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Cryoprotectant‐free high‐pressure cooling and dynamic nuclear polarization for more sensitive detection of hydrogen in neutron protein crystallography
Author(s) -
Tanaka Ichiro,
Komatsuzaki Naoya,
Yue Wen-Xue,
Chatake Toshiyuki,
Kusaka Katsuhiro,
Niimura Nobuo,
Miura Daisuke,
Iwata Takahiro,
Miyachi Yoshiyuki,
Nukazuka Genki,
Matsuda Hiroki
Publication year - 2018
Publication title -
acta crystallographica section d
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.374
H-Index - 138
ISSN - 2059-7983
DOI - 10.1107/s2059798318005028
Subject(s) - polarization (electrochemistry) , neutron diffraction , crystallite , neutron , materials science , proton , analytical chemistry (journal) , cryoprotectant , chemistry , hydrogen , ambient pressure , crystallography , crystal structure , nuclear physics , chromatography , physics , thermodynamics , embryo , cryopreservation , biology , microbiology and biotechnology , organic chemistry
To improve the sensitivity of hydrogen detection using neutrons, a proton‐polarization technique together with a high‐pressure cooling method is necessary. The highest pressure (200 MPa) used in the experiment described here enabled relatively large protein crystals to be cooled without any cryoprotectants while retaining the protein structure, and it was confirmed that high‐pressure‐cooled crystals diffracted to nearly the same resolution as flash‐cooled small crystals soaked with cryoprotectants. Dynamic nuclear polarization was used as a proton‐polarization technique for protein crystals, and ∼300 mg polycrystalline protein doped with TEMPOL gave a maximum proton polarization of 22.3% at a temperature of 0.5 K in a 2.5 T magnetic field.