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Kitazato, Kohei*; Milliken, R. E.*; Iwata, Takahiro*; Abe, Masanao*; Otake, Makiko*; Matsuura, Shuji*; Takagi, Yasuhiko*; Nakamura, Tomoki*; Hiroi, Takahiro*; Matsuoka, Moe*; et al.
Nature Astronomy (Internet), 5(3), p.246 - 250, 2021/03
Times Cited Count：43 Percentile：96.93(Astronomy & Astrophysics)Here we report observations of Ryugu's subsurface material by the Near-Infrared Spectrometer (NIRS3) on the Hayabusa2 spacecraft. Reflectance spectra of excavated material exhibit a hydroxyl (OH) absorption feature that is slightly stronger and peak-shifted compared with that observed for the surface, indicating that space weathering and/or radiative heating have caused subtle spectral changes in the uppermost surface. However, the strength and shape of the OH feature still suggests that the subsurface material experienced heating above 300 
C, similar to the surface. In contrast, thermophysical modeling indicates that radiative heating does not increase the temperature above 200 C at the estimated excavation depth of 1 m, even if the semimajor axis is reduced to 0.344 au. This supports the hypothesis that primary thermal alteration occurred due to radiogenic and/or impact heating on Ryugu's parent body.
-glucosyltransferase from 
Hiromoto, Takeshi; Honjo, Eijiro*; Noda, Hisanobu*; Tamada, Taro; Kazuma, Kohei*; Suzuki, Masahiko*; Blaber, M.; Kuroki, Ryota
Protein Science, 24(3), p.395 - 407, 2015/03
Times Cited Count：62 Percentile：88.58(Biochemistry & Molecular Biology)UDP-glucose: anthocyanidin 3--glucosyltransferase (UGT78K6) from catalyzes the transfer of glucose from UDP-glucose to anthocyanidins such as delphinidin. To understand the acceptor-recognition scheme of UGT78K6, the crystal structure of UGT78K6 and its complex forms with anthocyanidin delphinidin and petunidin, and flavonol kaempferol were determined to resolutions of 1.85 
, 2.55 , 2.70 and 1.75 respectively. The anthocyanidin- and flavonol-acceptor binding details are almost identical in each complex structure, although the glucosylation activities against each acceptor were significantly different. The acceptor substrates in UGT78K6 are reversely bound to its binding site by a 180 rotation about the O1-O3 axis of the flavonoid backbones observed in 
GT1 and UGT78G1. These substrate recognition schemes suggest the potential for controlled synthesis of natural pigments.
-glucosyltransferase from Hiromoto, Takeshi; Honjo, Eijiro*; Tamada, Taro; Noda, Hisanobu*; Kazuma, Kohei*; Suzuki, Masahiko*; Kuroki, Ryota
Journal of Synchrotron Radiation, 20(6), p.894 - 898, 2013/11
Times Cited Count：38 Percentile：86.54(Instruments & Instrumentation)Flowers of the butterfly pea () accumulate a group of polyacylated anthocyanins, named ternatins, in their petals. The first step in ternatin biosynthesis is the transfer of glucose from UDP-glucose to anthocyanidins such as delphinidin, a reaction catalyzed in 
by UDP-glucose:anthocyanidin 3--glucosyltransferase (
3GT-A; AB185904). To elucidate the structure-function relationship of 3GT-A, recombinant 3GT-A was expressed in 
and its tertiary structure was determined to 1.85 , resolution by using X-ray crystallography. The structure of 3GT-A shows a common folding topology, the GT-B fold, comprised of two Rossmann-like 
/
/ domains and a cleft located between the N- and C-domains containing two cavities that are used as binding sites for the donor (UDP-Glc) and acceptor substrates. By comparing the structure of 3GT-A with that of the flavonoid glycosyltransferase GT1 from red grape (
) in complex with UDP-2-deoxy-2-fluoro glucose and kaempferol, locations of the catalytic His-Asp dyad and the residues involved in recognizing UDP-2-deoxy-2-fluoro glucose were essentially identical in 3GT-A, but certain residues of GT1 involved in binding kaempferol were found to be substituted in 3GT-A. These findings are important for understanding the differentiation of acceptor-substrate recognition in these two enzymes.
Y
MnO
Kajimoto, Ryoichi; Yokoo, Tetsuya*; Kofu, Maiko*; Noda, Kohei*; Kuwahara, Hideki*
Journal of Physics and Chemistry of Solids, 68(11), p.2087 - 2090, 2007/11
Times Cited Count：4 Percentile：22.69(Chemistry, Multidisciplinary)EuYMnO
shows an antiferromagnetic transition below 
K. A spontaneous ferroelectric polarization 
along 
appears below 
K. The direction of then switches to 
below 
K. To investigate the relation between and the magnetic structure (MS), we have performed a neutron diffraction study using EXCED diffractometer installed at KENS spallation neutron facility of KEK. Magnetic Bragg peaks with a wave vector (0,0.31,1) were observed. By comparing a magnetic Bragg peak whose scattering vector 
is almost parallel to 
and that with almost parallel to , we have succeeded in observing the change of the MS at the temperature (
) where appears and at where changes its polarization direction. Our observations can be interpreted as formation of a spiral spin structure and change of its easy plane in response to the change of the dielectric properties.
Daido, Hiroyuki; Sagisaka, Akito; Ogura, Koichi; Orimo, Satoshi; Nishiuchi, Mamiko; Yogo, Akifumi; Mori, Michiaki; Li, Z.*; Kiriyama, Hiromitsu; Kanazawa, Shuhei; et al.
X-Ray Lasers 2006; Springer Proceedings in Physics, Vol.115, p.595 - 605, 2007/00
At present, using ultra-short high intensity lasers at APRC, JAEA Kansai photon research institute, we are developing laser driven multiple quantum beams such as protons, X-rays, electrons and THz waves. These beams are perfectly synchronized with each other. The pulse duration of each beam is lass than a pico-second. They have sharp directionality with high brightness. If we properly combined these, we have new pump-probe techniques for various applications.
Al superconductors with Ta matrixTakeuchi, Takao*; Tagawa, Kohei*; Noda, Tetsuji*; Banno, Nobuya*; Iijima, Yasuo*; Kikuchi, Akihiro*; Kitaguchi, Hitoshi*; Kosuge, Michio*; Tsuchiya, Kiyosumi*; Koizumi, Norikiyo; et al.
IEEE Transactions on Applied Superconductivity, 16(2), p.1257 - 1260, 2006/06
Times Cited Count：6 Percentile：37.33(Engineering, Electrical & Electronic)Next generation nuclear fusion magnets would require a high-current conductor in fields more than 16 T. A CIC conductor of the rapid RHQT processed NbAl may be a promising candidate. Good deformability of intermediately-formed bcc supersaturated-solid solution indeed allowed fabricating such a CIC conductor, which would be subsequently transformation annealed. Ag has been internally included as a basic constituent of a round strand so far, because Ag is almost non-reactive with Nb matrix during the RHQ. However, both of Ag and Nb are not suitable nuclei from the viewpoint of radioactivity when irradiated with neutrons. Recently, we have succeeded in replacing the Nb matrix with Ta that has the advantage of shorter half-life of radioactivity. In the present study, an attempt has been made to replace the Ag internal stabilizer with Cu, in the aim of further reducing radioactivity, based on anticipation that Ta would be less reactive with Cu than Nb did.
Sr
MnOKajimoto, Ryoichi; Yoshizawa, Hideki*; Kawasaki, Ryuichi*; Noda, Kohei*; Kuwahara, Hideki*
Journal of the Physical Society of Japan, 74(1), p.502 - 503, 2005/01
Times Cited Count：2 Percentile：19.77(Physics, Multidisciplinary)The spin wave dispersion relation of the C-type antiferromagnetic structure in Nd
Sr
MnO was determined by neutron scattering. The spin exchange interactions show a large anisotropy, which evidences the d
orbital ordering along the axis. The exchange interaction along the direction is fairly large and similar to the value in the ferromagnetic metallic phase, suggesting there is finite hopping of charges along the orbital chains.
YMnOKajimoto, Ryoichi; Yokoo, Tetsuya*; Kofu, Maiko*; Noda, Kohei*; Kuwahara, Hideki*
no journal, ,
no abstracts in English
Sagisaka, Akito; Daido, Hiroyuki; Pirozhkov, A. S.; Ogura, Koichi; Orimo, Satoshi; Mori, Michiaki; Yogo, Akifumi; Nakamura, Shu*; Iwashita, Yoshihisa*; Shirai, Toshiyuki*; et al.
no journal, ,
no abstracts in English
YMnOKajimoto, Ryoichi; Yokoo, Tetsuya*; Kofu, Maiko*; Noda, Kohei*; Kuwahara, Hideki*
no journal, ,
no abstracts in English
-glucosyltransferase from Hiromoto, Takeshi; Honjo, Eijiro*; Tamada, Taro; Kuroki, Ryota; Noda, Hisanobu*; Kazuma, Kohei*; Suzuki, Masahiko*
no journal, ,
UDP-glucose: anthocyanidin 3--glucosyltransferase from (3GT-A) catalyzes the transfer of glucose from UDP-glucose to anthocyanidins such as delphinidin. The glucosylation of delphinidin at the 3-hydroxyl group has been proposed as an initial glucosylation step toward the biosynthesis of ternatins, which are blue anthocyanins found in the petals of . Although the crystal structures of several flavonoid glycosyltransferases (UGTs) were determined, the acceptor-substrate complexes were limited to the flavonol-bound forms. Here, in order to understand the acceptor-recognition scheme of 3GT-A, the crystal structures in complex with anthocyanidin delphinidin and petunidin, and flavonol kaempferol were determined to resolutions of 2.6 , 2.7 , and 1.8 respectively. The enzyme recognition of unstable anthocyanidins was firstly observed in this structural determination; nevertheless, the molecular orientations of these three acceptors in the binding site are different from those of the known flavonoid UGTs, GT1 and UGT78G1. The crystal structures of 3GT-A provide insight not only into anthocyanidin configurations in enzyme, but also into a different binding scheme for acceptor-substrate recognition compared with the known UGTs.
Kaminaga, Kiichi; Shinoda, Kohei; Fukuoka, Sotaro; Nakaue, Hiroki; Yokoya, Akinari
no journal, ,
no abstracts in English
