Response to “Reply to the ‘Comment on “Cholesterol Solubility Limit in Lipid Membranes probed by Small Angle Neutron Scattering and MD Simulations by Ursula Perez-Salas, Soft Matter, 2014, 10, 9313–9317”’”

Soft Matter ◽  
2015 ◽  
Vol 11 (38) ◽  
pp. 7457-7457
Author(s):  
Richard M. Epand ◽  
Diana Bach ◽  
Ellen Wachtel
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Lipid Membranes ◽  
Small Angle Neutron Scattering ◽  
Soft Matter ◽  
Md Simulations ◽  
Solubility Limit ◽  
Cholesterol Solubility

As authors of the “Comment on ‘Cholesterol solubility limit in lipid membranes probed by small angle neutron scattering and MD simulations’”, we wish to comment on both the form and content of the Reply cited above.

Comment on “Cholesterol solubility limit in lipid membranes probed by small angle neutron scattering and MD simulations” by S. Garg et al., Soft Matter, 2014, 10, 9313

Soft Matter ◽  
2015 ◽  
Vol 11 (27) ◽  
pp. 5580-5581
Author(s):  
Richard M. Epand ◽  
Diana Bach ◽  
Ellen Wachtel
Keyword(s):  
Phase Separation ◽  
Neutron Scattering ◽  
Small Angle ◽  
Lipid Membranes ◽  
Small Angle Neutron Scattering ◽  
Soft Matter ◽  
Md Simulations ◽  
Solubility Limit ◽  
Phospholipid Bilayers ◽  
Cholesterol Solubility

As consistently described in the literature, the solubility limit of cholesterol in phospholipid bilayers is defined by its phase separation and crystallization.

Reply to the ‘Comment on “Cholesterol Solubility Limit in Lipid Membranes probed by Small Angle Neutron Scattering and MD simulations”’ by R. Epand, Soft Matter, 2015, 11, DOI: 10.1039/C4SM02819H

Soft Matter ◽  
2015 ◽  
Vol 11 (27) ◽  
pp. 5582-5584 ◽  
Author(s):  
Natalie Krzyzanowski ◽  
Lionel Porcar ◽  
Sumit Garg ◽  
Paul Butler ◽  
Francisco Castro-Roman ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Lipid Membranes ◽  
Small Angle Neutron Scattering ◽  
Soft Matter ◽  
Recent Article ◽  
Md Simulations ◽  
Solubility Limit ◽  
Cholesterol Solubility

In the comment by Epand et al. on our recent article, it is stated that the term “cholesterol solubility limit” is misused.

Cholesterol solubility limit in lipid membranes probed by small angle neutron scattering and MD simulations

Soft Matter ◽  
2014 ◽  
Vol 10 (46) ◽  
pp. 9313-9317 ◽  
Author(s):  
Sumit Garg ◽  
Francisco Castro-Roman ◽  
Lionel Porcar ◽  
Paul Butler ◽  
Pedro Jesus Bautista ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Neutron Scattering ◽  
Small Angle ◽  
Lipid Membranes ◽  
Small Angle Neutron Scattering ◽  
Md Simulations ◽  
Solubility Limit ◽  
Coarse Grained ◽  
Small Unilamellar Vesicles ◽  
Cholesterol Solubility

The solubility limits of cholesterol in small unilamellar vesicles made of POPS and POPC were probed using Small Angle Neutron Scattering (SANS) and coarse grained (CG) molecular dynamics (MD) simulations.

Small-Angle Neutron Scattering of Bilayer Vesicles Made with Synthetic Phospholipids

1998 ◽  
Vol 550 ◽  
Author(s):  
S. F. Trevino ◽  
Robert lvkov ◽  
Gary R. Matyas ◽  
Frank J. Lebeda
Keyword(s):  
Neutron Scattering ◽  
Lipid Bilayers ◽  
Small Angle ◽  
Lipid Membranes ◽  
Small Angle Neutron Scattering ◽  
Bilayer Lipid Membranes ◽  
Lipid Concentration ◽  
The Core ◽  
Delivery Vehicles ◽  
Therapeutic Compounds

AbstractWe have used Small-Angle Neutron Scattering to investigate the structure of bilayer lipid membranes in aqueous solution. The lipids consist of equimolar concentrations of two molecules DMPG and DMPC (see text). The structures consist of solvent filled cores surrounded by shells composed of the lipid bilayers. In particular the radii of the core and shell thickness are measured as a function of lipid concentration and temperature. Other features which reveal themselves are vesicle forming ability of the lipids, additional larger structures and inter-vesicle interactions at large vesicle concentrations. The study is motivated by the possible use of these systems as delivery vehicles for various beneficial therapeutic compounds.

scholarly journals Flexible Sample Environment for the Investigation of Soft Matter at the European Spallation Source: Part II—The GISANS Setup

2021 ◽  
Vol 11 (9) ◽  
pp. 4036
Author(s):  
Tobias Widmann ◽  
Lucas P. Kreuzer ◽  
Matthias Kühnhammer ◽  
Andreas J. Schmid ◽  
Lars Wiehemeier ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Soft Matter ◽  
Gas Flow ◽  
Ambient Conditions ◽  
Experimental Conditions ◽  
Solvent Vapor ◽  
Spallation Source ◽  
Sample Environment

The FlexiProb project is a joint effort of three soft matter groups at the Universities of Bielefeld, Darmstadt, and Munich with scientific support from the European Spallation Source (ESS), the small-K advanced diffractometer (SKADI) beamline development group of the Jülich Centre for Neutron Science (JCNS), and the Heinz Maier-Leibnitz Zentrum (MLZ). Within this framework, a flexible and quickly interchangeable sample carrier system for small-angle neutron scattering (SANS) at the ESS was developed. In the present contribution, the development of a sample environment for the investigation of soft matter thin films with grazing-incidence small-angle neutron scattering (GISANS) is introduced. Therefore, components were assembled on an optical breadboard for the measurement of thin film samples under controlled ambient conditions, with adjustable temperature and humidity, as well as the optional in situ recording of the film thickness via spectral reflectance. Samples were placed in a 3D-printed spherical humidity metal chamber, which enabled the accurate control of experimental conditions via water-heated channels within its walls. A separately heated gas flow stream supplied an adjustable flow of dry or saturated solvent vapor. First test experiments proved the concept of the setup and respective component functionality.

scholarly journals Soft Matter Sample Environments for Time-Resolved Small Angle Neutron Scattering Experiments: A Review

2021 ◽  
Vol 11 (12) ◽  
pp. 5566
Author(s):  
Volker S. Urban ◽  
William T. Heller ◽  
John Katsaras ◽  
Wim Bras
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
High Intensity ◽  
Small Angle Neutron Scattering ◽  
Soft Matter ◽  
Condensed Matter ◽  
Large Body ◽  
Soft Condensed Matter ◽  
Time Resolved ◽  
Neutron Sources

With the promise of new, more powerful neutron sources in the future, the possibilities for time-resolved neutron scattering experiments will improve and are bound to gain in interest. While there is already a large body of work on the accurate control of temperature, pressure, and magnetic fields for static experiments, this field is less well developed for time-resolved experiments on soft condensed matter and biomaterials. We present here an overview of different sample environments and technique combinations that have been developed so far and which might inspire further developments so that one can take full advantage of both the existing facilities as well as the possibilities that future high intensity neutron sources will offer.

scholarly journals The basics of small-angle neutron scattering (SANS for new users of structural biology)

2020 ◽  
Vol 236 ◽  
pp. 03001
Author(s):  
Cy M. Jeffries ◽  
Zuzanna Pietras ◽  
Dmitri I. Svergun
Keyword(s):  
Neutron Scattering ◽  
Structural Biology ◽  
Small Angle ◽  
Structural State ◽  
Small Angle Neutron Scattering ◽  
Soft Matter ◽  
Higher Order ◽  
Hydrogen Interaction ◽  
The Way

Small-angle neutron scattering (SANS) provides a means to probe the time-preserved structural state(s) of bio-macromolecules in solution. As such, SANS affords the opportunity to assess the redistribution of mass, i.e., changes in conformation, which occur when macromolecules interact to form higher-order assemblies and to evaluate the structure and disposition of components within such systems. As a technique, SANS offers scope for ‘out of the box thinking’, from simply investigating the structures of macromolecules and their complexes through to where structural biology interfaces with soft-matter and nanotechnology. All of this simply rests on the way neutrons interact and scatter from atoms (largely hydrogens) and how this interaction differs from the scattering of neutrons from the nuclei of other ‘biological isotopes’. The following chapter describes the basics of neutron scattering for new users of structural biology in context of the neutron/hydrogen interaction and how this can be exploited to interrogate the structures of macromolecules, their complexes and nano-conjugates in solution.

Small-angle neutron scattering and the errors in protein structures that arise from uncorrected background and intermolecular interactions

2008 ◽  
Vol 41 (2) ◽  
pp. 456-465 ◽  
Author(s):  
Kenneth A. Rubinson ◽  
Christopher Stanley ◽  
Susan Krueger
Keyword(s):  
Neutron Scattering ◽  
Intermolecular Interactions ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Soft Matter ◽  
Protein Structures ◽  
Background Correction ◽  
Length Scale ◽  
Accuracy And Precision ◽  
Unique Method

Small-angle neutron scattering (SANS) provides a unique method to probe soft matter in the 10–100 nm length scale in solutions. In order to determine the shape and size of biological macromolecular structures correctly with SANS, a background-subtracted, undistorted scattering curve must be measured, and the required accuracy and precision is especially needed at the short-length-scale limit. A true scattering curve is also needed to discern whether intermolecular interactions are present, which also are probed in the SANS experiment. This article shows how to detect intermolecular interactions so that subsequent structure modeling can be performed using only data that do not contain such contributions. It is also shown how control of many factors can lead to an accurate baseline, or background, correction for scattering from proteins, especially to account for proton incoherent scattering. Failure to make this background correction properly from proteins, polymers, nucleic acids and lipids can result in incorrect values for the calculated shapes and sizes of the molecules as well as the derived magnitudes of the intermolecular interactions.

scholarly journals Deswelling of microfibril bundles in drying wood studied by small-angle neutron scattering and molecular dynamics

Cellulose ◽  
2021 ◽  
Author(s):  
Aleksi Zitting ◽  
Antti Paajanen ◽  
Lauri Rautkari ◽  
Paavo A. Penttilä
Keyword(s):  
Molecular Dynamics ◽  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Structural Changes ◽  
Md Simulations ◽  
Cellulose Microfibrils ◽  
Dynamic Vapor Sorption ◽  
Time Resolved ◽  
Constant Rate

Abstract Structural changes of cellulose microfibrils and microfibril bundles in unmodified spruce cell wall due to drying in air were investigated using time-resolved small-angle neutron scattering (SANS). The scattering analysis was supported with dynamic vapor sorption (DVS) measurements to quantify the macroscopic drying kinetics. Molecular dynamics (MD) simulations were carried out to aid in understanding the molecular-level wood-water interactions during drying. Both SANS experiments and simulations support the notion that individual cellulose microfibrils remain relatively unaffected by drying. There is, however, a significant decrease in fibril-to-fibril distances in microfibril bundles. Both scattering and DVS experiments showed two distinct drying regions: constant-rate drying and falling-rate drying. This was also supported by the MD simulation results. The shrinking of the fibril bundles starts at the boundary of these two regions, which is accompanied by a strong decrease in the diffusivity of water in between the microfibrils. Graphic abstract

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