This research program will investigate the photochemical mechanism by which visual pigments are transformed from an inactive state to a state which interacts with other extrinsic membrane proteins in visual receptors. The primary experimental tool which will be used in these studies is time-resolved absorption spectroscopy to investigate spectra and kinetics of intermediate species produced on time scales from nanoseconds to seconds following light absorption. Native bovine rhodopsin will be studied under a variety of conditions, as well artificial rhodopsins in which the native retinal chromophore is replaced by synthetically modified retinals. Rhodopsin variants in which specific protein residues are changed will also be studied. In addition to these bovine pigments, studies will be carried out on native and modified cone pigments, on mutant forms of pigments from drosophila, and on human rhodopsin. By studying the spectra and kinetics of pigments with this wide range of chromophore and protein residue substitutions, Dr. Kliger and coworkers hope to gain an understanding of the mechanism of rhodopsin function at a molecular level, and achieve a better perspective on how chromophore-protein interactions mediate the visual excitation process.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY000983-27
Application #
2888060
Study Section
Special Emphasis Panel (ZRG3-BBCA (01))
Project Start
1977-04-01
Project End
2001-09-29
Budget Start
1999-09-30
Budget End
2000-09-29
Support Year
27
Fiscal Year
1999
Total Cost
Indirect Cost
Name
University of California Santa Cruz
Department
Chemistry
Type
Schools of Arts and Sciences
DUNS #
City
Santa Cruz
State
CA
Country
United States
Zip Code
95064
Szundi, Istvan; Funatogawa, Chie; Guo, Ying et al. (2017) Protein Sequence and Membrane Lipid Roles in the Activation Kinetics of Bovine and Human Rhodopsins. Biophys J 113:1934-1944
Szundi, Istvan; Funatogawa, Chie; Kliger, David S (2016) Complexity of Bovine Rhodopsin Activation Revealed at Low Temperature and Alkaline pH. Biochemistry 55:5095-105
Szundi, Istvan; Li, Hai; Chen, Eefei et al. (2015) Platymonas subcordiformis Channelrhodopsin-2 Function: I. THE PHOTOCHEMICAL REACTION CYCLE. J Biol Chem 290:16573-84
Szundi, Istvan; Bogomolni, Roberto; Kliger, David S (2015) Platymonas subcordiformis Channelrhodopsin-2 (PsChR2) Function: II. RELATIONSHIP OF THE PHOTOCHEMICAL REACTION CYCLE TO CHANNEL CURRENTS. J Biol Chem 290:16585-94
Mooney, Victoria L; Szundi, Istvan; Lewis, James W et al. (2012) Schiff base protonation changes in Siberian hamster ultraviolet cone pigment photointermediates. Biochemistry 51:2630-7
Kliger, David S; Chen, Eefei; Goldbeck, Robert A (2012) Probing kinetic mechanisms of protein function and folding with time-resolved natural and magnetic chiroptical spectroscopies. Int J Mol Sci 13:683-97
Tsukamoto, Hisao; Szundi, Istvan; Lewis, James W et al. (2011) Rhodopsin in nanodiscs has native membrane-like photointermediates. Biochemistry 50:5086-91
Chen, Eefei; Goldbeck, Robert A; Kliger, David S (2010) Nanosecond time-resolved polarization spectroscopies: tools for probing protein reaction mechanisms. Methods 52:3-11
Szundi, Istvan; Epps, Jacqueline; Lewis, James W et al. (2010) Temperature dependence of the lumirhodopsin I-lumirhodopsin II equilibrium. Biochemistry 49:5852-8
Thomas, Yiren Gu; Szundi, Istvan; Lewis, James W et al. (2009) Microsecond time-resolved circular dichroism of rhodopsin photointermediates. Biochemistry 48:12283-9

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