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91.
Akira Kuninaka Masao Kumagai Kazuo Fujiyama Masaru Ogura Shinji Sakata Seishiro Yonei 《Bioscience, biotechnology, and biochemistry》2013,77(6):1437-1439
Substance B, the major component, isolated from rice plant treated with probenzaole and inoculated, having anti-conidial germination activity against blast fungus, was found to be a mixture of fatty acids, including palmitic acid, linoleic acid and linolenic acid. The main compound of substance B was linolenic acid, having strong anti-conidial germination activity. It was determined as α-linolenic acid by gas chromatographic analysis. The minor components showed little or no anti-conidial germination activity. 相似文献
92.
Tateki Hayashi Akihiko Terao Shinji Ueda Mitsuo Namiki 《Bioscience, biotechnology, and biochemistry》2013,77(11):3139-3144
Ascorbic acid-protein mixtures of low moisture content stored for 2~3 days in aerobic conditions at 60°C produced a red coloration, which was shown to have resulted from an amino-carbonyl reaction of oxidized ascorbic acid (dehydroascorbic acid, DHA) by the facts that DHA-casein or ovalbumin systems yielded a rapid red coloration in low moisture conditions as well as in an ethanol suspension. Zein showed only a weak red coloration with DHA. An apparent decrease in the free amino group, as determined by the TNBS method, was observed to be associated in parallel with the red pigment formation. The electrophoretic pattern of ovalbumin changed significantly upon incubation with DHA, together with the formation of the red pigment. The red pigment extracted from a DHA-casein system showed an absorption spectrum, TLC Rf value, and hydrolyzed products (DHA and scorbamic acid) identical to those of 2,2′-nitrilo di-2(2)-deoxy-l-ascorbic acid mono ammonium salt, produced from DHA and amino acid. Formation of the red pigment was also observed in the reaction of DHA with Nα-acetyl lysine. These results indicate that the ε-amino group of lysine in protein can be attributed to the formation of a red pigment identical with NDA. 相似文献
93.
Shinji Nagata Nobuyoshi Esaki Katsuyuki Tanizawa Hidehiko Tanaka Kenji Soda 《Bioscience, biotechnology, and biochemistry》2013,77(4):1137-1141
Two genes of Pseudomonas putida (IFO 12996) which code for enzymes participating in amino acid metabolism, were cloned in Escherichia coli C600 using pBR322 as a vector. pST7549 is a 7.9 kb hybrid plasmid DNA which is composed of four SalI fragments (0.3, 1.4, 1.9 and 4.3 kb), and codes for β-isopropylmalate dehydrogenase (EC 1.1.1.85) in l-leucine biosynthesis. The enzyme activity in the crude extract from E. coli C600 bearing pST7549 was 80 ~ 90% lower than that of E. coli K12 or P. putida. When the foreign SalI fragments derived from P. putida were subcloned, a 1.9 kb SalI fragment was found to encode β-isopropylmalate dehydrogenase and it did not contain the promoter of P. putida DNA. Plasmid pST6961 has a 1.8 kb insert derived from the P. putida DNA in the SalI site of pBR322. E. coli cells carrying this recombinant plasmid show no leucine racemase activity and no d-leucine transaminase activity, but five-times higher d-leucine oxidation activity than the host strain, E. coli. Enzymological studies have suggested that plasmid pST6961 codes for d-amino acid dehydrogenase, a key enzyme in d-amino acid metabolism. 相似文献
94.
95.
Hidehiko Kumagai Nobukazu Kashima Hiroshi Torii Hideaki Yamada Hitoshi Enei Shinji Okumuea 《Bioscience, biotechnology, and biochemistry》2013,77(3):472-482
Crystalline tyrosine phenol lyase was prepared from the cell extract of Erwinia herbicola grown in a medium supplemented with l-tyrosine. The crystalline enzyme was homogeneous by the criteria of ultracentrifugation and acrylamide gel electrophoresis. The molecular weight was determined to be approximately 259,000. The crystalline enzyme catalyzed the conversion of l-tyrosine into phenol, pyruvate and ammonia, in the presence of added pyridoxal phosphate. The enzyme also catalyzed pyruvate formation from d-tyrosine, S-methyl-l-cysteine, 3, 4-dihydroxyphenyl-l-alanine, l- and d-serine, and l- and d-cysteine, but at lower rates than from l-tyrosine. l-Phenyl-alanine, l-alanine, phenol and pyrocatechol inhibited pyruvate formation from l-tyrosine.Crystalline tyrosine phenol lyase from Erwinia herbicola is inactive in the absence of added pyridoxal phosphate. Binding of pyridoxal phosphate to the apoenzyme is accompanied by pronounced increase in absorbance at 340 and 425 mμ. The amount of pyridoxal phosphate bound to the apoenzyme was determined by equilibrium dialysis to be 2 moles per mole of enzyme. Addition of the substrate, l-tyrosine, or the competitive inhibitors, l-alanine and l-phenyl-alanine, to the holoenzyme causes appearance of a new absorption peak near 500 mμ which disappears as the substrate is decomposed but remains unchanged in the presence of the inhibitor. 相似文献
96.
Jiro Sekiya Shinji Numa Tadahiko Kajiwara Akikazu Hatanaka 《Bioscience, biotechnology, and biochemistry》2013,77(1):185-190
The synthetic activity for 3Z-hexenal, an important precursor of 3Z-hexenol (leaf alcohol), was localized in chloroplasts of Thea sinensis leaves. 3Z-Hexenal, which is easily isomerized to 2E-hexenal (leaf aldehyde), was formed from linolenic acid in the presence of oxygen. 13-l-Hydroperoxy-linolenic acid also served as a precursor, but the triglyceride and methyl ester of linolenic acid did not. This enzyme system appeared to be tightly bound to the lamellae membranes of chloroplasts. 相似文献
97.
Natural killer (NK) cell malignancies, particularly aggressive NK cell leukaemias and lymphomas, have poor prognoses. Although recent regimens with L-asparaginase substantially improved outcomes, novel therapeutic approaches are still needed to enhance clinical response. Resveratrol, a naturally occurring polyphenol, has been extensively studied for its anti-inflammatory, cardioprotective and anti-cancer activities. In this study, we investigated the potential anti-tumour activities of resveratrol against the NK cell lines KHYG-1, NKL, NK-92 and NK-YS. Resveratrol induced robust G0/G1 cell cycle arrest, significantly suppressed cell proliferation and induced apoptosis in a dose- and time-dependent manner for all four cell lines. In addition, resveratrol suppressed constitutively active STAT3 in all the cell lines and inhibited JAK2 phosphorylation but had no effect on other upstream mediators of STAT3 activation, such as PTEN, TYK2, and JAK1. Resveratrol also induced downregulation of the anti-apoptotic proteins MCL1 and survivin, two downstream effectors of the STAT3 pathway. Finally, resveratrol induced synergistic effect on the apoptotic and antiproliferative activities of L-asparaginase against KHYG-1, NKL and NK-92 cells. These results suggest that resveratrol may have therapeutic potential against NK cell malignancies. Furthermore, our finding that resveratrol is a bonafide JAK2 inhibitor extends its potential benefits to other diseases with dysregulated JAK2 signaling. 相似文献
98.
99.
Shinji Sato Akihiro Murakami Akiko Kuwajima Kazuhiko Takehara Tsuneyo Mimori Atsushi Kawakami Michiaki Mishima Takafumi Suda Mariko Seishima Manabu Fujimoto Masataka Kuwana 《PloS one》2016,11(4)
ObjectiveAutoantibodies to melanoma differentiation-associated gene 5 (MDA5) are specifically expressed in patients with dermatomyositis (DM) and are associated with a subset of DM patients with rapidly progressive interstitial lung disease (RP-ILD). Here, we examined the clinical utility of a newly developed enzyme-linked immunosorbent assay (ELISA) system for detecting these antibodies.MethodsHere we developed an improved ELISA for detecting anti-MDA5 antibodies. We then performed a multicenter clinical study involving 8 medical centers and enrolled 242 adult patients with polymyositis (PM)/DM, 190 with non-PM/DM connective tissue disease (CTD), 154 with idiopathic interstitial pneumonia (IIP), and 123 healthy controls. Anti-MDA5 antibodies in the patients’ serum samples were quantified using our newly developed ELISA, and the results were compared to those obtained using the gold-standard immunoprecipitation (IP) assay. In addition, correlations between the ELISA-quantified anti-MDA5 antibodies and clinical characteristics were evaluated.ResultsIn patients with PM/DM, the anti-MDA5 antibody measurements obtained from the ELISA and IP assay were highly concordant; the ELISA exhibited an analytical sensitivity of 98.2%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 99.5% (compared to the IP assay). Anti-MDA5 antibodies were detected in 22.7% of the DM patients, but not in any of the patients with PM, non-PM/DM CTD, or IIP. Clinically amyopathic DM, RP-ILD, arthritis, and fever were more prevalent in DM patients who were anti-MDA5 antibody-positive than in those who were antibody-negative (P ≤ 0.0002 for all comparisons). In addition, anti-MDA5 antibody-positive patients with RP-ILD exhibited higher antibody levels than those without RP-ILD (P = 0.006).ConclusionOur newly developed ELISA can detect anti-MDA5 antibodies as efficiently as the gold standard IP assay and has the potential to facilitate the routine clinical measurement of anti-MDA5 antibodies in patients who suspected to have DM. 相似文献
100.