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51.
Noda M Kawahara Y Ichikawa A Matoba Y Matsuo H Lee DG Kumagai T Sugiyama M 《The Journal of biological chemistry》2004,279(44):46143-46152
An antibiotic, D-cycloserine (DCS), inhibits the catalytic activities of alanine racemase (ALR) and d-alanyl-d-alanine ligase (DDL), which are necessary for the biosynthesis of the bacterial cell wall. In this study, we cloned both genes encoding ALR and DDL, designated alrS and ddlS, respectively, from DCS-producing Streptomyces lavendulae ATCC25233. Each gene product was purified to homogeneity and characterized. Escherichia coli, transformed with a pET vector carrying alrS or ddlS, displays higher resistance to DCS than the same host carrying the E. coli ALR- or DDL-encoded gene inserted into the pET vector. Although the S. lavendulae DDL was competitively inhibited by DCS, the K(i) value (920 microM) was obviously higher (40 approximately 100-fold) than those for E. coli DdlA (9 microM) or DdlB (27 microM). The high K(i) value of the S. lavendulae DDL suggests that the enzyme may be a self-resistance determinant in the DCS-producing microorganism. Kinetic studies for the S. lavendulae ALR suggest that the time-dependent inactivation rate of the enzyme by DCS is absolutely slower than that of the E. coli ALR. We conclude that ALR from DCS-producing S. lavendulae is also one of the self-resistance determinants. 相似文献
52.
Identification of expressed genes linked to malignancy of human colorectal carcinoma by parametric clustering of quantitative expression data 总被引:3,自引:0,他引:3
53.
Adapter-tagged competitive PCR (ATAC-PCR) is an advanced version of competitive quantitative PCR that is characterized by the addition of unique adapters to cDNA derived from each sample RNA. Using multiple adapters, we can accurately measure the relative expression ratios of many samples, with a calibration curve obtained from internal standards included in the same reaction. ATAC-PCR can identify differences in gene expression as small as twofold, even from very small amounts of sample RNA. This technique is suitable for confirming results obtained with cDNA microarrays or differential display, and it can process more than a thousand of genes per day when used in conjunction with a capillary DNA sequencer. 相似文献
54.
Sharov AA Piao Y Matoba R Dudekula DB Qian Y VanBuren V Falco G Martin PR Stagg CA Bassey UC Wang Y Carter MG Hamatani T Aiba K Akutsu H Sharova L Tanaka TS Kimber WL Yoshikawa T Jaradat SA Pantano S Nagaraja R Boheler KR Taub D Hodes RJ Longo DL Schlessinger D Keller J Klotz E Kelsoe G Umezawa A Vescovi AL Rossant J Kunath T Hogan BL Curci A D'Urso M Kelso J Hide W Ko MS 《PLoS biology》2003,1(3):E74
55.
Vegetables are rich source of antioxidative components such as ascorbic acid and polyphenols, which scavenge free radicals and reactive oxygen species and prevent life-style related diseases. In this work, the changes of radical-scavenging activity in shredded red and green cabbage leaves during storage were determined as well as ascorbic acid and polyphenol contents. Shredded cabbage leaves were stored at 10 degrees C for 7 days in the presence or absence of oxygen. Radical-scavenging activity, ascorbic acid content, and polyphenol content of shredded cabbage leaves remained for 7 days in the presence and absence of oxygen. These results demonstrate that the radical-scavenging activity, ascorbic acid, and polyphenols are stable in shredded cabbage leaves and that oxygen does not affect the activity and active components. 相似文献
56.
Phospholipase A2 (PLA2) as a calcium-binding form, produced by Streptomyces violaceoruber, was crystallized in a form suitable for the diffraction analysis using the vapor diffusion method. Crystals were grown in 0.1 M Tris-HCl buffer (pH 8.5), 20 mM Ca2+ containing 50-60% (v/v) 2-methyl-2,4-pentanediol as a precipitant. They belong to the monoclinic space group P2(1), with the cell dimensions a=38.3 A, b=54.3 A, c=30.6 A, and beta=90.2 degrees. The crystals diffract the X-ray well and the diffraction intensity data were collected up to 1.6 A resolution. The crystal volume per unit mass, V(M) is 2.35 A3 Da(-1) with one molecule in the asymmetric unit, which corresponds to a solvent content of 47.7%. 相似文献
57.
Yamada Y Matoba N Usui H Onishi K Yoshikawa M 《Bioscience, biotechnology, and biochemistry》2002,66(6):1213-1217
Ovokinin(2-7) (RADHPF), an orally active antihypertensive peptide derived from ovalbumin, lowers blood pressure in SHRs at a dose of 10 mg/kg. Attempts were made to potentiate its anti-hypertensive activity by replacing the amino acid residues in [Pro2, Phe3]-ovokinin(2-7), which was previously reported to have 33-fold stronger activity than ovokinin(2-7). The anti-hypertensive activity of [Pro2, Phe3]-ovokinin(2-7) was improved by replacement of the C-terminal Phe residue with Trp. Then, the best amino acid residues at other positions for the anti-hypertensive effect were selected. RPLKPW, the most potent derivative obtained, showed significant anti-hypertensive activities at a dose of 0.1 mg/kg after oral administration in spontaneously hypertensive rats (SHRs). Thus, RPLKPW showed 100-fold more potent anti-hypertensive activity than ovokinin(2-7). 相似文献
58.
Construction of preferential cDNA microarray specialized for human colorectal carcinoma: molecular sketch of colorectal cancer 总被引:11,自引:0,他引:11
Takemasa I Higuchi H Yamamoto H Sekimoto M Tomita N Nakamori S Matoba R Monden M Matsubara K 《Biochemical and biophysical research communications》2001,285(5):1244-1249
cDNA microarray analyses can be used to identify candidate genes that play important roles in human carcinogenesis. To gain insight into the molecular sketch of colorectal cancer, we have constructed cDNA microarrays specialized for colorectal cancer, which we named "Colonochip" by selecting genes that are expressed in colorectal cancer, normal colonic mucosa, and liver metastatic cancer tissues. This microarray contained 4608 nonredundant cDNA clones from over 30,000 cDNA clones derived from the three types of human cDNA libraries, as well as clones from 170 additional conventional major genes suspected to be involved in colorectal carcinogenesis, according to literatures. Using this "Colonochip," we were able to identify 59 genes showing twofold or more differential expression between primary cancer and normal colonic mucosa, potent candidates for diagnosis, and therapy of colorectal cancer for further studies. 相似文献
59.
Design and production of genetically modified soybean protein with anti-hypertensive activity by incorporating potent analogue of ovokinin(2-7) 总被引:4,自引:0,他引:4
The potent anti-hypertensive peptide, RPLKPW, has been designed based on the structure of ovokinin(2-7). The sequence encoding this peptide was introduced into three homologous sites in the gene for soybean beta-conglycinin alpha' subunit. The native alpha' subunit as well as the modified, RPLKPW-containing alpha' subunit were expressed in Escherichia coli, recovered from the soluble fraction and then purified by ion-exchange chromatography. The RPLKPW peptide was released from recombinant RPLKPW-containing alpha' subunit after in vitro digestion by trypsin and chymotrypsin. Moreover, the undigested RPLKPW-containing alpha' subunit given orally at a dose of 10 mg/kg exerted an anti-hypertensive effect in spontaneously hypertensive rats, unlike the native alpha' subunit. These results provide evidence for the first time that a physiologically active peptide introduced into a food protein by site-directed mutagenesis could practically function in vivo even at a low dose. 相似文献
60.
Arata Honda Masanori Hatori Michiko Hirose Chizumi Honda Haruna Izu Kimiko Inoue Ryutaro Hirasawa Shogo Matoba Sumie Togayachi Hiroyuki Miyoshi Atsuo Ogura 《The Journal of biological chemistry》2013,288(36):26157-26166
Although induced pluripotent stem (iPS) cells are indistinguishable from ES cells in their expression of pluripotent markers, their differentiation into targeted cells is often limited. Here, we examined whether the limited capacity of iPS cells to differentiate into neural lineage cells could be mitigated by improving their base-line level of pluripotency, i.e. by converting them into the so-called “naive” state. In this study, we used rabbit iPS and ES cells because of the easy availability of both cell types and their typical primed state characters. Repeated passages of the iPS cells permitted their differentiation into early neural cell types (neural stem cells, neurons, and glial astrocytes) with efficiencies similar to ES cells. However, unlike ES cells, their ability to differentiate later into neural cells (oligodendrocytes) was severely compromised. In contrast, after these iPS cells had been converted to a naive-like state, they readily differentiated into mature oligodendrocytes developing characteristic ramified branches, which could not be attained even with ES cells. These results suggest that the naive-like conversion of iPS cells might endow them with a higher differentiation capacity. 相似文献