Differences in water dynamics between the hydrated chitin and hydrated chitosan determined by quasi-elastic neutron scattering

Hirota, Yuki*; Tominaga, Taiki*; Kawabata, Takashi*; Kawakita, Yukinobu; Matsuo, Yasumitsu*

Bioengineering (Internet), 10(5), p.622_1 - 622_17, 2023/05

https://doi.org/10.3390/bioengineering10050622

Data collection for dilute protein solutions via a neutron backscattering spectrometer

Tominaga, Taiki*; Nakagawa, Hiroshi; Sahara, Masae*; Oda, Takashi*; Inoue, Rintaro*; Sugiyama, Masaaki*

Life (Internet), 12(5), p.675_1 - 675_9, 2022/05

https://doi.org/10.3390/life12050675

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 DO was lower than that of a sample cell coated with regular water (HO). 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 DO buffer and the sample container. Consequently, high quality information on protein dynamics could be extracted from dilute protein solutions.

Evaluation of sample cell materials for aqueous solutions used in quasi-elastic neutron scattering measurements

Tominaga, Taiki*; Sahara, Masae*; Kawakita, Yukinobu; Nakagawa, Hiroshi; Yamada, Takeshi*

Journal of Applied Crystallography, 54(6), p.1631 - 1640, 2021/12

https://doi.org/10.1107/S1600576721009687

Conformational dynamics of a multidomain protein by neutron scattering and computational analysis

Nakagawa, Hiroshi; Saio, Tomohide*; Nagao, Michihiro*; Inoue, Rintaro*; Sugiyama, Masaaki*; Ajito, Satoshi; Tominaga, Taiki*; Kawakita, Yukinobu

Biophysical Journal, 120(16), p.3341 - 3354, 2021/08

https://doi.org/10.1016/j.bpj.2021.07.001

A multi-domain protein can have various conformations in solution. Interactions with other molecules result in the stabilization of one of the conformations and change in the domain dynamics. SAXS, a well-established experimental technique, can be employed to elucidate the conformation of a multi-domain protein in solution. NSE spectroscopy is a promising technique for recording the domain dynamics in nanosecond and nanometer scale. Despite the great efforts, there are still under development. Thus, we quantitatively removed the contribution of diffusion dynamics and hydrodynamic interactions from the NSE data via incoherent scattering, revealing the differences in the domain dynamics of the three functional states of a multi-domain protein, MurD. The differences among the three states can be explained by two domain modes.

Position dependency of the scattered intensity in the time-of-flight backscattering spectrometer DNA

Matsuura, Masato*; Yamada, Takeshi*; Tominaga, Taiki*; Kobayashi, Makoto*; Nakagawa, Hiroshi; Kawakita, Yukinobu

JPS Conference Proceedings (Internet), 33, p.011068_1 - 011068_6, 2021/03

https://doi.org/10.7566/JPSCP.33.011068

The position dependence of the scattered intensity in the time-of-flight backscattering spectrometer DNA was investigated. A periodic structure for both vertical (pixel) and horizontal (PSD) directions was observed. The solar slit and over-bending of an analyzer crystal is discussed as a possible origin of the modulation in the intensity. We have developed software program for the systematic correction of the position-dependent intensity and offset energy for the elastic peak. This corrects the deviation from the true scattering intensity and improve the quality of the data, which includes the energy resolution.

Quartz cell for a backscattering spectrometer

Tominaga, Taiki*; Kawakita, Yukinobu; Nakagawa, Hiroshi; Yamada, Takeshi*; Shibata, Kaoru

JPS Conference Proceedings (Internet), 33, p.011086_1 - 011086_5, 2021/03

BB2019-1956.pdf:0.78MB

https://doi.org/10.7566/JPSCP.33.011086

We developed a quartz double cylindrical sample cell optimized for a backscattering neutron spectrometer, especially for BL02 (DNA), MLF in J-PARC. A quartz glass tube, with one end closed, is shaved to obtain a wall thickness of 0.55 mm. The inner tube is properly centered using a protrusion into the outer tube such that the interstice between the outer and inner tubes keeps constant. This quartz cell can be used for samples that should not be in contact with the aluminum surface. We verified cell's background effect between the quartz cell and Al cell by QENS measurements using DO buffer. The elastic intensity profiles of the buffer in a low Q region were identical between both quartz cell and Al cell (A1070). In a high Q region, however, the profiles were different caused by the first sharp diffraction peak of quartz glass. For this region the data should be analyzed by consideration of absorption correction and diffraction in individual thickness of quartz cell.

Gelation process of polyacrylonitrile solutions as studied using small-angle neutron scattering techniques

Nakano, Shota*; Konno, Soken*; Tomita, Naoto*; Matsuba, Go*; Tominaga, Taiki*; Takata, Shinichi

Microsystem Technologies, 22(1), p.57 - 63, 2016/01

https://doi.org/10.1007/s00542-015-2653-x

We studied the structural formation process of polyacrylonitrile (PAN) gelation in a wide-spatial scale with the small and wide angle neutron scattering in MLF, J-PARC. In micron-scale structure, light transmittance and gelation time were evaluated. The presence of water in the mixed solvent accelerated the phase separation and gelation. In the opaque-gel case, we observed the nanometer-scaled correlation of crystalline cross-linking points and smooth boundary of two micron-scaled phases due to liquid-liquid phase separation. The correlation length is independent of the annealing time, then the cross-linking point exists locally and micro-gelation occurs during phase separation. By contrast, in the transparent-gel case, the correlation length was found to increase throughout the gelation process, and the entanglements of the polymer chains play a role similar to that of cross-linking points.

Neutron studies on soft matter by TAIKAN; Tough hydrogels "Double network gels"

Tominaga, Taiki; Suzuki, Junichi*; Takata, Shinichi; Shinohara, Takenao; Oku, Takayuki; Nakatani, Takeshi; Inamura, Yasuhiro; Suzuya, Kentaro; Aizawa, Kazuya; Arai, Masatoshi; et al.

no journal, , 

no abstracts in English

Software development of the smaller-angle neutron scattering instrument TAIKAN of J-PARC

Takata, Shinichi; Suzuki, Junichi*; Shinohara, Takenao; Nakatani, Takeshi; Inamura, Yasuhiro; Ito, Takayoshi*; Oku, Takayuki; Oishi, Kazuki*; Iwase, Hiroki*; Tominaga, Taiki; et al.

no journal, , 

The time-of-flight smaller-angle neutron scattering instrument, named as TAIKAN, has been constructed at the beam line of BL15 in the Materials and Life Science Experimental Facility (MLF) of J-PARC. TAIKAN is designed for efficient measurements in wide-q range of 5 10 to 10[]. The detector system is composed of small-, medium-, and high-angle detector banks and a backward detector bank with arrays of one dimensional He position sensitive detectors, besides the high-resolution detector with spatial resolution of about 0.5 mm will be installed near the center of small angle bank. In the data analysis software of TAIKAN, therefore, it is necessary to be able to execute the data reduction and some corrections to the enormous amounts of data including time information. And then, it is required that the all data processed can be comprehensibly displayed in one screen image. We will present about the data analysis software for TAIKAN now being developed.

Time-shearing measurements of soft matter using J-PARC/TAIKAN (BL15)

Tominaga, Taiki; Takata, Shinichi; Suzuki, Junichi*; Shinohara, Takenao; Oku, Takayuki; Nakatani, Takeshi; Inamura, Yasuhiro; Suzuya, Kentaro; Aizawa, Kazuya; Arai, Masatoshi; et al.

no journal, , 

no abstracts in English