Data Collection for Dilute Protein Solutions via a Neutron Backscattering Spectrometer

Abstract

Understanding protein functions requires not only static but also dynamic structural information. Incoherent quasi-elastic neutron scattering (QENS), which utilizes the highly incoherent scattering ability of hydrogen, is a powerful technique for revealing the dynamics of proteins in deuterium oxide (D2O) buffer solutions. The background scattering of sample cells suitable for aqueous protein solution samples, conducted with a neutron backscattering spectrometer, was evaluated. It was found that the scattering intensity of an aluminum sample cell coated with boehmite using D2O was lower than that of a sample cell coated with regular water (H2O). The D2O-Boehmite coated cell was used for the QENS measurement of a 0.8 wt.% aqueous solution of an intrinsically disordered protein in an intrinsically disordered region of a helicase-associated endonuclease for a fork-structured type of DNA. The cell was inert against aqueous samples at 283–363 K. In addition, meticulous attention to cells with small individual weight differences and the positional reproducibility of the sample cell relative to the spectrometer neutron beam position enabled the accurate subtraction of the scattering profiles of the D2O buffer and the sample container. Consequently, high-quality information on protein dynamics could be extracted from dilute protein solutions.

Recent Progress on DNA ToF Backscattering Spectrometer in MLF, J-PARC

“…Including the sample cell for current and voltage application described above, we developed several sample cells such as standard aluminum cells for cooling and heating, quartz glass cell [9], single crystal sapphire cell, molybdenum cell for high temperature. We also investigated corrosion of aluminum cell by solution [10,11] and proposed surface treatment of aluminum cell adequate for some cases [12]. The details are shown in the references.…”