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991.
Shigeru Matsuzaki Koei Hamana Masaru Niitsu Keijiro Samejima Satoshi Yamashita 《FEMS microbiology letters》1987,48(1-2):1-4
Abstract When the yeasts Saccharomyces cerevisiae, Candida albicans and Schizosaccharomyces pombe and the thermophilic bacteria Bacillus stearothermophilus and Bacillus acidocaldarius were cultured in the presence of homospermidine, a new compound accumulated in the cells within a few days. This compound was identified as aminopropylhomospermidine [NH2 (CH2 )3 NH (CH2 )4 NH(CH2 )4 NH2 ] by gas chromatographymass spectrometry (GC-MS) and by the enzymatic cleavage method developed in our laboratories. This polyamine was not produced from homospermidine in Escherichia coli, Bacillus subtilis, Bacillus alkalophilus , or a eukaryotic protozoon, Tetrahymena pyriformis , none of which usually contains appreciable amounts of spermine. These findings suggest that the synthesis of aminopropylhomospermidine from homospermidine is mediated by spermine synthase. 相似文献
992.
Masaru Uyeda Dr. Arnold L. Demain 《Journal of industrial microbiology & biotechnology》1987,1(6):341-347
Summary A cell-free extract from the thienamycin producer,Streptomyces cattleya, has been found to deacetylate the co-product,N-acetylthienamycin. The pH optimum of the reaction is 7.5. Due to the lability ofN-acetylthienamycin, we used thed andl forms of the synthetic substrateN-chloroacetylvaline. We found that the enzyme is anl-deacetylase, has a molecular weight of 58 000, is stable up to 40°C, acts optimally at 45°C, is stable at pH 5–8, is not activated by divalent metal ions and is inhibited by Hg++, Cu++ andp-chloromercuribenzoate. This is the first report of an extract from a carbapenem producer which carries out the deacetylation ofN-acetylthienamycin, suggesting that the acetylated derivative is a precursor of thienamycin.Abbreviations THM
thienamycin
- N-AcTHM
N-acetylthienamycin
- CFE
cell-free extract
- N-Cl-Ac-l-Val
N-chloroacetyl-l-valine
- N-Cl-Ac-d-Val
N-chloroacetyl-d-valine 相似文献
993.
Investigation of the cytotoxic active components of Michelia compressa afforded two new cytotoxic sesquiterpene lactones, michelenolide and micheliolide. Parthenolide, costunolide, santamarine, reynosin and liriodenine were also isolated and exhibited cytotoxic activity. The known sesquiterpene lactones, lanuginolide and dihydroparthenolide, were isolated but were not active. Two other new inactive sesquiterpene lactones, compressanolide and dihydroreynosin, were also obtained. The structures of michelenolide and micheliolide were confirmed by partial synthesis from parthenolide and the structure of compressanolide by partial synthesis from dihydroparthenolide. 相似文献
994.
Pseudomonas desmolytica S449B1 and Pseudomonas convexa S107B1 grown on n-propylbenzene oxidized n-propylbenzene to beta-phenylpropionic acid and benzoic acid by initial oxidation of the n-propyl side chain and the following beta-oxidation, respectively. The same strains also oxidized n-propylbenzene to 3-n-propylcatechol by initial oxidation of positions 2 and 3 of the aromatic nucleus. A ring fission product, 2-hydroxy-6-oxononanoic acid, was also isolated from the culture broth. Together with the results of oxygen uptake experiments, the data obtained suggested not only the existence of a reductive step to form 2-hydroxy-6-oxononanoic acid, but also the coexistence of two different pathways in the metabolism of n-propylbenzene by the strains used. 相似文献
995.
Yuji Maruyama Masaru Kusaka Jun Mori Akiko Horikawa Yoshikazu Hasegawa 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1979,164(2):121-127
An improved purification procedure is described for the simultaneous assay of endogenous choline and acetylcholine by pyrolysis gas chromatography, particularly for providing a simple and effective method for propionylation of choline in the presence of acetylcholine. The reaction was carried out in acetonitrile solution prepared by dissolving the evaporated residue of the supernatant of brain homogenate. Thus samples for propionylation were prepared without the use of ion-exchange chromatography. 相似文献
996.
Yoshio Inoue Shigeru Sase Riichiro Chûj Shunji Nagaoka Masaru Sogami 《Biopolymers》1979,18(2):373-382
The interactions between the protein, bovine plasma albumin, and surfactant, sodium dodecyl sulfate, have been studied by 13C-nmr spectroscopy at pH 5.4–6.8 in D2O solution. The 13C chemical shifts and the 13C spin-lattice relaxation time of the individual carbons of the surfactant were measured as a function of the molar ratio of the surfactant to albumin in order to analyze the surfactant-protein interaction and the molecular motion of the surfactant. It was found that in the region of initial binding of the surfactant to the high-affinity sites on the protein, both the surfactant head group and alkyl chain interact with the protein. With an excess of high-affinity sites at the beginning of the reaction, surfactant molecules are in a micellelike environment in which the surfactant's alkyl chains are associated with nonpolar groups of the protein. Even after the denaturation by many surfactant bindings, much of the secondary and higher structure seems to remain intact. 相似文献
997.
998.
Tomoki Sunobe Masaru Nakamura Yasuhisa Kobayashi Tohru Kobayashi Yoshitaka Nagahama 《Ichthyological Research》2005,52(1):27-32
The process of sex change in the gobiid fish Trimma okinawae was investigated by gonad histology and immunohistochemistry of two steroidogenic enzymes, P450 cholesterol-side-chain-cleavage (P450scc) and 3-hydroxysteroid dehydrogenase (3-HSD). Irrespective of sexual phase, gonads comprised both ovarian and testicular tissues. Females changed sex to male within 7 days, reverting again to female over an 11-day period. In each sexual phase of the females, the 2nd (2DF-M) and 4th (4DF-M) day after the initiation of sex change to male, the males, and 2nd (2DM-F), 4th (4DM-F), and 6th (6DM-F) days after the initiation of reversion from male to female, histological observations were made. In the ovary during the female, 2DF-M, 4DF-M, and 6DM-F phases, both vitellogenic and previtellogenic oocytes were present, but only previtellogenic oocytes were found in the other phases. The testis contained sperm in all phases, but sperm ducts were not visible in the female phase. In the ovary, P450scc immunoreactivity of interstitial cells was strongly or moderately detected, although weak in the male phase. In contrast, P450scc immunoreactivity in thecal cells was found in all but the male and 2DM-F phases. 3-HSD immunoreactive interstitial cells were detected in all phases, but only weakly so in the male and 2DM-F phases. 3-HSD immunoreactive thecal cells were observed in all stages without the male and 2DM-F and 4DM-F phases. In the testis, moderate P450scc and 3-HSD immunoreactivity was regularly found in the Leydig cells in all the phases. These results suggest that functional steroids including testosterone are produced in any sexual phases. 相似文献
999.
Establishment of a kit-negative cell line of melanocyte precursors from mouse neural crest cells 总被引:1,自引:0,他引:1
1000.
Kojima N Yamanaka M Ichiki S Sambongi Y 《Bioscience, biotechnology, and biochemistry》2005,69(7):1418-1421
Mutant strains of Escherichia coli lacking DsbA, DsbB, or DsbD (proteins required for disulfide bond formation in the periplasm) did not produce mitochondrial or chloroplast cytochromes c, as previously observed for bacterial ones. Unexpectedly, however, cytochrome c(555) (AA c(555)) from a hyperthermophile, Aquifex aeolicus, was produced in the E. coli periplasm without Dsb proteins, three times more than with them. These results indicate that the Dsb proteins are not necessarily required for AA c(555) production in E. coli, possibly because of hyperthermophilic origin compared with the others. 相似文献