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71.
Kenzo Yokozeki Shigeru Yamanaka Koichi Takinami Yoshio Hirose Atsuo Tanaka Kenji Sonomoto Saburo Fukui 《Applied microbiology and biotechnology》1982,14(1):1-5
Summary Lipase from Rhizopus delemar was immobilized by entrapment with photo-crosslinkable resin prepolymers or urethane prepolymers or by binding to various types of porous silica beads. The immobilized lipase preparations thus obtained were examined for their activity in converting olive oil to an interesterified fat (cacao butter-like fat), whose oleic acid moieties at 1- and 3-positions were replaced with stearic acid moieties, in the reaction solvent n-hexane. Although all of the immobilized preparations exhibited some activity, lipase adsorbed on Celite and then entrapped with a hydrophobic photo-crosslinkable resin prepolymer showed the highest activity, about 75% of that of lipase simply adsorbed onto Celite. Entrapment markedly enhanced the operational stability of lipase.Dedicated to Professor H. Holzer, Freiburg University, on his 60th birthday (June 13, 1981) 相似文献
72.
Cultured crown gall cells were irradiated with gamma rays toinduce mutation in indoleacetic acid biosynthesis. The irradiatedcells were plated on a selection medium which contained auxin.Mutant cells adapted to selection media were characterized asauxin-heterotrophic and auxin-resistant cell lines. The auxin-heterotrophicmutants contained little auxin, whereas the auxin-resistantand -autotrophic mutants contained large amounts of auxin evenwhen cultured with 0.3 ppm of 2,4-dichlorophenoxyacetic acid.Each mutant cell line contained as much octopine as its parentalcells. The mutation rate was calculated as in the order of 108. (Received May 6, 1980; ) 相似文献
73.
Masatoshi Takeichi Tadao Atsumi Chikako Yoshida Kazuko Uno T.S. Okada 《Developmental biology》1981,87(2):340-350
The specificity of adhesion between embryonal carcinoma cells and fibroblastic cells of various origins was studied. Embryonal carcinoma cells have intercellular adhesion sites requiring Ca2+ (CDS). These sites were found to be sensitive to proteases but resistant to them in the presence of Ca2+. CDS with a similar protease sensitivity is present in fibroblastic cells. When embryonal carcinoma cells of different lines were mixed, they adhered to each other nonselectively by CDS. Nonselective adhesion by CDS occurred also between fibroblastic cells of various lines. When embryonal carcinoma and fibroblastic cells were mixed, they preferentially adhered to homotypic cells. Fab fragments of antibodies raised against F9 cells (a nullipotent line of embryonal carcinoma) inhibited the adhesion between embryonal carcinoma cells but not between fibroblastic cells. This inhibitory activity of Fab was absorbed with embryonal carcinoma cells with CDS, but not with fibroblastic cells with CDS or embryonal carcinoma cells from which CDS was experimentally removed. SDS-polyacrylamide gel electrophoresis of radioiodinated cell surface proteins showed that the presence of a 140K-dalton component correlated with the presence of CDS in embryonal carcinoma cells, while the presence of a 150K-dalton component correlated with the presence of CDS in fibroblastic cells. These results suggest that CDS in embryonal carcinoma and fibroblastic cells comprise distinct molecules. 相似文献
74.
M Kitada K Igarashi S Hirose H Kitagawa 《Biochemical and biophysical research communications》1979,87(2):388-394
Both NADPH- and ascorbic acid-dependent lipid peroxidations were inhibited by spermine, the degree of inhibition being greater with the former peroxidation. The effective concentration of spermine required for inhibition was higher when larger amounts of microsomes were used. However, the activities of NADPH-cytochrome c reductase and NADPH-peroxidase were not influenced by spermine. These results suggest that spermine inhibits lipid peroxidation by binding to phospholipids in the microsomes. 相似文献
75.
K Igarashi K Kashiwagi R Aoki M Kojima S Hirose 《Biochemical and biophysical research communications》1979,91(2):440-448
In the presence of polyamines, the fidelity of protein synthesis in a wheat germ cell-free system was increased significantly, while it was increased slightly in an cell-free system. The effective concentration of polyamines for the increase in fidelity of protein synthesis was nearly equal to that for the stimulation of protein synthesis in a wheat germ cell-free system. 相似文献
76.
K Igarashi M Tanaka K Eguchi S Hirose 《Biochemical and biophysical research communications》1978,83(1):274-280
It is shown that rat liver isoleucyl-tRNA formation in the presence of Mg2+ is inhibited by poly(G), poly(I) or ribosomes and that this inhibition is prevented by polyamines. The inhibition is found to be noncompetitive with respect to tRNA. 相似文献
77.
K Igarashi H Kumagai Y Watanabe N Toyoda S Hirose 《Biochemical and biophysical research communications》1975,67(3):1070-1077
The activities of ribonucleases (RNase HS and RNase A), which hydrolyze ribonucleic acid at linkages attached to pyrimidine nucleotides were stimulated by polyamines, while the activities of ribonucleases (RNase T1 and RNase M), which attack ribonucleic acid at linkages attached to purine nucleotides were not influenced by polyamines. In the presence of polyamines, the cleavage of C5′-O-P linkages adjacent to cytosine nucleotide was stimulated, while the cleavage of C5′-O-P linkages adjacent to uracil nucleotides was inhibited slightly. The effect of polyamines on the activities of ribonucleases occured through the binding of the polyamines to nucleic acid. 相似文献
78.
79.
Phosphorylation of mononucleotides and formation of cytidine 5''-diphosphate-choline and sugar nucleotides by respiration-deficient mutants of yeasts. 下载免费PDF全文
Respiration-deficient mutants (Rho-, petite) of Saccharomyces carlsbergensis were obtained by treatment with trypaflavin (euflavine). Dried cells of these mutants phosphorylated mononucleotides to their triphosphates and further formed not only cytidine 5'-diphosphate-choline, but also sugar nucleotides, such as uridine 5'-diphosphate-glucose, guanosine 5'-diphosphate-mannose, etc. The activities were the same or slightly greater than those of the wild strain. These results showed that energy (adenosine 5'-triphosphate) necessary for phosphorylation of mononucleotides was sufficiently supplied by the glycolysis system. 相似文献
80.
Hajime Sakaguchi Hiromi Hagiwara Yoshihiro Fukumori Yutaka Tamaura Minoru Funaki Shigehisa Hirose 《FEMS microbiology letters》1993,107(2-3):169-173
Abstract The magnetic bacterium Magnetospirillum magnetotacticum prefers a microaerobic habitat and should be able to sense oxygen. Therefore, the bacterium was cultured under atmospheres containing 0–5% O2 and analyzed for oxygen-dependent changes in the levels of its protein components by sodium dodecyl sulfate-polyccrylamide gel electrophoresis (SDS-PAGE). The analysis revealed a marked anaerobic induction of a 140-kDa protein, which was suppressed when M. magnetotacticum was switched from microaerobic (<1% O2 ) to aerobic (>1% O2 ) growth conditions. Although its function remains to be determined, the 140-kDa protein may serve as a useful tool to gain insight into the physiology of the organism. 相似文献