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71.
Adachi O Ano Y Akakabe Y Shinagawa E Matsushita K 《Applied microbiology and biotechnology》2008,81(1):143-151
Chlorogenate hydrolase (EC 3.1.1.42, CHase) was highly induced in mycelia of Aspergillus sojae AKU 3312 grown in Czapek medium containing either instant coffee powder or coffee pulp as inducer. No CHase formation was
observed in the mycelia when cultivated without the inducer. CHase was purified readily from CHase-induced mycelia to high
homogeneity, and the purified CHase revealed the molecular weight of 180,000 consisting of two identical subunits of 88 kDa.
Equimolar quinate (QA) and caffeate (CA) were confirmed on hydrolysis of chlorogenate (CGA). The purified CHase was only useful
for a laboratory scale hydrolysis of CGA. For practical QA and CA production using scaled up hydrolysis of vegetable extracts
of natural CGA resources, the enzyme activity of purified CHase decreased and denatured irreversibly. Preparation of coffee
pulp koji and its application to QA and CA production were proposed instead of purified CHase. When coffee pulp koji was heated at
60°C for 30 min, CHase survived without any appreciable loss of enzyme activity while vegetative mycelial growth and spore
germination were terminated. The heated coffee pulp koji thus prepared was effective itself as stable immobilized catalyst
of CHase for QA and CA production from vegetable CGA resources such as coffee powders, coffee pulp, and others. 相似文献
72.
Urano E Kariya Y Futahashi Y Ichikawa R Hamatake M Fukazawa H Morikawa Y Yoshida T Koyanagi Y Yamamoto N Komano J 《FEBS letters》2008,582(29):4053-4058
We conducted a phenotypic cDNA screening using a T cell line-based assay to identify human genes that render cells resistant to human immunodeficiency virus type 1 (HIV-1). We isolated potential HIV-1 resistance genes, including the carboxy terminal domain (CTD) of bromodomain-containing protein 4 (Brd4). Expression of GFP-Brd4-CTD was tolerated in MT-4 and Jurkat cells in which HIV-1 replication was markedly inhibited. We provide direct experimental data demonstrating that Brd4-CTD serves as a specific inhibitor of HIV-1 replication in T cells. Our method is a powerful tool for the identification of host factors that regulate HIV-1 replication in T cells. 相似文献
73.
74.
Nakajima Y Imanishi M Itou S Hamashima H Tomishima Y Washizuka K Sakurai M Matsui S Imamura E Ueshima K Yamamoto T Yamamoto N Ishikawa H Nakano K Unami N Hamada K Hattori K 《Bioorganic & medicinal chemistry letters》2008,18(18):5037-5040
Identification and SAR study of novel series of beta(3)-AR agonists with benzoic acid are described. Conversion of ether linkage position of phenoxybenzoic acid derivative 2b led to compound 7b with moderate beta(3)-AR activity. Further modification in right, center and left parts of compound 7b was investigated to improve the beta(3)-AR potency and selectivity. Compounds 7g and 7k, with the bulky aliphatic-substituted group at 2-position of benzoic acid moiety, were identified as potent and selective beta(3)-AR agonists. In addition, in vivo efficacy of compounds 7g and 7k was exhibited on dog OAB model. 相似文献
75.
We describe a procedure for DNA methylation analysis using the bisulfite-mediated cytosine-to-uracil conversion of a target DNA followed by methylation-specific polymerase chain reaction (MSP) and phosphate affinity polyacrylamide gel electrophoresis (PAGE). The MSP was performed using a 1:1 mixture of 5′-phosphorylated methylation-specific and 5′-OH non-methylation-specific primers. The PAGE using an immobilized phosphate-binding tag molecule (i.e., a polyacrylamide-bound dizinc(II) complex, Zn2+-Phos-tag), which selectively captures the 5′-phosphorylated DNA fragment, enabled the mobility shift detection of the methylation-specific product as a slower migration band. Using this novel procedure, we demonstrated the detection of a methylated cytosine base in a pUC19 plasmid. 相似文献
76.
77.
A novel fluorometric oligonucleotide
assay to measure O 6-methylguanine DNA
methyltransferase, methylpurine DNA glycosylase, 8-oxoguanine DNA glycosylase
and abasic endonuclease activities: DNA repair status in human breast
carcinoma cells overexpressing methylpurine DNA glycosylase 总被引:3,自引:0,他引:3
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Emiko L. Kreklau Melissa Limp-Foster Naili Liu Yi Xu Mark
R. Kelley Leonard C. Erickson 《Nucleic acids research》2001,29(12):2558-2566
DNA repair status plays a major role in mutagenesis, carcinogenesis and resistance to genotoxic agents. Because DNA repair processes involve multiple enzymatic steps, understanding cellular DNA repair status has required several assay procedures. We have developed a novel in vitro assay that allows quantitative measurement of alkylation repair via O6-methylguanine DNA methyltransferase (MGMT) and base excision repair (BER) involving methylpurine DNA glycosylase (MPG), human 8-oxoguanine DNA glycosylase (hOGG1) and yeast and human abasic endonuclease (APN1 and APE/ref-1, respectively) from a single cell extract. This approach involves preparation of cell extracts in a common buffer in which all of the DNA repair proteins are active and the use of fluorometrically labeled oligonucleotide substrates containing DNA lesions specific to each repair protein. This method enables methylation and BER capacities to be determined rapidly from a small amount of starting sample. In addition, the stability of the fluorometric oligonucleotides precludes the substrate variability caused by continual radiolabeling. In this report this technique was applied to human breast carcinoma MDA-MB231 cells overexpressing human MPG in order to assess whether up-regulation of the initial step in BER alters the activity of selected other BER (hOGG1 and APE/ref-1) or direct reversal (MGMT) repair activities. 相似文献
78.
The unicellular green algae Chlorella ellipsoidea was used tostudy transient changes in the energy state of adenylates andthe redox states of pyridine nucleotides induced by environmentalchanges. The transition from anaerobic to aerobic conditionsin the dark induced a sharp rise in the ATP ratio [ATP/(ATP+ADP+AMP)],a sudden decrease in the NADH ratio [NADH/(NAD++NADPH)] anda transient drop in the NADPH ratio [NADPH/(NADP++NADPH)]. Illuminationafter a dark period under anaerobic, CO2-free conditions inducedsharp increases in the ATP and NADPH ratios and a slower decreasein the NADH ratio. Illumination under aerobic conditions, ineither the presence or absence of CO2, caused a sharp increasein the NADPH ratio, a small increase in the ATP ratio and aslower increase in the NADH ratio. In the presence of CO2, asubsequent large drop in the NADPH ratio occurred. Darkeningunder anaerobic, CO2-free conditions induced a sudden decreasein the ATP ratio, a temporary fall in the NADPH ratio and aslow increase in the NADH ratio. Darkening under aerobic conditionsinduced transient drops in the ATP and NADPH ratios and a suddendrop in the NADH ratio. The addition of CO2 to the atmospherewith illumination produced a decrease in all three parameters. These results are discussed in relation to current theoriesof the interaction between photosynthesis and respiration. Ourobservations indicate that the energy and reducing potentialsgenerated by photochemical processes are used for and controlother processes besides CO2 fixation in photosynthetic cells. (Received December 3, 1981; Accepted May 4, 1982) 相似文献
79.
80.
Min-Kyoo Shin Edwin Vázquez-Rosa Yeojung Koh Matasha Dhar Kalyani Chaubey Coral J. Cintrón-Pérez Sarah Barker Emiko Miller Kathryn Franke Maria F. Noterman Divya Seth Rachael S. Allen Cara T. Motz Sriganesh Ramachandra Rao Lara A. Skelton Machelle T. Pardue Steven J. Fliesler Chao Wang Andrew A. Pieper 《Cell》2021,184(10):2715-2732.e23
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