High-pressure small-angle neutron scattering studies of glucose isomerase conformation in solution

Abstract

Synopsis Small-angle neutron scattering (SANS) studies of glucose/xylose isomerase indicate that the structure of this protein in solution is very stable and very similar to that in a crystal, in a broad pressure range up to 150 MPa.This enzyme can be used as a secondary standard for SANS measurements.Abstract Small-angle neutron scattering (SANS) of solutions of glucose/xylose isomerase from Streptomyces rubiginosus was measured as a function of pressure. We show that the solution structure of the enzyme as seen by SANS is practically the same as in the crystal and is not changing with pressure up to 150 MPa. This reflects the unusually high structural stability of this material, which makes it extremely interesting to use also as secondary standard for pressure dependent SANS experiments. This lack of pressure dependence of the SANS data indicates also that any possible change in hydration of the protein induced by pressure is not visible in the SANS curves. A proper correction procedure must be used for the SANS data in order to account for the distortion of the intensity curve due to the hard sphere and electrostatic interactions. After this correction isomerase, the enzyme of a high conformational stability, can be readily used as a secondary standard for SANS measurements. scattering standard; glucose/xylose isomerase; structure stability; Small Angle Neutron Scattering; high pressure; SANS

A high pressure cell for small angle neutron scattering up to 500MPa in combination with light scattering to investigate liquid samples

“…Clearly, b does not depend on P since it is entirely given by the atomic composition; also, V does not change much with P since the scattering curves show no change in shape. This finding is supported by recent SANS results on glucose isomerase, where the shape of the scattering curves did not also change with P. 25 Therefore, b / V is considered as being not pressure dependent, and, likewise, the structure factor at q = 0 which was calculated using a rescaled mean spherical approximation calculation is S͑q =0͒ = 0.68. 26 What differs is mainly the scattering length density 0 of the D 2 O, because the number density of scatterers depends on P. Following Eq.…”

SANS and dynamic light scattering to investigate the viscosity of toluene under high pressure up to 1800 bar

“…interpolating the values for all temperatures using a 2 The compressibility of the tracer particle can be an issue, but we have shown here that silica colloids hardly shrink and since pure silica can be nicely dispersed in water it can be a useful tracer also for biological systems. Also some proteins like for example glucose isomerase were found to be remarkably stable under high pressure conditions [19] and can thus serve as a perfect test particle for the determination of the pressure dependence of the solvent viscosity, which is in that case basically a water/buffer solution. So we are rather confident that not only hydrophobic organic solvents can be measured but likewise aqueous systems which play an important role in deep ocean research and related fields.…”

Biological small-angle neutron scattering: recent results and development

“…This is partly owing to the technical reason that pressure cells must be both robust and at the same time reasonably transparent to neutrons in order to preserve a good signal to noise from the enclosed, weakly scattering aqueous solution. A custom-made highpressure cell, using a sapphire window, allowed the conformational state and the hydration water of glucose/xylose isomerase to be probed under pressures of up to 150 MPa (Banachowicz et al, 2009). Other facilities have also recently introduced high-pressure cells for Bio-SANS (Heller et al, 2014).…”