The membrane properties which control Ca2 ion uptake and ATPase activities by sarcoplasmic reticulum Ca2 ion-ATPase are investigated in a reconstituted vesicular bilayer system. The affinities of different lipids for binding sites on the enzyme are determined using a new fluorescence quenching method. The influence of pH and certain ions, especially calcium, on lipid behavior is examined using proton nuclear magnetic resonance (1HNMR) spectroscopy to detect individual lipids in a perdeuterated phospholipid matrix. It will then be possible to examine how enzyme activity and lipid binding to the enzyme can be influenced by electrostatic effects such as cation concentration and pH which have been implicated in pathological cardiac conditions.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL018255-17
Application #
3335569
Study Section
Biophysical Chemistry Study Section (BBCB)
Project Start
1978-05-01
Project End
1994-11-30
Budget Start
1991-12-23
Budget End
1992-11-30
Support Year
17
Fiscal Year
1992
Total Cost
Indirect Cost
Name
Cornell University
Department
Type
Schools of Arts and Sciences
DUNS #
City
Ithaca
State
NY
Country
United States
Zip Code
14850
Dibble, A R; Feigenson, G W (1994) Detection of coexisting fluid phospholipid phases by equilibrium Ca2+ binding: peptide-poor L alpha and peptide-rich HII phase coexistence in gramicidin A'/phospholipid dispersions. Biochemistry 33:12945-53
Hinderliter, A K; Huang, J; Feigenson, G W (1994) Detection of phase separation in fluid phosphatidylserine/phosphatidylcholine mixtures. Biophys J 67:1906-11
Huang, J; Swanson, J E; Dibble, A R et al. (1993) Nonideal mixing of phosphatidylserine and phosphatidylcholine in the fluid lamellar phase. Biophys J 64:413-25
Dibble, A R; Yeager, M D; Feigenson, G W (1993) Partitioning of gramicidin A' between coexisting fluid and gel phospholipid phases. Biochim Biophys Acta 1153:155-62
Huang, J; Feigenson, G W (1993) Monte Carlo simulation of lipid mixtures: finding phase separation. Biophys J 65:1788-94
Caffrey, M; Hogan, J; Rudolph, A S (1991) Diacetylenic lipid microstructures: structural characterization by X-ray diffraction and comparison with the saturated phosphatidylcholine analogue. Biochemistry 30:2134-46
Swanson, J E; Feigenson, G W (1990) Thermodynamics of mixing of phosphatidylserine/phosphatidylcholine from measurements of high-affinity calcium binding. Biochemistry 29:8291-7
Yeager, M D; Feigenson, G W (1990) Fluorescence quenching in model membranes: phospholipid acyl chain distributions around small fluorophores. Biochemistry 29:4380-92
Caffrey, M (1989) A lyotrope gradient method for liquid crystal temperature-composition-mesomorph diagram construction using time-resolved x-ray diffraction. Biophys J 55:47-52
Caffrey, M (1989) The study of lipid phase transition kinetics by time-resolved X-ray diffraction. Annu Rev Biophys Biophys Chem 18:159-86

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