Stalk formation as a function of lipid composition studied by X-ray reflectivity

Khattari, Z. Y.; Köhler, Sebastian; Xu, Yuhang; Aeffner, Sebastian; Salditt, Tim

doi:10.1016/j.bbamem.2014.08.010

Cited by 15 publications

(22 citation statements)

References 60 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…polyethylene glycol (PEG) [26], introduces osmotic pressure to aqueous solution, and thus can mediate stalk formation [27] as well as full fusion [28] in pure lipid bilayers. Unfortunately, the osmotic pressure induced by PEG is rather weak [29,30] compared with the requirements of fusion in supported multibilayers [21,25]. In this chapter we first introduce basic principles of stalk formation in pure lipid bilayers, followed by the search for a "magic lipid mixture" which forms stalks at low osmotic pressure (high relative humidity), and finally the preliminary attempt to observe stalks in PEG solutions with the resulting "magic lipid mixture".…”

Section: Stalk Formation In Pure Lipid Bilayers In Aqueous Solutionsmentioning

confidence: 99%

“…The electron density ρ(z) along the membrane normal z can be calculated with F n derived above [25,68] with…”

Section: Electron Density Profile (Edp) Reconstructionmentioning

confidence: 99%

“…The decrease of P 0 and the increase of λ h imply that it is easier to dehydrate the bilayers when more DOPE is added. Note that P 0 and λ h of the same lipid mixture can sometimes vary dramatically between different measurements [21,25], due to various experimental conditions and fitting ranges. As sketched in Fig.…”

Section: Dopc-dopementioning

confidence: 99%

“…In this section, phase diagrams and hydration repulsion results of PC-PE-DOG, PC-PE-Chol and PC-PE-PIP 2 at various molar concentrations of the third lipid component will be presented. This part of data is published in [25], with the PC-PE-Chol data being re-measured. Fig.…”

Section: Ternary Lipid Mixturesmentioning

confidence: 99%

“…Fig. 1.6b demonstrates that the 2 nd Bragg intensity reaches the minimum at the RH* determined by GISAXS [25]. This way, we developed a more efficient approach to determine the RH* for L-R phase transition.…”

mentioning

confidence: 94%

See 4 more Smart Citations

Extending the x-ray study of membrane fusion in supported multibilayers towards physiological conditions

Xu¹

2017

Göttingen Series in X-Ray Physics

Self Cite

View full text Add to dashboard Cite

The Göttingen series in x-ray physics is intended as a collection of research monographs in x-ray science, carried out at the Institute for X-ray Physics at the Georg-August-Universität in Göttingen, and in the framework of its related research networks and collaborations. It covers topics ranging from x-ray microscopy, nano-focusing, wave propagation, image reconstruction, tomography, short x-ray pulses to applications of nanoscale x-ray imaging and biomolecular structure analysis. In most but not all cases, the contributions are based on Ph.D. dissertations. The individual monographs should be enhanced by putting them in the context of related work, often based on a common long term research strategy, and funded by the same research networks. We hope that the series will also help to enhance the visibility of the research carried out here and help others in the field to advance similar projects.

show abstract

Section: Stalk Formation In Pure Lipid Bilayers In Aqueous Solutionsmentioning

confidence: 99%

“…The electron density ρ(z) along the membrane normal z can be calculated with F n derived above [25,68] with…”

Section: Electron Density Profile (Edp) Reconstructionmentioning

confidence: 99%

Section: Dopc-dopementioning

confidence: 99%

Section: Ternary Lipid Mixturesmentioning

confidence: 99%

mentioning

confidence: 94%

See 3 more Smart Citations

Extending the x-ray study of membrane fusion in supported multibilayers towards physiological conditions

Xu¹

2017

Göttingen Series in X-Ray Physics

Self Cite

View full text Add to dashboard Cite

show abstract

A stalk fluid forming above the transition from the lamellar to the rhombohedral phase of lipid membranes

Scheu¹,

Komorowski²,

Shen³

et al. 2021

Eur Biophys J

Self Cite

View full text Add to dashboard Cite

In this work, we present evidence for the formation of transient stalks in aligned multilamellar stacks of lipid membranes. Just above the phase transition from the fluid ($$L_\alpha$$ L α ) lamellar phase to the rhombohedral phase (R), where lipid stalks crystallize on a super-lattice within the lipid bilayer stack, we observe a characteristic scattering pattern, which can be attributed to a correlated fluid of transient stalks. Excess (off-axis) diffuse scattering with a broad modulation around the position which later transforms to a sharp peak of the rhombohedral lattice, gives evidence for the stalk fluid forming as a pre-critical effect, reminiscent of critical phenomena in the vicinity of second-order phase transitions. Using high-resolution off-specular X-ray scattering and lineshape analysis we show that this pre-critical regime is accompanied by an anomalous elasticity behavior of the membrane stack, in particular an increase in inter-bilayer compressibility, i.e., a decrease in the compression modulus.

show abstract

Reconstitution of SNARE proteins into solid-supported lipid bilayer stacks and X-ray structure analysis

Kuhlmann

Brennich

et al. 2018

Biochimica et Biophysica Acta (BBA) - Biomembranes

Self Cite

View full text Add to dashboard Cite

SNAREs are known as an important family of proteins mediating vesicle fusion. For various biophysical studies, they have been reconstituted into supported single bilayers via proteoliposome adsorption and rupture. In this study we extended this method to the reconstitution of SNAREs into supported multilamellar lipid membranes, i.e. oriented multibilayer stacks, as an ideal model system for X-ray structure analysis (X-ray reflectivity and diffraction). The reconstitution was implemented through a pathway of proteomicelle, proteoliposome and multibilayer. To monitor the structural evolution in each step, we used small-angle X-ray scattering for the proteomicelles and proteoliposomes, followed by X-ray reflectivity and grazing-incidence small-angle scattering for the multibilayers. Results show that SNAREs can be successfully reconstituted into supported multibilayers, with high enough orientational alignment for the application of surface sensitive X-ray characterizations. Based on this protocol, we then investigated the effect of SNAREs on the structure and phase diagram of the lipid membranes. Beyond this application, this reconstitution protocol could also be useful for X-ray analysis of many further membrane proteins.

show abstract

Stalk formation as a function of lipid composition studied by X-ray reflectivity

Cited by 15 publications

References 60 publications

Extending the x-ray study of membrane fusion in supported multibilayers towards physiological conditions

Extending the x-ray study of membrane fusion in supported multibilayers towards physiological conditions

A stalk fluid forming above the transition from the lamellar to the rhombohedral phase of lipid membranes

Reconstitution of SNARE proteins into solid-supported lipid bilayer stacks and X-ray structure analysis

Contact Info

Product

Resources

About