scholarly journals Effect of red blood cell shape changes on haemoglobin interactions and dynamics: a neutron scattering study

2020 ◽  
Vol 7 (10) ◽  
pp. 201507
Author(s):  
Keyun Shou ◽  
Mona Sarter ◽  
Nicolas R. de Souza ◽  
Liliana de Campo ◽  
Andrew E. Whitten ◽  
...  
Keyword(s):  
Blood Cell ◽  
Neutron Scattering ◽  
Protein Interactions ◽  
Red Blood Cell ◽  
Small Angle ◽  
Time Scale ◽  
Small Angle Neutron Scattering ◽  
Length Scale ◽  
Elastic Neutron ◽  
Shape Changes

By using a combination of experimental neutron scattering techniques, it is possible to obtain a statistical perspective on red blood cell (RBC) shape in suspensions, and the inter-relationship with protein interactions and dynamics inside the confinement of the cell membrane. In this study, we examined the ultrastructure of RBC and protein–protein interactions of haemoglobin (Hb) in them using ultra-small-angle neutron scattering and small-angle neutron scattering (SANS). In addition, we used the neutron backscattering method to access Hb motion on the ns time scale and Å length scale. Quasi-elastic neutron scattering (QENS) experiments were performed to measure diffusive motion of Hb in RBCs and in an RBC lysate. By using QENS, we probed both internal Hb dynamics and global protein diffusion, on the accessible time scale and length scale by QENS. Shape changes of RBCs and variation of intracellular Hb concentration were induced by addition of the Na + -selective ionophore monensin and the K + -selective one, valinomycin. The experimental SANS and QENS results are discussed within the framework of crowded protein solutions, where free motion of Hb is obstructed by mutual interactions.

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.

On the Guinier law for spin-echo small-angle neutron scattering

2005 ◽  
Vol 38 (2) ◽  
pp. 340-345
Author(s):  
Håkon Kaya
Keyword(s):  
Neutron Scattering ◽  
Autocorrelation Function ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Spin Echo ◽  
Radius Of Gyration ◽  
Length Scale ◽  
Average Width ◽  
Guinier Analysis ◽  
Guinier Law

It is shown that Guinier analysis of spin-echo small-angle neutron scattering (SESANS) data is dependent on the instrumental setup, in particular the range of scattering vectors accessible by the detector. In the case that Guinier analysis is permissible, the length scale obtained is proportional to the average width of the density autocorrelation function of the scattering particle, and not its radius of gyration.

Sign in / Sign up

Export Citation Format

Share Document