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1.
Byung-In Lee Devkumar Mustafi Wonhwa Cho Yasushi Nakagawa 《Journal of biological inorganic chemistry》2003,8(3):341-347
The pancreas secretes primarily two types of metabolically important proteins: digestive enzymes and hormones. Lithostathine (LIT) is the only protein excreted from the pancreas that has no known digestive or hormonal activity. Human lithostathine is a 144-amino acid glycoprotein synthesized by the exocrine pancreas that has been implicated in various physiological functions, including inhibition of pancreatic stone formation. To better understand the physiological function of LIT, we expressed the recombinant LIT protein in Escherichia coli and measured its calcium binding properties by equilibrium dialysis and electron paramagnetic resonance (EPR) spectroscopy. Equilibrium dialysis with (45)Ca(2+) showed that LIT binds Ca(2+) with 1:1 stoichiometry. EPR studies using the divalent vanadyl (VO(2+)) ion as a paramagnetic substitute for Ca(2+) also showed that VO(2+) binds to LIT with a metal:protein binding stoichiometry of 1:1 and that VO(2+) competes with Ca(2+) in binding to LIT. Mutations of a cluster of acidic residues on the molecular surface (E30A, D31A, E33A, D37A, D72A, and D73A) resulted in almost complete loss (95-100%) of binding of Ca(2+) and VO(2+), showing that these residues are critical for calcium binding by LIT. 相似文献
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Tetsuya Kawai Iwase Kazuhiko Noriko Takaya Yuko Yamaguchi Ryuta Kishii Yasushi Kohno Haruaki Kurasaki 《Bioorganic & medicinal chemistry letters》2017,27(4):1045-1049
We attempted to optimize sulfonamide-based non-alkyne LpxC inhibitors by focusing on improvements in enzyme inhibitory and antibacterial activity. It was discovered that inhibitors possessing 2-aryl benzofuran as a hydrophobe exhibited good activity. In particular, compound 21 displayed impressive antibacterial activity (E. coli MIC = 0.063 μg/mL, K. pneumoniae MIC = 0.5 μg/mL, and P. aeruginosa MIC = 0.5 μg/mL), and is a promising lead for further exploration as an antibacterial agent. 相似文献
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Yasutaka Fushimi Tomohisa Okada Yasushi Takagi Takeshi Funaki Jun C. Takahashi Susumu Miyamoto Kaori Togashi 《PloS one》2016,11(2)
Moyamoya disease (MMD) is a chronic, progressive, cerebrovascular occlusive disease that causes abnormal enlargement of collateral pathways (moyamoya vessels) in the region of the basal ganglia and thalamus. Cerebral revascularization procedures remain the preferred treatment for patients with MMD, improving the compromised cerebral blood flow (CBF). However, voxel based analysis (VBA) of revascularization surgery for MMD based on data from pre- and postoperative data has not been established. The latest algorithm called as Diffeomorphic Anatomical Registration Through Exponentiated Lie Algebra (DARTEL) has been introduced for VBA as the function of statistical parametric mapping (SPM8), and improved registration has been achieved by SPM8 with DARTEL. In this study, VBA was conducted to evaluate pre- and postoperative single photon emission computed tomography (SPECT) images for MMD by SPM8 with DARTEL algorithm, and the results were compared with those from SPM8 without DARTEL (a conventional method). Thirty-two patients with MMD who underwent superficial temporal artery-middle cerebral artery (STA-MCA) bypass surgery as the first surgery were included and all patients underwent pre- and postoperative 3D T1-weighted imaging and SPECT. Pre- and postoperative SPECT images were registered to 3D T1-weighted images, then VBA was conducted. Postoperative SPECT showed more statistically increased CBF areas in the bypassed side cerebral hemisphere by using SPM8 with DARTEL (58,989 voxels; P<0.001), and increased ratio of CBF after operation was less than 15%. Meanwhile, postoperative SPECT showed less CBF increased areas by SPM8 without DARTEL. In conclusion, VBA was conducted for patients with MMD, and SPM8 with DARTEL revealed that postoperative SPECT showed statistically significant CBF increases over a relatively large area and with at most 15% increase ratio. 相似文献
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Kenji Hirose Rieko Ishima Kazuyuki Akasaka Yasushi Kawata 《Journal of Protein Chemistry》1992,11(4):407-408
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The egg white was treated under various whipping conditions, and its foaminess measured. At the same time, the amounts of the coagulated proteins formed from each egg white and their constituent hexose were measured. From these results, discussions were made about the relation between the foaminess of the egg white and the amount of the coagulated proteins under various whipping conditions. 相似文献
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Intracellular protease (IPLB) of Streptococcus cremoris was extracted from the cells, which were cultivated in liquid media, by momentarily disrupting between two disks by high pressure.The hydrolyzing modes of αs-, crude k-, β-, and whole casein by IPLB of Str. cremoris or rennet were observed through the released amounts of tyrosine, sialic acid, NPN, and calcium insensitive substance. Relative specific turbidity of casein solution and dissymmetry coefficient of casein were measured. Particle weight and UV absorption spectrum of each high molecular hydrolyzate of whole casein were also determined.Among four kinds of casein fractions, αs- or crude k-casein was most easily hydrolyzed by IPLB of Str. cremoris or rennet. Relative specific turbidity of crude k-casein solution was remarkably, but those of αs-, β-, and whole casein slightly increased by the action of IPLB of Str. cremoris or of rennet. Changes of dissymmetry coefficients were negligibly induced by these two enzymes. Absorption spectrum of IPLB-Str. cremoris-casein showed some conformational change.It was recognized that intracellular protease (IPLB) of L. bulgaricus, L. helveticus or Str. lactis, all together, more easily hydrolyzed αs-casein than crude k-, β-, and whole casein. By the actions of three IPLBs, relative specific turbidity of crude k-casein solution remarkably but those of αs-, β-, and whole casein slightly increased, and dissymmetry coefficients of these casein fractions changed negligibly.Particle weight of whole casein hydrolyzed by each IPLB for five days was larger than that of control casein. UV absorption of each whole casein hydrolyzed by a IPLB increased at the wave length range of 280~250 mμ. 相似文献
10.
We investigated the effects of near-infrared irradiation on the photoconversion of Chenopodium album water-soluble chlorophyll-binding protein (CaWSCP) in the presence of sodium hydrosulfite and found a further photoconversion from CP742 to CP763, a novel form of CaWSCP. Interestingly, one-third of the absorption peak at 668 nm was recovered in CP763, but re-irradiation under oxidative conditions eliminated the photo convertibility of CaWSCP. 相似文献