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101.
Kazuhiro Usui Yoji Sasahara Ryushi Tazawa Koichi Hagiwara Satoshi Tsukada Toshio Miyawaki Shigeru Tsuchiya Toshihiro Nukiwa 《Respiratory research》2001,2(3):188-5
Background
X-linked agammaglobulinemia (XLA) is a humoral immunodeficiency caused by disruption of the Bruton's tyrosine kinase (BTK) gene. Typical XLA patients suffer recurrent and severe bacterial infections in childhood. 相似文献102.
Nguyen Thi Thu Hoai Ie Sung Shim Katsuichiro Kobayashi Usui Kenji 《Plant Growth Regulation》2003,41(2):159-164
The salt-induced accumulation of some nitrogen compounds (free amino acids, ammonium and urea) in shoots of eight rice cultivars differing in salt tolerance was investigated. Salt treatment (100 mM, 6 days) significantly increased the proline content of shoots but this appeared to be a reaction to stress damage and not associated with salt tolerance, because proline contents were higher in the more sensitive cultivars. Besides proline, some other free amino acids also accumulated leading to a significant increase in the total amino acid content of the stressed seedlings. High levels of free ammonium also accumulated under conditions of stress; this was highly correlated with the accumulation of Na+ in the shoots and negatively correlated with salt tolerance. The accumulation of ammonium was positively correlated with the accumulation of many free amino acids, and also associated with the production of urea in the stressed seedlings. Results from the present investigations suggest that an increase in the concentration of some free amino acids including proline, may be a result of the reassimilation of the stress-induced ammonium. A high capacity to assimilate ammonium may be an important factor in alleviating the consequence of stress because ammonium can be toxic at high concentrations. 相似文献
103.
Our purpose is to develop an efficient synthetic method of obtaining oligosaccharide unit in sufficient amounts to study functions
of glycans. Many exoglycosidases have been used as tools for the oligosaccharide synthesis. In contrast, a limited number
of reports are available on the utilization of endoglycosidases. We describe herewith the efficient synthetic method of useful
oligosaccharides and derivatives as biomaterials utilizing lysozyme, cellulase, and lacto-N-biosidase-mediated transglycosylations. 相似文献
104.
T Murata M Kosugi T Nakamura T Urashima T Usui 《Bioscience, biotechnology, and biochemistry》2001,65(11):2456-2464
We have established a unique enzymatic approach for obtaining sulfated disaccharides using Bacillus circulans beta-D-galactosidase-catalyzed 6-sulfo galactosylation. When 4-methyl umbelliferyl 6-sulfo beta-D-galactopyranoside (S6Gal beta-4MU) was used as a donor, the enzyme induced transfer of 6-sulfo galactosyl residue to GlcNAc acceptor. As a result, the desired compound 6'-sulfo N-acetyllactosamine (S6Gal beta1-4GlcNAc) and its positional isomer 6'-sulfo N-acetylisolactosamine (S6Gal beta1-6GlcNAc) were observed by HPAEC-PAD, in 49% total yield based on the donor added, and in a molar ratio of 1:3.5. With a glucose acceptor, the regioselectivity was substantially changed and S6Gal beta1-2Glc was mainly produced along with beta-(1-1)alpha, beta-(1-3), beta-(1-6) isomers in 74% total yield. When methyl alpha-D-glucopyranoside (Glc alpha-OMe) was an acceptor, the enzyme also formed mainly S6Gal beta1-2Glc alpha-OMe with its beta-(1-6)-linked isomer in 41% total yield based on the donor added. In both cases, it led to the predominant formation of beta-(1-2)-linked disaccharides. In contrast, with the corresponding methyl beta-D-glucopyranoside (Glc beta-OMe) acceptor, S6Gal beta1-3Glc beta-OMe and S6Gal beta1-6Glc beta-OMe were formed in a low total yield of 12%. These results indicate that the regioselectivity and efficiency on the beta-D-galactosidase-mediated transfer reaction significantly depend on the anomeric configuration in the glucosyl acceptors. 相似文献
105.
The Rhodobacter sphaeroides gene encoding subunit IV of the cytochrome b-c1 complex (fbcQ) was cloned and sequenced. The fbcQ cistron is 372 base pairs long and encodes 124 amino acid residues. The molecular mass of subunit IV, deduced from the nucleotide sequence, is 14,384 Da. A hydropathy plot of the predicted amino acid sequence revealed only one transmembrane helix; it is near the C-terminal end. The 3-azido-2-methyl-5-methoxy-6-(3,7-dimethyl[3H]octyl)-1,4-benzoquinone ([3H]azido-Q)-labeled subunit IV was isolated from the [3H]-azido-Q-treated cytochrome b-c1 complex. A ubiquinone-binding peptide was obtained by digesting the labeled subunit IV with V8 protease followed by high performance liquid chromatography separation. Amino acid analysis and partial N-terminal sequencing of this ubiquinone-binding peptide revealed that it corresponded to residues 77-124 of subunit IV. Based on the hydropathy profile and predicted tendency to form alpha-helices and beta-sheets, we propose a structural model for subunit IV. In this model the ubiquinone-binding domain is located near the surface of the membrane. 相似文献
106.
Polyamine hydrochlorides, NaCl and magnesium acetate stimulated the enzymatic dephosphorylation of phosphorylated H2B histone by two forms (large form, mol. wt. 250 000; small form, mol. wt. 30 000) of a pig heart phosphoprotein phosphatase (phosphoprotein phosphohydrolase, EC 3.1.3.16). These ionic compounds stimulated the large form of the enzyme 5--9-fold but stimulated the small form of theenzyme only 2-fold. With phosphorylated H2B histone as substrate, these effectors caused an increase in both Km and V values of the two forms of the enzyme. On the other hand, when a tryptic phosphodecapeptide derived from phosphorylated H2B histone was used as substrate, these effectors were always inhibitory apparently non-competitively with respect to the substrate. Using phosphorylated H1 histone as substrate, these effectors stimulated the large form of the enzyme 2-fold but inhibited the small form. With phosphorylase a as substrate, the reactions were also inhibited by these effectors irrespective of the enzyme employed. With respect to phosphorylase a, this inhibition was apparently of a competitive type for the large form and a non-competitive type for the small form of the enzyme. 相似文献
107.
Katsura Kogure Noriyoshi Sueda Kunio Nakagawa Hideaki Fukawa 《Bioscience, biotechnology, and biochemistry》2013,77(2):435-436
The relationships between dietary levels of the essential amino acids and hepatic polysome profiles of rats were investigated with special attention to the amino acid requirement pattern for the maximum rat growth as determined by other investigators. The basal diet contained a 7% essential amino acid mixture and a 3% non-essential amino acid mixture, with appropriate amounts of other nutrients. Rats were fed test diet for 5 hours and then the polysome profile was determined. The amounts of essential amino acids needed for maximum aggregation of polysome were low for methionine-cystine, leucine and tryptophan as compared with requirements for maximum growth. But in other essential amino acids, the amounts were in almost the same range as those reported for maximum growth by others. The differences between the amino acid requirement patterns for maximum aggregation of hepatic ribosomes and for maximum growth of rats might be due to a difference in amino acid requirements of the liver and whole body. Therefore, the hepatic polysome profile might be used to measure the effect of amino acid supplementation on dietary proteins. The requirement pattern of essential amino acids in other organs may be studied by polysome profile determination. 相似文献
108.
Usui Akira Kitahara Yuichi Matsushita Yutaka Kitajima Miyoko Sakamoto Reiko Watanabe Tsuyoshi Motohashi Nobutaka 《Sleep and biological rhythms》2008,6(1):53-55
Sleep and Biological Rhythms - The patient was a 21-year-old male who complained of daytime sleepiness. His multiple sleep latency test (MSLT) showed multiple sleep onset REM periods (SOREMPs). The... 相似文献
109.
Norikazu Kawai Yukiteru Ouji Masaharu Sakagami Takashi Tojo Noriyoshi Sawabata Masahide Yoshikawa Shigeki Taniguchi 《Biochemistry and Biophysics Reports》2018
Decellularization of tissues is a recently developed technique mostly used to provide a 3-dimensional matrix structure of the original organ, including decellularized lung tissues for lung transplantation. Based on the results of the present study, we propose new utilization of decellularized tissues as inducers of stem cell differentiation. Decellularized lung matrix (L-Mat) samples were prepared from mouse lungs by SDS treatment, then the effects of L-Mat on differentiation of ES cells into lung cells were investigated. ES cell derived-embryoid bodies (EBs) were transplanted into L-Mat samples and cultured for 2 weeks. At the end of the culture, expressions of lung cell-related markers, such as TTF-1 and SP-C (alveolar type II cells), AQP5 (alveolar type I cells), and CC10 (club cells), were detected in EB outgrowths in L-Mat, while those were not found in EB outgrowths attached to the dish. Our results demonstrated that L-Mat has an ability to induce differentiation of ES cells into lung-like cells. 相似文献
110.
In the November 2001 issue of Developmental Cell, Vogel et al. describe that the budding yeast gamma-tubulin, Tub4p, is phosphorylated at a conserved tyrosine in G1 phase of the cell cycle. The results suggest that gamma-tubulin phosphorylation regulates the number and dynamics of microtubules. 相似文献