The long-term goal of the proposed research is to understand the mechanisms of membrane fusion. I propose to develop a new system for measuring the forces involved in the early stages of fusion between two lipid bilayers using atomic force microscopy (AFM). The general strategy is to produce a lipid bilayer on a solid support and coat the tip of an AFM with a second lipid bilayer, bring the two bilayers together, and apply fore to the bilayer-bilayer contact until fusion is initiated. Preliminary experiments indicate that for certain lipids there is at least fusion of the outer leaflets, thus allowing the initial stages of fusion to be examined. This system will provide the basis for a long-term project to study the mechanisms of membrane fusion and the factors that control fusion.
The first aim of the research is to develop routine and robust methods for preparing lipid coated surfaces appropriate for the proposed experiments.
The second aim i s to demonstrate that membrane fusion between the outer leaflets occurs and measure the force associated with fusion.
The third aim i s to investigate the effect of geometry and strain on the force of fusion. In the long-term this system will allow mechanisms of fusion to be studied by varying a range of parameters such as lipid type, ionic conditions, temperature, and interaction geometry. It may also become possible to incorporate proteins that facilitate fusion into the system.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Postdoctoral Individual National Research Service Award (F32)
Project #
1F32GM020877-01
Application #
6298611
Study Section
Physical Biochemistry Study Section (PB)
Program Officer
Flicker, Paula F
Project Start
2001-02-01
Project End
Budget Start
2001-02-01
Budget End
2002-01-31
Support Year
1
Fiscal Year
2001
Total Cost
$33,260
Indirect Cost
Name
Johns Hopkins University
Department
Physiology
Type
Schools of Medicine
DUNS #
045911138
City
Baltimore
State
MD
Country
United States
Zip Code
21218
Singh, Sangita; Ballou, David P; Banerjee, Ruma (2011) Pre-steady-state kinetic analysis of enzyme-monitored turnover during cystathionine ?-synthase-catalyzed H(2)S generation. Biochemistry 50:419-25
Galinato, Mary Grace I; Spolitak, Tatyana; Ballou, David P et al. (2011) Elucidating the role of the proximal cysteine hydrogen-bonding network in ferric cytochrome P450cam and corresponding mutants using magnetic circular dichroism spectroscopy. Biochemistry 50:1053-69
Spolitak, Tatyana; Funhoff, Enrico G; Ballou, David P (2010) Spectroscopic studies of the oxidation of ferric CYP153A6 by peracids: Insights into P450 higher oxidation states. Arch Biochem Biophys 493:184-91
Mayfield, Jeffery A; Frederick, Rosanne E; Streit, Bennett R et al. (2010) Comprehensive spectroscopic, steady state, and transient kinetic studies of a representative siderophore-associated flavin monooxygenase. J Biol Chem 285:30375-88
Lee, Moon N; Takawira, Desire; Nikolova, Andriana P et al. (2009) Functional role for the conformationally mobile phenylalanine 223 in the reaction of methylenetetrahydrofolate reductase from Escherichia coli. Biochemistry 48:7673-85