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111.
Hiroshi Sasaki Atsushi Nakagawa Tomonari Muramatsu Megumi Suganuma Yoriko Sawano Masaki Kojima Keiko Kubota Kenji Takahashi Masaru Tanokura 《Proceedings of the Japan Academy. Series B, Physical and biological sciences》2004,80(9):435
Aspergilloglutamic peptidase from Aspergillus niger is a novel pepstatin-insensitive acid endopeptidase distinct from the well-studied aspartic peptidases, and thus is an interesting target for protein structure/function studies. In the present study, we have determined the three-dimensional structure of the enzyme by X-ray crystallography to a 1.4-Å resolution. The results revealed that the enzyme has a unique structure, composed of two seven-stranded anti-parallel β-sheets which form a β-sandwich structure and appear to have a partial two-fold symmetry, suggesting its possible evolution by gene duplication and that the glutamic acid-110 and glutamine-24 in the heavy chain form a catalytic dyad, consistent with our results obtained by site-directed mutagenesis. 相似文献
112.
Masaru Matsuoka Akihiro Iwamoto Takeshi Ouchi Hiroshi Yoshioka Kazumi Nakatsu 《Journal of heterocyclic chemistry》1993,30(1):173-176
The structure of 1,4-dithiines obtained from orthodihalogeno heterocycles with thiocarbonyl compounds was determined by X-ray structure analysis of the intermolecular charge-transfer complex between 5,7,12,14-tetramethoxydibenzo[b,i]thianthrene and TCNQ. The formation of the thiazole ring has already been reported but the products were confirmed to be 1,4-dithiines by X-ray structure analysis and the previously reported results. 相似文献
113.
Laser-induced photoacoustic spectroscopy was used in a quantitative analysis of Pu in HNO3 medium. Plutonium was quantitatively oxidized to Pu(VI) using Ce(IV). The photoacoustic measurement of Pu(VI) with maximum absorption at 830.5 nm was subsequently performed to determine the concentration. The photoacoustic signal was linearly proportional to the Pu(VI) ion concentration. The detection limit of Pu(VI) was estimated to be 0.5 microg mL(-1) (3sigma) in 3 M HNO3. By the proposed method, Pu concentration was successfully determined in a nuclear waste solution for use in nuclear materials management. 相似文献
114.
Reikichi Iwamoto Masaru Miya Seiichi Mima 《Journal of Polymer Science.Polymer Physics》1979,17(9):1507-1515
Laser Raman spectra of atactic poly(vinyl alcohol) (PVA) after heat treatment and/or swelling in water have been obtained. An amorphous Raman band is observed at 1124 cm?1, while a crystalline Raman band is found at 1147 cm?1. A new method for crystallinity determination is proposed, in which the amorphous band is used instead of the crystalline band. The method is superior to others for water-swollen PVA samples. Laser Raman spectra of swollen PVA revealed that swelling causes destruction of a major fraction of the crystalline regions and the remaining intact crystalline part increases with increasing temperature of heat treatment. 相似文献
115.
Masaru Tsukada 《Zeitschrift für Physik A Hadrons and Nuclei》1974,270(4):351-360
A new theory for the random system with electron correlation is presented, which is an extension of the Hubbard's theory for the random system and also an extension of the CPA for the interacting electron system. The equation of motion for the Green function is solved by the same decoupling method used by Hubbard. The self-consistent relations for the Green function, the self-energy and the effective occupation number are derived. It is predicted in the binary alloy system that tails or satellites of the state density are produced by the combined effect of the randomness and electron correlation. The origin of the tail is the inelastic scattering of the electron byA — B atomic pairs, whose electronic configuration is changed during the scattering. Numerical calculations are reported for a simple model. 相似文献
116.
Masaru Aida 《Journal of Quantitative Spectroscopy & Radiative Transfer》1977,17(3):303-310
The effects of cloud dimensions and orientation on the scattering pattern have been examined assuming rectangular shaped finite clouds corresponding to cumulus. The clouds are illuminated by the visible solar radiation. The analysis shows the following. (1) A cloud of horizontal extent less than 5 times its vertical dimension should be regarded as a finite cloud for estimating scattering patterns. (2) The importance of cloud shape increases with increasing solar zenith angle. (3) Surrounding clouds located at a distance of about 5 times their diameter away from the central cloud do not alter the scattering pattern. The surrounding clouds increase the fraction of reflection as they approach the central cloud, this effect becoming evident when the separation is about twice the cloud diameter, corresponding to a cloud amount of about 25%. 相似文献
117.
Yoshitaka Ishii Koichi Hirao Takehiko Terao Tsutomu Terauchi Makoto Oba Kozaburo Nishiyama Masatsune Kainosho 《Solid state nuclear magnetic resonance》1998,11(3-4):169-175
A solid state NMR method is presented for determination of a backbone dihedral angle φ in peptides, being based on the previously reported method, relayed anisotropy correlation (RACO) NMR [Y. Ishii et al., Chem. Phys. Lett. 256 (1996) 133]. In the present method, the
and the
dipolar tensors in the
system are two-dimensionally (2D) correlated via polarization transfer from
to
under magic angle spinning (MAS). This method was applied to N-acetyl
,
-valine, and the H–C–N–H dihedral angle was determined to be 154.0±1.4° or 206.0±1.4°, the former agreeing with the X-ray value of 154±5°. 相似文献
118.
The surface electronic structure of the binary metal oxide ZrO2/SiO2 was studied by means of XPS and the decrete variational (DV) Xα cluster model calculation. The results show that when ZrO2, was supported on SiO2, the SiO bond of SiO2, neighboring ZrO4, became stronger and that the Brönsted acid site H which is located on the SiO4 unit exhibits stronger acidity. 相似文献
119.
Masaru Matsuo Hiroshi Hattori Shunji Nomura Hiromichi Kawai 《Journal of Polymer Science.Polymer Physics》1976,14(2):223-238
A model relating crystal orientation to the deformation of nylon-6 spherulites under uniaxial stretching is discussed in terms of the orientation distribution functions of reciprocal lattice vectors of crystal planes, such as the (002) and (200) planes. The distribution functions calculated from the model are compared with those obtained from x-ray diffraction experiments. It is found that the crystal a axis and, consequently, the direction of hydrogen bonds within the crystal (α modification) orient parallel to the lamellar axis in the undeformed state, and that the crystal orientation behavior of nylon-6 is much different from that of low-density polyethylene, being characterized by much smaller values of the reorientation parameters of crystallites within orienting lamellae. Moreover, small-angle light scattering for Hv and Vv polarization is also calculated on the basis of the spherulite deformation model by taking the nylon-6 crystal as having orthogonal–biaxial symmetry in optical anisotropy. It is concluded that the Hv scattering can be realized in terms of the proposed model for spherulite deformation by taking into account a considerable contribution of hydrogen bonds to the molecular polarizability, so as to make the polarizability along the crystal a axis larger than that along the b axis. In other words, this conclusion suggests positively birefringent spherulites in the nylon-6 samples studied. 相似文献
120.