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1.
Atsunori Kashiwagi Kazuyuki Sasaki Tamio Noguchi Takehiko Tanaka 《Biochimica et Biophysica Acta (BBA)/General Subjects》1979,582(2):221-233
A factor responsible for stimulating an increase in ornithine decarboxylase activity in the liver of mice was found in tumor cell-free ascites fluid of mice 3 days after inoculation of tumor cells. The factor was purified about 70-fold in 25% yield from tumor cell-free ascites fluid. As little as 1 μg of protein of purified fraction, injected intraperitoneally into normal mice, significantly increased the activity of ornithine decarboxylase in the liver. The most active preparation of the factor formed two major protein bands on analytical polyacrylamide gel electrophoresis and both these bands stained with periodic acid-Schiff's reagent. The factor was a heat-labile, alkaline-stable, acidic protein with a molecular weight of more than 300 000. It was inactivated by treatment with 10 mM dithiothreitol, 5M urea, pronase or mixed glycosidase, but was stable on treatment with DNAase, RNAase or neuraminidase. 相似文献
2.
Rates for the reaction of nitric oxide with several ferric heme proteins and model compounds have been measured. The NO combination rates are markedly affected by the presence or absence of distal histidine. Elephant myoglobin in which the E7 distal histidine has been replaced by glutamine reacts with NO 500-1000 times faster than do the native hemoglobins or myoglobins. By contrast, there is no difference in the CO combination rate constants of sperm whale and elephant myoglobins. Studies on ferric model compounds for the R and T states of hemoglobin indicate that their NO combination rate constants are similar to those observed for the combination of CO with the corresponding ferro derivatives. The last observation suggests that the presence of an axial water molecule at the ligand binding site of ferric hemoglobin A prevents it from exhibiting significant cooperativity in its reactions with NO. 相似文献
3.
Human mononuclear phagocyte activation antigens 总被引:2,自引:0,他引:2
R F Todd I F Mizukami S D Vinjamuri R D Trochelman W W Hancock D Y Liu 《Blood cells》1990,16(1):167-79; discussion 180-2
Activation of mononuclear phagocytes causes changes in plasma membrane composition that include the expression of surface antigens and receptors. Monoclonal antibody technology has made it possible to identify and characterize newly expressed surface antigens. Among these "activation antigens" is a glycoprotein, Mo3, which (among hematopoietic cells) is selectively expressed by human mononuclear phagocytes that have been exposed to inflammatory factors in vitro and in vivo. Progress toward a functional and structural analysis of Mo3 is described. 相似文献
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5.
Mizukami Hajime; Terao Toshimitsu; Amano Akemi; Ohashi Hiromu 《Plant & cell physiology》1986,27(4):645-650
Cultured cells of Gardenia jasminoides produced both salicinand isosalicin from exogenously supplied salicyl alcohol. Theglucosylation activity of the cells was highest in the exponentialphase of growth and ca. 70% of the added substrate was convertedto the glucosides within 4 days. The rate of glucosylation wasalso dependent on the medium composition such as auxin and sucroseconcentrations. The ratio of salicin to isosalicin formed fromsalicyl alcohol was influenced by the growth stage of the culturedcells. Salicin was converted to isosalicin when exogenouslyadded to the culture. (Received October 11, 1985; Accepted March 10, 1986) 相似文献
6.
Gene structure of a major form of phenobarbital-inducible cytochrome P-450 in rat liver 总被引:19,自引:0,他引:19
Y Suwa Y Mizukami K Sogawa Y Fujii-Kuriyama 《The Journal of biological chemistry》1985,260(13):7980-7984
The gene structure of cytochrome P-450b, a major form of phenobarbital-inducible cytochrome P-450 in rat livers was elucidated by sequence analysis of the cloned genomic DNAs and was compared with the previously determined gene structures of cytochrome P-450e, a minor form of phenobarbital-inducible cytochrome P-450 and two forms of 3-methylcholanthrene-inducible cytochrome P-450 (P-450c and -d). The gene for cytochrome P-450b is 23 kilobase pairs (kb) long and is separated into 9 exons by 8 intervening sequences. This gene structure is very similar to that of cytochrome P-450e except for the first intron, the first intron being much longer in cytochrome P-450b gene (approximately 12 kb) than in cytochrome P-450e gene (3.2 kb), but differs greatly from the gene structures of two 3-methylcholanthrene-inducible cytochrome P-450s as pointed out previously (Sogawa, K., Gotoh, O., Kawajiri, K. & Fujii-Kuriyama, Y. (1984) Proc. Natl. Acad. Sci. U.S.A. 81, 5066-5070). The nucleotide sequences in all 9 exons and their flanking regions in introns show very close homology between the two phenobarbital-inducible cytochrome P-450 genes. Forty base substitutions are found in approximately 1900 nucleotides of all exonic sequences, and 15 of them result in 14 amino acid replacements. These base substitutions occur in relatively limited regions of the gene sequences. Most of them are found in exons 6, 7, 8, and 9, most frequently in exon 7 as described previously (Mizukami, Y., Sogawa, K., Suwa, Y., Muramatsu, M. & Fujii-Kuriyama, Y. (1983) Proc. Natl. Acad. Sci. U.S.A. 80, 3958-3962). The close sequence homology between the two phenobarbital-inducible cytochrome P-450 genes is also found to extend to the promoter region with one notable exception. The simple repeated sequences of (CA)n which is present at -254 position in cytochrome P-450e gene is also observed at the equivalent position in cytochrome P-450b gene, but the repetitiveness is greatly reduced in cytochrome P-450b gene ((CA)5 for P-450b versus (CA)19 for P-450e), and this may somehow be related to the difference in the level of cytochrome P-450b and P-450e in the inductive phase of phenobarbital administration. 相似文献
7.
8.
Summary Antimicrotubule agents, colchicine, vinblastine, and griseofulvin, induced conspicuous morphological anomalies inBryopsis plumosa. First, following cessation of protoplasmic streaming within 15 minutes, elongation stopped in a few hours. Second, innumerable protrusions or new growth points generated over the cell flank in a few days. Similar phenomena were observed in the cells which were subjected to high pressure or low temperature both of which are known to disrupt microtubule.These phenomena were investigated with light and electron microscopy. It is suggested that inhibition of microtubule dependent protoplasmic streaming which may function as an intracellular transport system causes such morphological anomalies. 相似文献
9.
10.
Peter L. Pingerelli Hiroshi Mizukami Monica J. Mooney Alice L. Schlaepfer 《The protein journal》1989,8(2):183-196
S100b is a calcium-binding protein that will bind to many calmodulin target molecules in a Ca2+-dependent manner. In order to study the Ca2+-dependent binding properties of S100b, its interaction with a calmodulin antagonist, trifluoperazine (TFP), was investigated using [19F]- and [1H]-NMR and UV-difference spectroscopy. It was estimated from [19F]-NMR that in the absence of Ca2+, thek 1/2 value of TFP was 130 µM, while itsk 1/2 value decreased to 28 µM in the presence of Ca2+. The addition of KCl was not antagonistic to the Ca2+-dependent interaction of TFP to S100b. The chemical exchange rate of TFP with Ca2+-bound S100b was estimated to be 9×102 sec?1. By comparison with TFP-calmodulin exchange rates, it is suggested that the TFP-binding site on S100b is structurally different from its binding sites on calmodulin. Proton NMR resonance broadening in the range 6.8–7.2 ppm, corresponding to phenylalanine nuclei of S100b, indicates that these residues may be involved in TFP binding. Addition of Ca2+ to a 1:1 mixture of S100b and TFP resulted in a red-shifted UV-difference spectrum, while no significant difference spectrum was detected when Mg2+ was added to a S100b-TFP solution. Thus, we suggest that Ca2+ induces the exposure of a hydrophobic domain on S100b containing one or more phenylalanine residues that will bind TFP but that this domain is different from the hydrophobic domain on calmodulin. 相似文献