieu, Melissa M; Devine, Erin L; Lamarche, Lindsey B et al. (2017) Expression, purification, and spectral tuning of RhoGC, a retinylidene/guanylyl cyclase fusion protein and optogenetics tool from the aquatic fungus Blastocladiella emersonii. J Biol Chem 292:10379-10389
Greco, Jordan A; LaFountain, Amy M; Kinashi, Naoto et al. (2016) Spectroscopic Investigation of the Carotenoid Deoxyperidinin: Direct Observation of the Forbidden S0 ? S1 Transition. J Phys Chem B 120:2731-44
Greco, Jordan A; Rossi, Alison; Birge, Robert R et al. (2014) A spectroscopic and theoretical investigation of a free-base meso-trithienylcorrole. Photochem Photobiol 90:402-14
Sandberg, Megan N; Greco, Jordan A; Wagner, Nicole L et al. (2014) Low-Temperature Trapping of Photointermediates of the Rhodopsin E181Q Mutant. SOJ Biochem 1:
Magdaong, Nikki M; LaFountain, Amy M; Greco, Jordan A et al. (2014) High efficiency light harvesting by carotenoids in the LH2 complex from photosynthetic bacteria: unique adaptation to growth under low-light conditions. J Phys Chem B 118:11172-89
Ranaghan, Matthew J; Greco, Jordan A; Wagner, Nicole L et al. (2014) Photochromic bacteriorhodopsin mutant with high holographic efficiency and enhanced stability via a putative self-repair mechanism. ACS Appl Mater Interfaces 6:2799-808
Magdaong, Nikki M; Niedzwiedzki, Dariusz M; Greco, Jordan A et al. (2014) Excited state properties of a short ?-electron conjugated peridinin analogue. Chem Phys Lett 593:132-139
Kuemmel, Colleen M; Sandberg, Megan N; Birge, Robert R et al. (2013) A conserved aromatic residue regulating photosensitivity in short-wavelength sensitive cone visual pigments. Biochemistry 52:5084-91
Wagner, Nicole L; Greco, Jordan A; Ranaghan, Matthew J et al. (2013) Directed evolution of bacteriorhodopsin for applications in bioelectronics. J R Soc Interface 10:20130197
Wagner, Nicole L; Greco, Jordan A; Enriquez, Miriam M et al. (2013) The nature of the intramolecular charge transfer state in peridinin. Biophys J 104:1314-25

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