High-resolution NMR studies of encapsulated proteins in liquid ethane.
Many of the difficulties presented by large, aggregation-prone, and membrane proteins to modern solution NMR spectroscopy can be alleviated by actively seeking to increase the effective rate of molecular reorientation. An emerging approach involves encapsulating the protein of interest within the protective shell of a reverse micelle and dissolving the resulting particle in a low viscosity fluid, such as the short chain alkanes. Here we present the encapsulation of proteins with high structural fidelity within reverse micelles dissolved in liquid ethane. The addition of appropriate cosurfactants can significantly reduce the pressure required for successful encapsulation. At these reduced pressures, the viscosity of the ethane solution is low enough to provide sufficiently rapid molecular reorientation to significantly lengthen the spin-spin NMR relaxation times of the encapsulated protein.
Peterson
Ronald W
RW
Johnson Research Foundation and Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6059, USA.
Lefebvre
Brian G
BG
Wand
A Joshua
AJ
D045304:Cytochromes c / Q000737:chemistry; D004980:Ethane / Q000737:chemistry*; D005418:Flavodoxin / Q000737:chemistry; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D011506:Proteins / Q000737:chemistry*; D025801:Ubiquitin / Q000737:chemistry; D014783:Viscosity
D005418:Flavodoxin; D011506:Proteins; D025801:Ubiquitin; D045304:Cytochromes c; D004980:Ethane