Magnetically Aligned Membrane Model Systems with Positive Order Parameter:  Switching the Sign of Szz with Paramagnetic Ions

Prosser, R. Scott; Hunt, Sheri A.; DiNatale, and John A.; Vold, Regitze R.

doi:10.1021/ja953598x

Cited by 193 publications

(202 citation statements)

References 15 publications

Supporting

Mentioning

195

Contrasting

Order By: Relevance

“…For instance, if ⌬ is negative for the first group of lanthanide compounds, ⌬ is positive for the second group and vice versa. All experimental results obtained for lanthanide-containing liquid crystals 13,14 and for phospholipid bilayers [15][16][17][18][19] doped with lanthanide chelates are in agreement with a negative ⌬ value for the first group and a positive ⌬ value for the second group. But as we will show further in this paper, the reverse situation can be expected too.…”

Section: Introductionsupporting

confidence: 80%

On the magnetic anisotropy of lanthanide-containing metallomesogens

Mironov

Galyametdinov

Ceulemans

et al. 2000

The Journal of Chemical Physics

View full text Add to dashboard Cite

A general theoretical model of the origin of the magnetic anisotropy in paramagnetic metal-containing liquid crystals is developed. General relations between the molecular magnetic anisotropy of mesogenic lanthanide complexes and the macroscopic magnetic anisotropy of these liquid crystals in the mesophase are obtained. The net magnetic anisotropy of a real metallomesogen is shown to be the result of a complex interplay between the molecular magnetic anisotropy, orientation of the long molecular axis, and disorder effects. The sign of the magnetic anisotropy ⌬ depends not only on the anisotropy of the tensor of molecular magnetic susceptibility, but also on the orientation of the long molecular axis of rodlike lanthanide complexes with respect to the principal magnetic axes of the molecular tensor of magnetic susceptibility. The influence of microand macroscopic disorder in real liquid crystals is discussed. Numerical parametric calculations were used to rationalize the variation of the magnitude and sign of the magnetic anisotropy in a series of isostructural lanthanide-containing metallomesogens. Experimental magnetic susceptibility and magnetic anisotropy of a series of ͓Ln͑LH͒ 3 ͑NO 3 ͒ 3 ͔ compounds ͑LH is a Schiff base͒ are well reproduced by calculations based on the present model. Limitations of the Bleaney theory of magnetic anisotropy are analyzed.

show abstract

Section: Introductionsupporting

confidence: 80%

On the magnetic anisotropy of lanthanide-containing metallomesogens

Mironov

Galyametdinov

Ceulemans

et al. 2000

The Journal of Chemical Physics

View full text Add to dashboard Cite

show abstract

“…No structural information is available on these time scales for sites with isotropic resonances, for example the Nand C-terminal residues, because of the effects of complete motional averaging. However, it is possible to obtain crucial details about structure and dynamics of sites with limited motional averaging, whether due to local segmental or residue motions or because the sample itself undergoes some motions as seen in magnetically oriented bicelles (15)(16)(17).…”

Section: Resultsmentioning

confidence: 99%

“…When the direction of molecular orientation is parallel to that of the applied magnetic field, the resulting spectra are characterized by single line resonances in all frequency dimensions (13). Both mechanically (14) and magnetically (15)(16)(17) oriented samples of membrane proteins in phospholipid bilayers are ideal for this approach. Because the observed resonance frequencies depend on the orientations of the molecular sites relative to the axis of orientation, they provide the basis for a method of structure determination.…”

mentioning

confidence: 99%

Complete resolution of the solid-state NMR spectrum of a uniformly ¹⁵ N-labeled membrane protein in phospholipid bilayers

Marassi

Ramamoorthy

Opella

1997

Proc. Natl. Acad. Sci. U.S.A.

202

180

View full text Add to dashboard Cite

show abstract

“…Bilayers can be completely aligned between glass plates, and the resulting spectra from the incorporated proteins have line widths that are similar to those of single crystals [70]. Bicelles, prepared by mixing long chain and short chain lipids, can be aligned magnetically perpendicular to the direction to the magnetic field, or flipped to the parallel orientation by the addition of lanthanide ions [71], and have been used recently to obtain high-resolution spectra of membrane proteins [72].…”

Section: Sample Preparation-bilayersmentioning

confidence: 99%

NMR of membrane proteins in micelles and bilayers: The FXYD family proteins

Franzin

Gong

Thai

et al. 2007

Methods

View full text Add to dashboard Cite

Determining the atomic resolution structures of membrane proteins is of particular interest in contemporary structural biology. Helical membrane proteins constitute one-third of the expressed proteins encoded in a genome, many drugs have membrane-bound proteins as their receptors, and mutations in membrane proteins result in human diseases. Although integral membrane proteins provide daunting technical challenges for all methods of protein structure determination, nuclear magnetic resonance (NMR) spectroscopy can be an extremely versatile and powerful method for determining their structures and characterizing their dynamics, in lipid environments that closely mimic the cell membranes. Once milligram amounts of isotopically labeled protein are expressed and purified, micelle samples can be prepared for solution NMR analysis, and lipid bilayer samples can be prepared for solid-state NMR analysis. The two approaches are complementary and can provide detailed structural and dynamic information. This paper describes the steps for membrane protein structure determination using solution and solid-state NMR. The methods for protein expression and purification, sample preparation and NMR experiments are described and illustrated with examples from the FXYD proteins, a family of regulatory subunits of the Na, KATPase.

show abstract

Magnetically Aligned Membrane Model Systems with Positive Order Parameter: Switching the Sign of S_z_z with Paramagnetic Ions

Cited by 193 publications

References 15 publications

On the magnetic anisotropy of lanthanide-containing metallomesogens

On the magnetic anisotropy of lanthanide-containing metallomesogens

Complete resolution of the solid-state NMR spectrum of a uniformly ¹⁵ N-labeled membrane protein in phospholipid bilayers

NMR of membrane proteins in micelles and bilayers: The FXYD family proteins

Contact Info

Product

Resources

About

Magnetically Aligned Membrane Model Systems with Positive Order Parameter: Switching the Sign of Szz with Paramagnetic Ions

Cited by 193 publications

References 15 publications

On the magnetic anisotropy of lanthanide-containing metallomesogens

On the magnetic anisotropy of lanthanide-containing metallomesogens

Complete resolution of the solid-state NMR spectrum of a uniformly 15 N-labeled membrane protein in phospholipid bilayers

NMR of membrane proteins in micelles and bilayers: The FXYD family proteins

Contact Info

Product

Resources

About

Magnetically Aligned Membrane Model Systems with Positive Order Parameter: Switching the Sign of S_z_z with Paramagnetic Ions

Complete resolution of the solid-state NMR spectrum of a uniformly ¹⁵ N-labeled membrane protein in phospholipid bilayers