Abstract

The energetics governing the folding and function of membrane proteins is less well understood than for water-soluble ones. Thus, while there are abundant data concerning the free energy associated with the burial of an apolar group or the formation of a hydrogen bond in water-soluble proteins, such data are virtually non-existent for membrane proteins. We will determine how amino acid substitutions in the membrane protein bacteriorhodopsin affect its free energy of stabilization. It has been hypothesized that although water-soluble and membrane proteins differ greatly in the polarity of water-facing versus membrane lipid-facing residues, their interior side-chain packing and residue polarities are highly similar. To test this guiding hypothesis we will convert water-soluble proteins into membrane-soluble proteins and vice versa.
Our specific aims, then, are: - Aim 1. Membrane-soluble versions of the water-soluble coiled-coil peptide, GCN4-P1, will be designed, synthesized and characterized in micelles and bilayers. - Aim 2. We will determine the effect of amino acid substitutions on the thermodynamic stability of bacteriorhodopsin. - Aim 3. We will design and characterize a water-soluble version of phospholamban, a 57-residue membrane protein that forms transmembrane pentamers. In each case, the thermodynamic properties of the proteins will be thoroughly examined to provide a deeper, quantitative understanding of membrane protein structure.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM060610-04
Application #
6654926
Study Section
Biophysical Chemistry Study Section (BBCB)
Program Officer
Li, Jerry
Project Start
2000-09-30
Project End
2004-08-31
Budget Start
2003-09-01
Budget End
2004-08-31
Support Year
4
Fiscal Year
2003
Total Cost
$272,624
Indirect Cost

  Institution

Name
University of Pennsylvania
Department
Biochemistry
Type
Schools of Medicine
DUNS #
042250712
City
Philadelphia
State
PA
Country
United States
Zip Code
19104

  Publications

Shandler, Scott J; Korendovych, Ivan V; Moore, David T et al. (2011) Computational design of a ?-peptide that targets transmembrane helices. J Am Chem Soc 133:12378-81
Soto, Cinque S; Hannigan, Brett T; DeGrado, William F (2011) A photon-free approach to transmembrane protein structure determination. J Mol Biol 414:596-610
Remorino, Amanda; Korendovych, Ivan V; Wu, Yibing et al. (2011) Residue-specific vibrational echoes yield 3D structures of a transmembrane helix dimer. Science 332:1206-9
Zhu, Hua; Metcalf, Douglas G; Streu, Craig N et al. (2010) Specificity for homooligomer versus heterooligomer formation in integrin transmembrane helices. J Mol Biol 401:882-91
Goldberg, Shalom D; Clinthorne, Graham D; Goulian, Mark et al. (2010) Transmembrane polar interactions are required for signaling in the Escherichia coli sensor kinase PhoQ. Proc Natl Acad Sci U S A 107:8141-6
Berger, Bryan W; Kulp, Daniel W; Span, Lisa M et al. (2010) Consensus motif for integrin transmembrane helix association. Proc Natl Acad Sci U S A 107:703-8
Zhang, Yao; Kulp, Daniel W; Lear, James D et al. (2009) Experimental and computational evaluation of forces directing the association of transmembrane helices. J Am Chem Soc 131:11341-3
Weeks, Colin L; Polishchuk, Alexei; Getahun, Zelleka et al. (2008) Investigation of an unnatural amino acid for use as a resonance Raman probe: Detection limits, solvent and temperature dependence of the nuC identical withN band of 4-cyanophenylalanine. J Raman Spectrosc 39:1606-1613
Caputo, Gregory A; Litvinov, Rustem I; Li, Wei et al. (2008) Computationally designed peptide inhibitors of protein-protein interactions in membranes. Biochemistry 47:8600-6
Grigoryan, Gevorg; Degrado, William F (2008) Modest membrane hydrogen bonds deliver rich results. Nat Chem Biol 4:393-4

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