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61.
K Murata Y Fukuda M Shimosaka K Watanabe T Saikusa A Kimura 《Applied and environmental microbiology》1985,50(5):1200-1207
The gene responsible for the methylglyoxal resistance of Saccharomyces cerevisiae was cloned, and its phenotypic characteristics were investigated. S. cerevisiae cells with the gene could accumulate large amounts of glutathione in the medium and should remarkably high resistance to various toxic compounds such as methylglyoxal, tetramethylthiuram disulfide, iodoacetamide, and heavy-metal ions. The gene was also expressed in Escherichia coli cells, and the resistance of E. coli cells to toxic compounds also increased as observed for S. cerevisiae cells. The phenotypic characteristics of the gene were applicable to the selection of the transformants of wild-type yeast strains having no genetic markers. 相似文献
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Effects of glucagon on the redox states of cytochromes in mitochondria in situ in perfused rat liver 总被引:1,自引:0,他引:1
S Kimura T Suzaki S Kobayashi K Abe E Ogata 《Biochemical and biophysical research communications》1984,119(1):212-219
The effects of glucagon on the respiratory function of mitochondria in situ were investigated in isolated perfused rat liver. Glucagon at the concentrations higher than 20 pM and cyclic AMP (75 microM) stimulated hepatic respiration, and shifted the redox state of pyridine nucleotide (NADH/NAD) in mitochondria in situ to a more reduced state as judged by organ fluorometry and beta-hydroxybutyrate/acetoacetate ratio. The organ spectrophotometric study revealed that glucagon and cyclic AMP induced the reduction of redox states of cytochromes a(a3), b and c+c1. Atractyloside (4 micrograms/ml) abolished the effects of glucagon on these parameters and gluconeogenesis from lactate. These observations suggest that glucagon increases the availability of substrates for mitochondrial respiration, and this alteration in mitochondrial function is crucial in enhancing gluconeogenesis. 相似文献
64.
Adrenocorticotropic hormone-mediated changes in rat adrenal mitochondrial phospholipids 总被引:1,自引:0,他引:1
We examined the subcellular localization of ACTH (adrenocorticotropic hormone)-induced changes in adrenal phospholipids using dexamethasone-treated rats. In adrenal mitochondrial fraction, ACTH significantly enhanced both concentrations and contents of phosphatidylinositol (37%), phosphatidylcholine (22%), and phosphatidylethanolamine (20%). Other mitochondrial phospholipids including cardiolipin did not change upon administration of ACTH. In adrenal plasma membrane, endoplasmic reticulum, and peroxisomes, no increase in phospholipids was observed. The ACTH-induced increases in mitochondrial phosphatidylinositol, phosphatidylcholine, and phosphatidylethanolamine were specific to adrenal among tissues tested. These changes were observed specifically in cortical cells rather than medulla. Nonsteroidogenic ACTH fragments and related peptides were unable to induce the change in adrenal mitochondrial phospholipids. From the dose-response profile with ACTH, the changes in mitochondrial phospholipids were closely related to ACTH-dependent stimulation of steroidogenesis. Furthermore, in vitro treatment with cyclic AMP enhanced both concentrations and contents of mitochondrial phosphatidylinositol, phosphatidylcholine, and phosphatidylethanolamine similar to those by the in vivo administration of ACTH. Both in vivo and in vitro experiments revealed that the hormone-induced changes in mitochondrial phospholipids were sensitive to a protein-synthesis inhibitor, cycloheximide. However, aminoglutethimide and cytochalasin B, which strongly inhibited the hormone-induced formation of corticosterone, did not affect the increases in mitochondrial phospholipids. These results suggest that the hormone-induced increases in these phospholipids occur between ACTH-mediated ribosomal protein synthesis and corticosterone formation. 相似文献
65.
An anti-I-Ab monoclonal antibody, designated K14.83-11, was produced in a fusion between SP 2/0 Ag-14 myeloma cells and spleen cells from a B10.D2/n mouse primed in vivo against C57BL/10. Unlike other anti-I-Ab monoclonal antibodies thus far described, K14.83-11 was found to have a combination of features involving specificity, isotype, and function, unique among existing anti-I-A reagents. K14.83-11 exhibited a strong binding to the I-Ab gene product, with only slight cross-reactivity to the I-Ap/q family of allelic products and no reactivity towards I-Ak,d. When analyzed for isotype, K14.83-11 was found to be of a rare IgG3 isotype. With respect to biologic activity, K14.83-11 not only failed to produce the expected inhibition of specific anti-I-Ab T cell reactivity in vitro, but instead produced a striking enhancement of T cell responses against the I-Ab gene product. The possible relationship of IgG isotype and function was suggested when the immunoenhancing effect of K14.83-11 on reactive T lymphocytes was reversed to that of suppression with highly purified F(ab)2 fragments obtained by pepsin digestion. 相似文献
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Akira Inokuchi Yasunobu Tomida Chizuko Yanaihara Ryogo Yui Yutaka Oomura Hiroshi Kimura Takanobu Hase Tomoaki Matsumoto Noboru Yanaihara 《Cell and tissue research》1986,246(1):71-75
Summary Immunohistochemically, nerve fibers and terminals reacting with anti-N-terminal-specific but not with anti-C-terminal-specific glucagon antiserum were observed in the following rat hypothalamic regions: paraventricular nucleus, supraoptic nucleus, anterior hypothalamus, arcuate nucleus, ventromedial hypothalamic nucleus and median eminence. Few fibers and terminals were demonstrated in the lateral hypothalamic area and dorsomedial hypothalamic nucleus. Radioimmunoassay data indicated that the concentration of gut glucagon-like immunoreactivity was higher in the ventromedial nucleus than in the lateral hypothalamic area. In food-deprived conditions, this concentration increased in both these parts. This was also verified in immunostained preparations in which a marked enhancement of gut glucagon-like immunoreactivity-containing fibers and terminals was observed in many hypothalamic regions. Several immunoreactive cell bodies were found in the ventromedial and arcuate nuclei of starved rats. Both biochemical and morphological data suggest that glucagon-related peptides may act as neurotransmitters or neuromodulators in the hypothalamus and may be involved in the central regulatory mechanism related to feeding behavior and energy metabolism. 相似文献
69.
Shark (Prionace glauca) elastoidin: characterization of its collagen as [alpha 1(E)]3 homotrimers 总被引:1,自引:0,他引:1
S Kimura Y Uematsu Y Miyauchi 《Comparative biochemistry and physiology. B, Comparative biochemistry》1986,84(3):305-308
A new type of collagen was isolated from elastoidin of great blue shark by limited pepsin digestion. The collagen alpha chain of elastoidin, designated alpha 1(E), was very similar in electrophoretic and chromatographic behavior and amino acid composition to shark skin alpha 1(I) chain, but they were genetically-distinct on the basis of CNBr-peptide maps. The collagen molecule of elastoidin was shown to be an [alpha 1(E)]3 homotrimer. 相似文献
70.