Concentration Dependence of Radius of Gyration of Sodium Poly(styrenesulfonate) over a Wide Range of Concentration Studied by Small-Angle Neutron Scattering†

Langmuir ◽  
1999 ◽  
Vol 15 (12) ◽  
pp. 4120-4122 ◽  
Author(s):  
Yoshiaki Takahashi ◽  
Naoki Matsumoto ◽  
Shinji Iio ◽  
Hidemi Kondo ◽  
Ichiro Noda ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Concentration Dependence ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Radius Of Gyration ◽  
Wide Range

scholarly journals Structural aspects of human lactoferrin in the iron-binding process studied by molecular dynamics and small-angle neutron scattering

2018 ◽  
Vol 41 (9) ◽  
Author(s):  
Lilia Anghel ◽  
Aurel Radulescu ◽  
Raul Victor Erhan
Keyword(s):  
Molecular Dynamics ◽  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
The Body ◽  
Human Lactoferrin ◽  
Radius Of Gyration ◽  
Scattering Method ◽  
Iron Binding ◽  
Binding Process

Abstract. Lactoferrin is a non-heme protein known for its ability to bind tightly Fe(III) ions in various physiological environments. Due to this feature lactoferrin plays an important role in the processes of iron regulation at the cellular level preventing the body from damages produced by high levels of free iron ions. The X-ray crystal structure of human lactoferrin shows that the iron-binding process leads to conformational changes within the protein structure. The present study was addressed to conformation stability of human lactoferrin in solution. Using molecular dynamics simulations, it was shown that Arg121 is the key amino acid in the stabilization of the Fe(III) ion in the N-lobe of human lactoferrin. The small-angle neutron scattering method allowed us to detect the structural differences between the open and closed conformation of human lactoferrin in solution. Our results indicate that the radius of gyration of apolactoferrin appears to be smaller than that of the hololactoferrin, $R_{g}=24.16(\pm 0.707)$ R g = 24 . 16 ( ± 0 . 707 ) Å and $R_{g}= 26.20(\pm 1.191)$ R g = 26 . 20 ( ± 1 . 191 ) Å, respectively. The low-resolution three-dimensional models computed for both forms of human lactoferrin in solution also show visible differences, both having a more compact conformation compared to the high-resolution structure. Graphical abstract

Triple Isotopic Substitution Method in Small-Angle Neutron Scattering: Application to Some Problems of Structural Biology

1997 ◽  
Vol 30 (5) ◽  
pp. 787-791 ◽  
Author(s):  
I. N. Serdyuk ◽  
G. Zaccaï
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Structural Data ◽  
Necessary Condition ◽  
Isotopic Substitution ◽  
Deuterium Label ◽  
Geometrical Properties ◽  
Wide Range ◽  
Structural Methods

The triple isotopic substitution (TIS) method is based on the analysis of a scattering curve which is the difference between the scattering of two solutions containing appropriately deuterium-labelled particles. A necessary condition for the application of the method is that the two solutions are identical in all respects except for the extent of the deuterium label. Such an experimental scheme has allowed a number of unique physical experiments to be performed, the main ones being: (1) elimination of the contribution of the interparticle interference; (2) addition of both small- and large-sized foreign particles to those studied without distortions of the structural data; (3) highlighting of individual (quite small) regions in the molecules; (4) suppression of the dimerization contribution to the scattering curve. The application of this method is of special interest for studying the mutual three-dimensional disposition of individual small regions of molecules (3D mapping) and for investigating the geometrical properties of the surfaces of globular proteins. It is evident that TIS has a wide range of experimental possibilities, demonstrating that small-angle neutron scattering is one of the most informative structural methods for low resolution.

scholarly journals Open-Bundle Structure as the Unfolding Intermediate of Cytochrome c’ Revealed by Small Angle Neutron Scattering

2021 ◽  
Author(s):  
Takahide Yamaguchi ◽  
Kouhei Akao ◽  
Alexandros Koutsioubas ◽  
Henrich Frielinghaus ◽  
Takamitsu Kohzuma
Keyword(s):  
Cytochrome C ◽  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Alpha Helix ◽  
Random Coil ◽  
Radius Of Gyration ◽  
Alpha Helices ◽  
Cyt C ◽  
Bundle Structure

The open-bundle structure of cytochrome c’ as an unfolding intermediate was determined by small-angle neutron scattering experiment (SANS). The four-α-helix bundle structure of Cyt c’ at neutral pH was transited to an open-bundle structure (at pD ~13), which is a joint-clubs consisting of four clubs (α-helices) connected by short loops. The compactly folded structure of Cyt c’ (radius of gyration, Rg = 18 Å for the Cyt c’ dimer) at neutral or mildly alkaline pD transitioned to a remarkably larger “open-bundle” structure at pD ~13 (Rg = 25 Å for the Cyt c’ monomer). Cyt c’ adopts an unstructured random coil structure at pD = 1.7 (Rg = 25 Å for the Cyt c’ monomer). Numerical partial scattering function analysis (joint-clubs) and ab initio modelling gave structures similar to the “open-bundle”, which retains the α-helices but loses the bundle structure.

scholarly journals Small-angle neutron scattering studies suggest the mechanism of BinAB protein internalization

IUCrJ ◽  
2020 ◽  
Vol 7 (2) ◽  
pp. 166-172
Author(s):  
Mahima Sharma ◽  
Vinod K. Aswal ◽  
Vinay Kumar ◽  
R. Chidambaram
Keyword(s):  
Neutron Scattering ◽  
Conformational Changes ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Solution Structure ◽  
Expression System ◽  
Radius Of Gyration ◽  
Macromolecular Systems ◽  
Approaches To Study ◽  
Protein Components

Small-angle neutron scattering (SANS) is one of the most widely used neutron-based approaches to study the solution structure of biological macromolecular systems. The selective deuterium labelling of different protein components of a complex provides a means to probe conformational changes in multiprotein complexes. The Lysinibacillus sphaericus mosquito-larvicidal BinAB proteins exert toxicity through interaction with the receptor Cqm1 protein; however, the nature of the complex is not known. Rationally engineered deuterated BinB (dBinB) protein from the L. sphaericus ISPC-8 species was synthesized using an Escherichia coli-based protein-expression system in M9 medium in D2O for `contrast-matched' SANS experiments. SANS data were independently analysed by ab initio indirect Fourier transform-based modelling and using crystal structures. These studies confirm the dimeric status of Cqm1 in 100% D2O with a longest intramolecular vector (D max) of ∼94 Å and a radius of gyration (R g) of ∼31 Å. Notably, BinB binds to Cqm1, forming a heterodimeric complex (D max of ∼129 Å and R g of ∼40 Å) and alters its oligomeric status from a dimer to a monomer, as confirmed by matched-out Cqm1–dBinB (D max of ∼70 Å and R g of ∼22 Å). The present study thus provides the first insight into the events involved in the internalization of larvicidal proteins, likely by raft-dependent endocytosis.

Determination of Deuterium Incorporation into RNA and Protein Components of the Escherichia Coli Ribosome at Biosynthetic Deuteration by Small-Angle Neutron Scattering

1997 ◽  
Vol 30 (1) ◽  
pp. 59-64
Author(s):  
L. Fan ◽  
E. I. Zgurskaya ◽  
I. Shcherbakova ◽  
I. N. Serdyuk
Keyword(s):  
Escherichia Coli ◽  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Standard Procedure ◽  
Radius Of Gyration ◽  
Deuterium Incorporation ◽  
Simple Method ◽  
Protein Components

A simple method for the determination of deuterium incorporation into nonexchangeable (C-bonded) positions of RNA and protein components of the Escherichia coli ribosome at biosynthetic deuteration has been proposed using small-angle neutron scattering. The theory of the method is based on the joint use of two measurements: one of them is the dependence of neutron scattering intensity at zero angle on the contrast; the second is the dependence of the radius of gyration on the contrast. The main advantage of the method over the standard procedure is that it requires neither separation of the ribosome into RNA and protein components nor a subsequent time-consuming analysis of the hydrolysis products by nuclear magnetic resonance or mass spectrometry.

Performance and characteristics of the BILBY time-of-flight small-angle neutron scattering instrument

2019 ◽  
Vol 52 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Anna Sokolova ◽  
Andrew E. Whitten ◽  
Liliana de Campo ◽  
Jason Christoforidis ◽  
Andrew Eltobaji ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Materials Science ◽  
Time Of Flight ◽  
Nuclear Science ◽  
Scientific Disciplines ◽  
Wide Range ◽  
Wavelength Resolution ◽  
Reference Samples

BILBY is a recently constructed and commissioned time-of-flight small-angle neutron scattering instrument, operated by the Australian Centre for Neutron Scattering at the Australian Nuclear Science and Technology Organisation (ANSTO). BILBY provides a wide accessible q range (q ≃ 1.0 × 10−3 Å−1 to ∼1.8 Å−1) and variable wavelength resolution (Δλ/λ ≃ 3–30%) to complement the other small-angle and ultra-small-angle neutron scattering capabilities available at ANSTO. Since its construction, BILBY has been used to study samples from a wide range of scientific disciplines, including biology, chemistry, physics and materials science. This article describes the BILBY design and components, and shows data collected from a number of reference samples.

scholarly journals Open-Bundle Structure as the Unfolding Intermediate of Cytochrome c′ Revealed by Small Angle Neutron Scattering

Biomolecules ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 95
Author(s):  
Takahide Yamaguchi ◽  
Kouhei Akao ◽  
Alexandros Koutsioubas ◽  
Henrich Frielinghaus ◽  
Takamitsu Kohzuma
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Function Analysis ◽  
Dynamic Structure ◽  
Random Coil ◽  
Radius Of Gyration ◽  
Intermediate Structure ◽  
Cyt C ◽  
Bundle Structure

The dynamic structure changes, including the unfolding, dimerization, and transition from the compact to the open-bundle unfolding intermediate structure of Cyt c′, were detected by a small-angle neutron scattering experiment (SANS). The structure of Cyt c′ was changed into an unstructured random coil at pD = 1.7 (Rg = 25 Å for the Cyt c′ monomer). The four-α-helix bundle structure of Cyt c′ at neutral pH was transitioned to an open-bundle structure (at pD ~13), which is given by a numerical partial scattering function analysis as a joint-clubs model consisting of four clubs (α-helices) connected by short loops. The compactly folded structure of Cyt c′ (radius of gyration, Rg = 18 Å for the Cyt c′ dimer) at neutral or mildly alkaline pD transited to a remarkably larger open-bundle structure at pD ~13 (Rg = 25 Å for the Cyt c′ monomer). The open-bundle structure was also supported by ab initio modeling.

A Three-phase Model for the Structure of Porous Thin Films Determined by X-ray Reflectivity and Small-Angle Neutron Scattering

2000 ◽  
Vol 612 ◽  
Author(s):  
Wen-li Wu ◽  
Eric K. Lin ◽  
Changming Jin ◽  
Jeffrey T. Wetzel
Keyword(s):  
Thin Films ◽  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Coefficient Of Thermal Expansion ◽  
Average Pore Size ◽  
Silicon Substrates ◽  
Average Pore ◽  
X Ray ◽  
Wide Range

AbstractA methodology to characterize nanoporous thin films based on a novel combination of high-resolution specular x-ray reflectivity and small-angle neutron scattering has been advanced to accommodate heterogeneities within the material surrounding nanoscale voids. More specifically, the average pore size, pore connectivity, film thickness, wall or matrix density, coefficient of thermal expansion, and moisture uptake of nanoporous thin films with non-homogeneous solid matrices can be measured. The measurements can be performed directly on films up to 1.5 µm thick while supported on silicon substrates. This method has been successfully applied to a wide range of industrially developed materials for use as low-k interlayer dielectrics.

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