This proposal describes a new family of small synthetic amphiphiles that are intended to promote three-dimensional crystallization of intrinsic membrane proteins. Membrane protein crystallization is necessary for high-resolution structural analysis, which, in turn, is essential for understanding protein function. Only about two dozen membrane protein crystal structures have been solved to date, and the rate-limiting step in structural analysis appears to be crystallization. Thus, if we are able to increase the number of membrane proteins that can be structurally analyzed, this research will have a profound effect on structural biology. Membrane proteins are solubilized, and therefore crystallized, as protein-detergent complexes. Conventional detergents are very flexible molecules; our hypothesis is that this flexibility disfavors growth of crystals containing detergents. We seek to replace conventional detergents with more rigid molecules that we call """"""""tripod amphiphiles."""""""" Tripod amphiphiles contain a tetrasubstituted carbon atom that bears three hydrophobic appendages and one hydrophilic appendage. These amphilphiles are synthesized by an efficient and general route, which makes it easy to explore the effects of incremental changes in amphiphile structure. Our efforts are focused on crystallizing three intrinsic membrane proteins, bacteriorhodopson and sensory rhodopsin-I from Halobacterium salinarium, and bovine rhodopsin, all of which are readily available to us.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Exploratory/Developmental Grants (R21)
Project #
1R21GM059351-01
Application #
2834134
Study Section
Bio-Organic and Natural Products Chemistry Study Section (BNP)
Project Start
1999-04-01
Project End
2001-03-31
Budget Start
1999-04-01
Budget End
2000-03-31
Support Year
1
Fiscal Year
1999
Total Cost
Indirect Cost
Name
University of Wisconsin Madison
Department
Chemistry
Type
Schools of Arts and Sciences
DUNS #
161202122
City
Madison
State
WI
Country
United States
Zip Code
53715
Yu, S M; McQuade, D T; Quinn, M A et al. (2000) An improved tripod amphiphile for membrane protein solubilization. Protein Sci 9:2518-27