Friday, May 23, 2014

Optimized reverse micelle surfactant system for high-resolution NMR spectroscopy of encapsulated proteins and nucleic acids dissolved in low viscosity fluids


Recently the group of Joshua Wand has described the use of reverse micelles as a platform for DNP for solution-state NMR spectroscopy. Although this article is not directly related to DNP it gives more insight into the use of reverse micelles to obtain high resolution NMR spectra of large marcromolecules.



Dodevski, I., et al., Optimized reverse micelle surfactant system for high-resolution NMR spectroscopy of encapsulated proteins and nucleic acids dissolved in low viscosity fluids. J Am Chem Soc, 2014. 136(9): p. 3465-74.


An optimized reverse micelle surfactant system has been developed for solution nuclear magnetic resonance studies of encapsulated proteins and nucleic acids dissolved in low viscosity fluids. Comprising the nonionic 1-decanoyl-rac-glycerol and the zwitterionic lauryldimethylamine-N-oxide (10MAG/LDAO), this mixture is shown to efficiently encapsulate a diverse set of proteins and nucleic acids. Chemical shift analyses of these systems show that high structural fidelity is achieved upon encapsulation. The 10MAG/LDAO surfactant system reduces the molecular reorientation time for encapsulated macromolecules larger than ~20 kDa leading to improved overall NMR performance. The 10MAG/LDAO system can also be used for solution NMR studies of lipid-modified proteins. New and efficient strategies for optimization of encapsulation conditions are described. 10MAG/LDAO performs well in both the low viscosity pentane and ultralow viscosity liquid ethane and therefore will serve as a general surfactant system for initiating solution NMR studies of proteins and nucleic acids.