NMR studies of complex surfactant systems

Söderman, Olle; Stilbs, Peter

doi:10.1016/0079-6565(94)80013-8

Cited by 317 publications

(226 citation statements)

References 164 publications

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“…The details of this method are beyond the scope of this article and the interested reader is referred to previously published reviews [13,28,31]. Here, only a brief introduction will be given.…”

Section: The Pfg-nmr Methods For Measuring Lipid Translational Diffusionmentioning

confidence: 99%

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Pfg NMR studies of lateral diffusion in oriented lipid bilayers

Orädd

Lindblom

2005

Spectroscopy

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Abstract. The pfg-NMR diffusion technique is proposed to have an appreciable potential for future biophysical investigations in the field of membrane biology. Topics like transport of molecules both across and in the plane of the membrane can be successfully studied, as well as the formation of lipid domains and their intrinsic dynamics can be scrutinized. This short review will introduce the fundamental aspects of orientation dependent NMR interactions and the technique of macroscopically oriented bilayers for eliminating the unwanted effects of those interactions. The pfg-NMR technique will be briefly introduced and finally, some recent results illustrating the potential of the method are presented. Orientation dependent NMR interactionsThe NMR spectrum for a general spin system is determined by the spin Hamiltonian, H, which consists of a number of interaction terms, of which the following four terms are of interest:where H Z is the Zeeman term and the next three terms represent the static interactions. The static interactions have a common scaling term, (1/2)(3 cos 2 θ − 1), which is the second Legendre polynomial, P 2 (θ), where θ is an angle that relates the principle coordinate system of the specific interaction to the main magnetic field (B 0 ) [12]. This will have the following effects on the observed NMR spectrum:-H CSA -The chemical shift anisotropy that represents the effect of induced magnetic fields due to orbital electronic motions, i.e. the chemical shift. Will change the chemical shift of the spectrum with a factor proportional to P 2 (θ). -H Q -The quadrupole interaction between the nuclear quadrupole moment and the surrounding electric field gradient. Will scale the quadrupolar coupling constant observed for nuclei with spin > 1/2 according to P 2 (θ). -H D -The dipolar interaction that represents the magnetic interaction between dipoles. Due to simultaneous coupling to several different dipoles this term will give rise to a linebroadening, which is proportional to P 2 (θ).For cos θ = 1/ √ 3, i.e. θ = 54.7 • , the scaling term (1/2)(3 cos 2 θ − 1) becomes zero and the static interactions "magically" disappear. This condition is generally hard to obtain since θ is distributed randomly in a non-oriented sample so one has to use special techniques in order to remove the static interactions. In the commonly used solid-state NMR technique, where magic angle spinning (MAS) is utilized, the sample is transferred into a rotor that can be spun at very high spinning rates. spinning of the sample causes all the static interactions to be projected onto the spinning axis of the rotor, which is then turned to the magic angle (54.7 • ) with respect to B 0 , thereby removing all the static interactions in the sample [16]. For liquid crystalline bilayers, on the other hand, the fast lateral reorientation and intermolecular rotation about the long axis of the molecules takes the role of the rotor and partially averages the interactions to leave only the part that is parallel to the normal with the bilayer. Thus...

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Section: The Pfg-nmr Methods For Measuring Lipid Translational Diffusionmentioning

confidence: 99%

“…One of the most successful applications of pfg-NMR is its use in extracting structural information about heterogeneous systems such as complex liquids and liquid crystals [13,28,31] and in special, the lipid lateral diffusion coefficients in a macroscopically oriented L α phase can be directly measured [13,14,20].…”

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confidence: 99%

Pfg NMR studies of lateral diffusion in oriented lipid bilayers

Orädd

Lindblom

2005

Spectroscopy

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“…When aqueous solutions of surfactants are analyzed, an equilibrium between surfactant monomers and micelles has to be considered (19,(22)(23)(24). It is therefore reasonable to express the self-diffusion coefficient at concentrations above the cmc as the concentration-weighted average coefficient of the fast diffusing monomers and the slow diffusing micelles, according to [2] where p mono and P mic are the molar fractions of the monomers and the micelles, respectively.…”

Section: Self-diffusion Coefficient For Single Surfactantmentioning

confidence: 99%

Investigation of the Interactions of Polyvinylpyrrolidone with Mixtures of Anionic and Nonionic Surfactants or Anionic and Zwitterionic Surfactants by Pulsed Field Gradient NMR

Misselyn-Bauduin

Thibaut

Grandjean

et al. 2001

Journal of Colloid and Interface Science

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The interaction of polyvinylpyrrolidone (PVP) with an anionic surfactant (sodium dodecyl sulfate, SDS), a nonionic surfactant (pentaethylene glycol monodecyl ether, C 10 E 5 ), and a zwitterionic surfactant (lauryl amido propyl betaine, LAPB) has been investigated by means of pulsed gradient spin-echo NMR (FT-PGSE NMR), allowing self-diffusion coefficients to be determined. The results confirm the strong interaction prevailing in the PVP/SDS system, whereas no association has been observed in the PVP/C 10 E 5 and PVP/LAPB systems. Mixing PVP with two surfactants, namely SDS and C 10 E 5 or SDS and LAPB, results in the formation of ternary aggregates between the polymer and the mixed micelles.

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“…Determination of Peptide Partition Coefficients from Diffusion Measurements-The NMR-based method used in this work to determine the partition coefficient of the peptides in micelles is similar to that described elsewhere (27)(28)(29)(30). In the present case, a pulsed field gradient longitudinal eddy-current delay experiment was used instead of the stimulated spin-echo experiment.…”

Section: Fig 2 Summary Of Nmr Data For E3-cyd In Water (A) and Micementioning

confidence: 99%

A Membrane Setting for the Sorting Motifs Present in the Adenovirus E3-13.7 Protein Which Down-regulates the Epidermal Growth Factor Receptor

Vinogradova

Carlin

Sönnichsen

et al. 1998

Journal of Biological Chemistry

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The adenovirus E3-13.7 protein interferes with endosomal protein sorting to down-regulate the epidermal growth factor receptor and related tyrosine kinase receptors. The cytoplasmic C terminus of this protein contains three protein sorting motifs which are related to the function of E3-13.7. In this study, the structure of a 23-residue polypeptide corresponding to this domain was examined using solution NMR and CD spectroscopic methods. The peptide was observed to exist in a mostly random structural state in aqueous solution but underwent high affinity association with dodecylphosphocholine micelles, where it adopted an ordered structure. The affinity of this peptide for the micellar surface and the structure of the bound peptide were independent of pH variation, surface charge, or attachment of a myristoyl anchor to the N-terminal. Studies with phospholipid vesicles suggested that the micellar structural results can be extrapolated to a true lipid bilayer. On the micellar surface all three sorting motifs are closely associated with the water/apolar interface: 72-YLRH and 87-LL lie within interfacial amphipathic helices, while 76-HPQY is non-helical and dimples just above the surface. These results contribute to the development of an understanding of the basis for specificity in recognition of sorting motifs by components of the cellular protein trafficking machinery.A 13.7-kDa protein expressed from the "Early 3" genome region of adenovirus (E3-13.7) down-regulates the EGFR 1 and related tyrosine kinase receptors during infection of epithelial cells and fibroblasts (1, 2). For EGFR it has been shown that E3-13.7 exerts its role by altering sorting at the endosomal level (3) such that the ratio of receptor destined for lysosomal degradation relative to receptor destined for recycling to the plasma membrane surface is increased. The down-regulatory action of E3-13.7 is believed to be associated with the constitutive recycling pathway of EGFR and does not require ligand stimulation of the receptor to be operative. An enhanced understanding of the down-regulatory mechanism of E3-13.7 is desirable because of light it will shed both upon the cell biology of protein trafficking pathways and upon the molecular biology of adenoviral infections.As outlined in Fig. 1, E3-13.7 is an integral membrane protein comprised of an N-terminal transmembrane helix followed by an extracellular/lumenal loop, a second transmembrane segment, and a C-terminal cytoplasmic domain (1). While the process by which E3-13.7 down-regulates tyrosine kinase receptors is incompletely understood, it is known that the Cterminal cytoplasmic domain (E3-CyD) is critical to its function. Within this 23-residue domain there are three different sequence motifs (Fig. 1) known to be broadly relevant to the cellular trafficking of membrane proteins via clathrin-mediated internalization pathways (4 -6). One of these is the "dileucine" (87-LL) motif (Refs. 7-9 and references therein). While a functional role for this motif in E3-13.7 has yet to be established, ...

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NMR studies of complex surfactant systems

Cited by 317 publications

References 164 publications

Pfg NMR studies of lateral diffusion in oriented lipid bilayers

Pfg NMR studies of lateral diffusion in oriented lipid bilayers

Investigation of the Interactions of Polyvinylpyrrolidone with Mixtures of Anionic and Nonionic Surfactants or Anionic and Zwitterionic Surfactants by Pulsed Field Gradient NMR

A Membrane Setting for the Sorting Motifs Present in the Adenovirus E3-13.7 Protein Which Down-regulates the Epidermal Growth Factor Receptor

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