The basic goal of the work is to understand the factors affecting interfacial and transmembrane charge transfer in lipid bilayers. The work is potentially important, since the maintenance of ion gradients across membranes is one of the defining qualities of living systems. The approach characteristic of this work is the use of photoinduced transfer of electrons across lipid bilayers. This permits the study of internal electrostatic effects. In one phase of the work, it is proposed to apply this method to voltage gated ion channels, as an effort to gain photo-control over channel activity. The extension of the method to nerve cells is a possible direction of the research. A second avenue involves the further study and development of a device for electrostatic ion pumping that was created in Dr. Mauzerall's laboratory. Again, the ions are driven across the membrane by photoinduced charge transfer across an interface. This device allows the accurate calibration of electrostatic effects in transmembrane phenomena. The third project involves the determination of parameters of the biological ion pumps bacteriorhodopsin which pumps protons, and halorhodopsin which pumps chloride ions. The enthalpy and volume changes are associated with various steps undergone by these photoinduced pumps. These experiments will involve photoacoustic spectroscopy, a specialty of Dr. Mauzerall.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM025693-20
Application #
2770903
Study Section
Molecular and Cellular Biophysics Study Section (BBCA)
Project Start
1978-07-01
Project End
2001-08-31
Budget Start
1998-09-01
Budget End
1999-08-31
Support Year
20
Fiscal Year
1998
Total Cost
Indirect Cost
Name
Rockefeller University
Department
Microbiology/Immun/Virology
Type
Other Domestic Higher Education
DUNS #
071037113
City
New York
State
NY
Country
United States
Zip Code
10065
Hou, Harvey J M; Sakmar, Thomas P (2010) Methodology of pulsed photoacoustics and its application to probe photosystems and receptors. Sensors (Basel) 10:5642-67
Liu, Yan; Edens, Gregory J; Grzymski, Joseph et al. (2008) Volume and enthalpy changes of proton transfers in the bacteriorhodopsin photocycle studied by millisecond time-resolved photopressure measurements. Biochemistry 47:7752-61
Hou, Harvey J M; Mauzerall, David (2006) The A-Fx to F(A/B) step in synechocystis 6803 photosystem I is entropy driven. J Am Chem Soc 128:1580-6
Mauzerall, David; Liu, Yan; Edens, Gregory J et al. (2003) Measurement of enthalpy and volume changes in photoinitiated reactions on the ms timescale with a novel pressure cell. Photochem Photobiol Sci 2:788-90
Hou, J M; Boichenko, V A; Diner, B A et al. (2001) Thermodynamics of electron transfer in oxygenic photosynthetic reaction centers: volume change, enthalpy, and entropy of electron-transfer reactions in manganese-depleted photosystem II core complexes. Biochemistry 40:7117-25
Boichenko, V A; Hou, J M; Mauzerall, D (2001) Thermodynamics of electron transfer in oxygenic photosynthetic reaction centers: volume change, enthalpy, and entropy of electron-transfer reactions in the intact cells of the cyanobacterium Synechocystis PCC 6803. Biochemistry 40:7126-32
Hou, J M; Boichenko, V A; Wang, Y C et al. (2001) Thermodynamics of electron transfer in oxygenic photosynthetic reaction centers: a pulsed photoacoustic study of electron transfer in photosystem I reveals a similarity to bacterial reaction centers in both volume change and entropy. Biochemistry 40:7109-16
Sun, K; Mauzerall, D (1996) Evidence for ion chain mechanism of the nonlinear charge transport of hydrophobic ions across lipid bilayers. Biophys J 71:295-308
Sun, K; Mauzerall, D (1996) Charge transfer across a single lipid-water interface causes ion pumping across the bilayer. Biophys J 71:309-16
Sun, K; Mauzerall, D (1996) A simple light-driven transmembrane proton pump. Proc Natl Acad Sci U S A 93:10758-62

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