Reverse micelle encapsulation of membrane-anchored proteins for solution NMR studies.
Perhaps 5%-10% of proteins bind to membranes via a covalently attached lipid. Posttranslational attachment of fatty acids such as myristate occurs on a variety of viral and cellular proteins. High-resolution information about the nature of lipidated proteins is remarkably sparse, often because of solubility problems caused by the exposed fatty acids. Reverse micelle encapsulation is used here to study two myristoylated proteins in their lipid-extruded states: myristoylated recoverin, which is a switch in the Ca(2+) signaling pathway in vision, and the myristoylated HIV-1 matrix protein, which is postulated to be targeted to the plasma membrane through its binding to phosphatidylinositol-4,5-bisphosphate. Both proteins have been successfully encapsulated in the lipid-extruded state and high-resolution NMR spectra obtained. Both proteins bind their activating ligands in the reverse micelle. This approach seems broadly applicable to membrane proteins with exposed fatty acid chains that have eluded structural characterization by conventional approaches.
Johnson Research Foundation and Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA 19104-6059, USA.
Kathleen G
KG
Valentine
Ronald W
RW
Peterson
Jamil S
JS
Saad
Michael F
MF
Summers
Xianzhong
X
Xu
James B
JB
Ames
A Joshua
AJ
Wand
D002214:Capsules / Q000737:chemistry; D005227:Fatty Acids / Q000737:chemistry; D015488:HIV Antigens / Q000032:analysis / Q000737:chemistry; D015497:HIV-1 / Q000737:chemistry; D008565:Membrane Proteins / Q000032:analysis* / Q000737:chemistry; D008823:Micelles; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D051603:Recoverin / Q000032:analysis / Q000737:chemistry; D012995:Solubility; D054301:gag Gene Products, Human Immunodeficiency Virus / Q000032:analysis / Q000737:chemistry
D002214:Capsules; D005227:Fatty Acids; D015488:HIV Antigens; D008565:Membrane Proteins; D008823:Micelles; D054301:gag Gene Products, Human Immunodeficiency Virus; C054858:p17 protein, Human Immunodeficiency Virus Type 1; D051603:Recoverin