High-resolution NMR studies of encapsulated proteins in liquid ethane.
J Am Chem Soc. 2005 Jul 27;127(29):10176-7
Authors: Peterson RW, Lefebvre BG, Wand AJ
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.
High dimensional and high resolution pulse sequences for backbone resonance assignment of intrinsically disordered proteins
High dimensional and high resolution pulse sequences for backbone resonance assignment of intrinsically disordered proteins
Abstract Four novel 5D (HACA(N)CONH, HNCOCACB, (HACA)CON(CA)CONH, (H)NCO(NCA)CONH), and one 6D ((H)NCO(N)CACONH) NMR pulse sequences are proposed. The new experiments employ non-uniform sampling that enables achieving high resolution in indirectly detected dimensions. The experiments facilitate resonance assignment of intrinsically disordered proteins. The novel pulse sequences were successfully tested using δ subunit (20 kDa) of Bacillus subtilis RNA polymerase...
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02-21-2012 03:40 AM
Modification of Encapsulation Pressure of Reverse Micelles in Liquid Ethane
Modification of Encapsulation Pressure of Reverse Micelles in Liquid Ethane
Publication year: 2011
Source: Journal of Magnetic Resonance, In Press, Accepted Manuscript, Available online 20 June 2011</br>
Ronald W., Peterson , Nathaniel V., Nucci , A., Joshua Wand</br>
A central motivation for employing samples of encapsulated proteins dissolved in low viscosity fluids for high resolution NMR spectroscopy is to benefit from the superior performance afforded by the faster macromolecular rotation of the encapsulated protein than it has in free aqueous solution. Encapsulation of...
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06-22-2011 03:40 AM
High resolution NMR spectroscopy of nanocrystalline proteins at ultra-high magnetic field
High resolution NMR spectroscopy of nanocrystalline proteins at ultra-high magnetic field
Abstract Magic-angle spinning (MAS) solid-state NMR (SSNMR) spectroscopy of uniformly-13C,15N labeled protein samples provides insight into atomic-resolution chemistry and structure. Data collection efficiency has advanced remarkably in the last decade; however, the study of larger proteins is still challenged by relatively low resolution in comparison to solution NMR. In this study, we present a systematic analysis of SSNMR protein spectra acquired at 11.7, 17.6 and 21.1 Tesla (1H frequencies of...
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01-09-2011 12:46 PM
[NMR paper] High-resolution NMR spectroscopy of membrane proteins in aligned bicelles.
High-resolution NMR spectroscopy of membrane proteins in aligned bicelles.
Related Articles High-resolution NMR spectroscopy of membrane proteins in aligned bicelles.
J Am Chem Soc. 2004 Dec 1;126(47):15340-1
Authors: De Angelis AA, Nevzorov AA, Park SH, Howell SC, Mrse AA, Opella SJ
High-resolution solid-state NMR spectra can be obtained from uniformly (15)N-labeled membrane proteins in magnetically aligned bicelles. Fast uniaxial diffusion about the axis of the bilayer normal results in single-line spectra that contain the orientational...
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11-24-2010 10:03 PM
[NMR paper] A simple and effective NMR cell for studies of encapsulated proteins dissolved in low
A simple and effective NMR cell for studies of encapsulated proteins dissolved in low viscosity solvents.
Related Articles A simple and effective NMR cell for studies of encapsulated proteins dissolved in low viscosity solvents.
J Biomol NMR. 2002 Aug;23(4):311-6
Authors: Flynn PF, Milton MJ, Babu CR, Wand AJ
Application of triple-resonance and isotope-edited-NOE methods to the study of increasingly larger macromolecules and their complexes remains a central goal of solution NMR spectroscopy. The slow reorientational motion of larger molecules...
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11-24-2010 08:58 PM
[NMR paper] Controlling residual dipolar couplings in high-resolution NMR of proteins by strain i
Controlling residual dipolar couplings in high-resolution NMR of proteins by strain induced alignment in a gel.
Related Articles Controlling residual dipolar couplings in high-resolution NMR of proteins by strain induced alignment in a gel.
J Biomol NMR. 2001 Oct;21(2):141-51
Authors: Ishii Y, Markus MA, Tycko R
Water-soluble biological macromolecules can be weakly aligned by dissolution in a strained, hydrated gel such as cross-linked polyacrylamide, an effect termed 'strain-induced alignment in a gel' (SAG). SAG induces nonzero nuclear...
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11-19-2010 08:44 PM
[NMR paper] High-resolution NMR of encapsulated proteins dissolved in low-viscosity fluids.
High-resolution NMR of encapsulated proteins dissolved in low-viscosity fluids.
Related Articles High-resolution NMR of encapsulated proteins dissolved in low-viscosity fluids.
Proc Natl Acad Sci U S A. 1998 Dec 22;95(26):15299-302
Authors: Wand AJ, Ehrhardt MR, Flynn PF
The majority of known proteins are too large to be comprehensively examined by solution NMR methods, primarily because they tumble too slowly in solution. Here we introduce an approach to making the NMR relaxation properties of large proteins amenable to modern solution NMR...
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11-17-2010 11:15 PM
[NMR paper] High-resolution heteronuclear NMR of human ubiquitin in an aqueous liquid crystalline
High-resolution heteronuclear NMR of human ubiquitin in an aqueous liquid crystalline medium.
Related Articles High-resolution heteronuclear NMR of human ubiquitin in an aqueous liquid crystalline medium.
J Biomol NMR. 1997 Oct;10(3):289-92
Authors: Bax A, Tjandra N
A mixture of dihexanoyl phosphatidylcholine and dimyristoyl phosphatidylcholine in water forms disc-shaped particles, often referred to as bicelles . These adopt an ordered, liquid crystalline phase, which can be maintained at very low concentrations of the bicelles (down to 3%...