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排序方式: 共有937条查询结果,搜索用时 15 毫秒
1.
Kitamura Akira; Matsui Kenji; Kajiwara Tadahiko; Hatanaka Akikazu 《Plant & cell physiology》1992,33(4):493-496
C6-Aldehydes emitted from intact tea leaves were analyzed quantitatively.Emission of the aldehydes increased temporarily in mid-May whenenzymatic activities involved in aldehyde formation from lipidsbegan to increase. Levels of C6-aldehydes in tea leaves alsoincreased temporarily. However, the accumulated C6-aldehydesdid not always correspond to emitted ones. (Received December 1, 1991; Accepted March 18, 1992) 相似文献
2.
Effect of the recombinant vaccinia viruses that express HTLV-I envelope gene on HTLV-I infection. 总被引:11,自引:0,他引:11 下载免费PDF全文
H Shida T Tochikura T Sato T Konno K Hirayoshi M Seki Y Ito M Hatanaka Y Hinuma M Sugimoto et al. 《The EMBO journal》1987,6(11):3379-3384
The human T-lymphotropic virus type I (HTLV-I) is etiologically linked to adult T-cell leukemia (ATL). To develop a vaccine against ATL, we constructed recombinant vaccinia viruses containing the envelope gene of HTLV-I in the vaccinia virus hemagglutinin (HA) gene, a new site where foreign genes can be inserted. A single inoculation of the recombinant virus induced antibodies to the env proteins of HTLV-I in rabbits and had a protective effect against HTLV-I infection. 相似文献
3.
The effects of epidermal growth factor (EGF) and transforming growth factor beta (TGF beta) on the growth of A431 epidermoid carcinoma cells were studied. Whereas the monolayer growth of A431 cells was inhibited by EGF, it was stimulated by TGF beta. Contrary to the effects on the monolayer growth, EGF stimulated the soft agar growth of A431 cells. The stimulatory effects of TGF beta on the anchorage-dependent growth were antagonized by EGF and those of EGF on anchorage-independent growth were antagonized by TGF beta. These results suggest that both factors not only convey the proliferative signals to A431 cells but also induce phenotypic changes, resulting in a preference for either anchorage-dependent or anchorage-independent growth. Moreover, as the stimulatory effects of EGF on the soft agar growth of A431 cells paralleled its reported stimulatory effects on their in vivo growth, it is also suggested that in vivo responses of cells to certain growth factors may correlate better with their responses in soft agar culture than with those in monolayer culture. 相似文献
4.
Noriaki Murakami Yoshiyuki Tanaka Kunio Takishima Yuzo Minobe Makoto Matsuoka Sei-Ichiro Kiyota Shin-ichi Hatanaka Katsuhiro Sakano 《Journal of plant research》1990,103(4):419-434
We isolated the small subunit of ribulose-1, 5-bisphosphate carboxylase/oxygenase (RuBisCO SSu) from a fern,Asplenium cataractarum and determined its 34 N-terminal amino acid sequence. We obtained a cDNA clone that contains the entire coding region of
the SSu from the same fern species, using synthetic oligonucleotide probes derived from the above amino acid sequence. It
contains a 525 bp open reading frame capable of coding for a polypeptide with 174 amino acids, 31 bp 5′-and 206 bp 3′-noncoding
regions. It was also elucidated that the precursor to the SSu contains a transit peptide of 53 amino acid residues and a mature
protein of 121 residues. We compared the deduced amino acid sequence of the fern SSu with those of 11 other vascular plant
species (including gymnosperms, monocots and dicots). As low as 55% homology was observed between those of a fern and seed
plants. Constancy of the amino acid substitution rate in RuBisCO SSu was supported by our relative rate test. Amino acid substitution
rate per year per site for RuBisCO SSu was calculated to be 0.81×10−9 assuming that the separation between pteridophytes and seed plants arose 380 million years ago. 相似文献
5.
Immunohistochemical localization of Na+-dependent glucose transporter in rat jejunum 总被引:2,自引:0,他引:2
Kuniaki Takata Toshiko Kasahara Michihiro Kasahara Osamu Ezaki Hiroshi Hirano 《Cell and tissue research》1992,267(1):3-9
Summary Glucose is actively absorbed via a Na+-dependent active glucose transporter (Na-GT) in the small intestine. We raised a polyclonal antibody against the peptide corresponding to amino acids 564–575 of rabbit intestinal Na-GT, and localized it immunohistochemically in the rat jejunum. By means of immunofluorescence staining, Na-GT was located at the brush border of the absorptive epithelial cells of the intestinal villi. Electron-microscopic examination showed that Na-GT was localized at the plasma membrane of the apical microvilli of these cells. Little Na-GT was found at the basolateral plasma membrane. Along the crypt-villus axis, all of the absorptive epithelial cells in the villus were positive for Na-GT. In addition to the brush border staining, the supranuclear positive staining, which was shown to be the Golgi apparatus by use of electron microscopy, was seen in cells located between the base to the middle of the villus. Cells in crypts exhibited little or no staining for Na-GT. Goblet cells scattered in the intestinal epithelium were negative for Na-GT staining. These observations show that Na-GT is specific to the apical plasma membrane of the absorptive epithelial cells, and that the onset of Na-GT synthesis may occur near the crypt-villus junction. 相似文献
6.
N Ishida Y Aoyama R Hatanaka Y Oyama S Imajo M Ishiguro T Oshima H Nakazato T Noguchi U S Maitra 《Biochemical and biophysical research communications》1988,155(1):317-323
Genes for lanosterol 14-demethylase, cytochrome P450(14DM), and a mutated inactive cytochrome P450SG1 were cloned from S. cerevisiae strains D587 and SG1, respectively. A single nucleotide change resulting in substitution of Asp for Gly-310 of cytochrome P450(14DM) was found to have occurred in cytochrome P450SG1. In this protein the 6th ligand to heme iron is a histidine residue instead of a water molecule, which may be the ligand for the active cytochrome P450(14DM). Molecular models of the active sites of the cytochrome P450(14DM) and cytochrome P450SG1 were built by computer modeling on the basis of the known structure of that of cytochrome P450CAM whose crystallographic data are available. The mechanisms which may cause a histidine residue to gain access to the heme iron are discussed. 相似文献
7.
K Hatanaka H Tanishita H Ishibashi-Ueda A Yamamoto 《Biochimica et biophysica acta》1986,878(3):440-445
Approximately 70% of the W/WV mice lacking mast cells due to a genetic defect showed hypertriglyceridemia combined with hypercholesterolemia. Increases of various magnitudes in chylomicrons, very-low-density lipoprotein, and intermediate-density lipoprotein were observed in the plasma of W/WV mice compared to those in the plasma of congenic normal mice. The increase in these lipoproteins was seen even in normolipidemic W/WV mice. Activities of both lipoprotein lipase and hepatic triacylglycerol lipase in the plasma after heparin injection were markedly lower in the W/WV mice than in the congenic normal mice, although activities of both lipoprotein lipase in the heart and adipose tissue and hepatic triacylglycerol lipase in the liver were not decreased. These results suggest that the W/WV mice have genetic defects in one or more of the following: secretion of both lipases from their synthesising cells, transport to the endothelium, and anchoring to the endothelial surface. Heparin deficiency in these mice may be responsible for the impairment and, thereby, may partially contribute to the hyperlipidemia. 相似文献
8.
The rates of hydrolysis of the ester, amide and anilide substrates of p-guanidino-L-phenylalanine (GPA) by Streptomyces griseus trypsin (S. griseus trypsin) were compared with those of arginine (Arg) substrates. The specificity constant (kcat/km) for the hydrolysis of GPA substrates by the enzyme was 2-3-times lower than that for arginine substrates. The kcat and Km values for the hydrolysis of N alpha-benzoyl-p-guanidino-L-phenylalanine ethyl ester (Bz-GPA-OEt) by S. griseus trypsin are in the same order of magnitude as those of N alpha-benzoyl-L-arginine ethyl ester (Bz-Arg-OEt), although both values for the former when hydrolyzed by bovine trypsin are higher by one order of magnitude than those for the latter. The specificity constant for the hydrolysis of Bz-GPA-OEt by S. griseus trypsin is much higher than that for N alpha-benzoyl-p-guanidino-L-phenylglycine ethyl ester (Bz-GPG-OEt). As with the kinetic behavior of bovine trypsin, low values in Km and kcat were observed for the hydrolysis of amide and anilide substrates of GPA by S. griseus trypsin compared with those of arginine substrates. The rates of hydrolysis of GPA and arginine substrates by S. griseus trypsin are about 2- to 62-times higher than those obtained by bovine trypsin. Substrate activation was observed with S. griseus trypsin in the hydrolysis of Bz-GPA-OEt as well as Bz-Arg-OEt, whereas substrate inhibition was observed in three kinds of N alpha-protected anilide substrates of GPA and arginine. In contrast, no activation by the amide substrate of GPA could be detected with this enzyme. 相似文献
9.
M Hatanaka T Sasaki T Kikuchi T Murachi 《Archives of biochemistry and biophysics》1985,242(2):557-562
Porcine calpains (Ca2+-dependent cysteine proteinases) I and II, which had been purified each to a homogeneous state, were found to hydrolyze specifically carboxyl-terminal amide of substance P and several other biologically active peptidyl amides. This amidase-like activity was demonstrated both by determining released ammonia and by separating products on high-performance liquid chromatography followed by amino acid analysis. The calpain-catalyzed deamidation of substance P occurred exclusively at the carboxyl-terminal amide, leaving the side-chain glutamine intact. Enkepharinamide and MSH-release inhibiting factor were scarcely deamidated. Calpains I and II showed similar specificities for these amide substances and similar profiles of inhibitions by various protease inhibitors, but distinctly different Ca2+ requirements. The specificity constants, kcat/Km, for substance P were found to be three to four orders of magnitude higher than those for the synthetic substrates. 相似文献
10.
beta-D-Glucosidase was purified from seeds of Japanese cycad by dialysis, chromatography on CM-Sepharose CL-6B, gel filtration on Biogel P-200, and chromatofocusing. By chromatofocusing, beta-D-glucosidase was separated into four components whose isoelectric points were in a very narrow range (7.43-7.68). All these components were glycoproteins. The main component (pI = 7.59) was homogeneous on gel isoelectric focusing, and was crystallized from ammonium sulfate solution. The molecular weight of the crystalline preparation was determined to be 137,000 by gel filtration, and 67,000 by sodium dodecylsulfate polyacrylamide gel electrophoresis, indicating the main component was composed of two subunits with the same molecular weight. The amino acid composition and sugar content of the main component were also determined. All four components hydrolyzed not only o-nitrophenyl beta-D-glucopyranoside but also o-nitrophenyl beta-D-galactopyranoside, o-nitrophenyl beta-D-fucopyranoside, and o-nitrophenyl beta-D-xylopyranoside. Hydrolysis rates of each substrate by the four components were quite similar. Mixed substrate experiments using crystalline preparation proved that a single active site was responsible for the hydrolysis of these substrates. 相似文献