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31.
Nichola J. K. Hole Edmundo Lamoyi Masanori Komatsu Nagaradona Harindranath Glendowlyn O. Young-Cooper Rose G. Mage 《Immunogenetics》1988,28(2):99-107
In order to investigate linkage, we used serum allotypes of the two rabbit C
isotypes and restriction fragment length polymorphisms (RFLPs) of the genes for V
, C
, and T-cell receptor C
. The inheritance of these genetic markers was studied through backcross and F2 matings. Southern analysis and hybridization of genomic DNA with a C probe detected a 5 kb Pst I fragment linked to expression of the K2bas1 allotype and the presence of the 1b
bas gene and a 6.6 kb Pst I fragment linked to the expression of the K1b9 allotype, the presence of the 2
bas2 gene and lack of expression of the K2bas1 allotype. A V probe detected a 1.3 kb Eco RI fragment linked to the presence of the 1b
bas gene and expression of the K2bas1 allotype. In contrast, the 9 or 14 kb Eco RI RFLP (C
a or C
b) detected with a Tcr
chain probe segregated independently from C allotypes and RFLPs. It has previously been found that C and C
are also unlinked in man, whereas in the mouse they are linked at a distance of 8 centimorgans. 相似文献
32.
We tested the effect of oleic acid on oxidative phosphorylation and free fatty acid composition in rat brain slices simultaneously to investigate the relationship between the change in respiratory control ratio and the uptake of oleic acid in the brain mitochondria. The uncoupling of mitochondria was observed when the ratio of oleic acid to stearic acid in the free fatty acid fraction was nearly doubled, but was not recovered even by the addition of fatty acid-free bovine serum albumin. The data suggest that the intactness of oxidative phosphorylation of brain mitochondria is maintained by the precise control of the free fatty acid composition in the mitochondrial membranes. 相似文献
33.
Both Km and Vmax values of cytochrome c oxidase for cytochrome c were elevated in oleic acid-incorporated mitochondria, whereas the amount of oleic acid incorporated into submitochondrial particles was smaller than that into mitochondria and the fatty acid had little effect on the enzyme activity. The degree of change in the bulk membrane fluidity was, however, almost the same in mitochondria and submitochondrial particles. Solubilized cytochrome c oxidase was insensitive to the effect of oleic acid. Oleic acid may act as a modifier of the interaction between cytochrome c oxidase and membrane lipids. 相似文献
34.
Hiroshi Yanagawa Yoko Ogawa Kiyotsugu Kojima Masahiko Ito 《Origins of life and evolution of the biosphere》1988,18(3):179-207
We have developed experimental approaches for the construction of protocellular structures under simulated primitive earth conditions and studied their formation and characteristics. Three types of envelopes; protein envelopes, lipid envelopes, and lipid-protein envelopes are considered as candidates for protocellular structures. Simple protein envelopes and lipid envelopes are presumed to have originated at an early stage of chemical evolution, interaction mutually and then evolved into more complex envelopes composed of both lipids and proteins.Three kinds of protein envelopes were constructedin situ from amino acids under simulated primitive earth conditions such as a fresh water tide pool, a warm sea, and a submarine hydrothermal vent. One protein envelope was formed from a mixture of amino acid amides at 80 °C using multiple hydration-dehydration cycles. Marigranules, protein envelope structures, were produced from mixtures of glycine and acidic, basic and aromatic amino acids at 105 °C in a modified sea medium enriched with essential transition elements. Thermostable microspheres were also formed from a mixture of glycine, alanine, valine, and aspartic acid at 250 °C and above. The microspheres did not form at lower temperatures and consist of silicates and peptide-like polymers containing imide bonds and amino acid residues enriched in valine. Amphiphilic proteins with molecular weights of 2000 were necessary for the formation of the protein envelopes.Stable lipid envelopes were formed from different dialkyl phospholipids and fatty acids.Large, stable, lipid-protein envelopes were formed from egg lecithin and the solubilized marigranules. Polycations such as polylysine and polyhistidine, or basic proteins such as lysozyme and cytochromec also stabilized lipid-protein envelopes. 相似文献
35.
The kinetics of cleavage of the phage phi 80 cI repressor by Escherichia coli RecA protein were studied. The rate of cleavage in the presence of single-stranded DNA (ssDNA) and either adenosine 5'-O-(3-thiotriphosphate) (ATP gamma S), ATP or dATP is very low in the first hour at 37 degrees C and then increases sharply as incubation continues. The initial rate of cleavage of the repressor is greatly increased by incubating the RecA protein with ssDNA prior to addition of ATP gamma S and the repressor. However, when ATP gamma S is present during preincubation of RecA protein with ssDNA, the stimulatory effect of preincubation is greatly reduced. This difference in the effect of preincubation in two different conditions can be explained by formation of RecA-ssDNA-ATP gamma S complexes with different activities for cleavage of the repressor. The active complex is formed by binding of ATP gamma S to a complex of RecA protein and ssDNA. However, when the RecA protein binds to ATP gamma S prior to its binding to ssDNA, the resulting complex has no or only very weak cleavage activity toward the repressor. 相似文献
36.
Morikawa Hiromichi; Hayashi Yasuyuki; Hirabayashi Yasuzi; Asada Masanori; Yamada Yasuyuki 《Plant & cell physiology》1988,29(1):189-193
Protoplasts isolated from cultured cells of Coptis japonicaand Euphorbia millii were electrically fused using platinummicroelectrodes. The process involved two stages, cellular andvacuolar fusion, which are characterized respectively by transientwrinkling of the membrane and the formation of a dark-red precipitate. (Received June 12, 1987; Accepted October 13, 1987) 相似文献
37.
The effects of three physical parameters upon protoplast electrofusionwere studied using protoplasts from cultured cells of Coptisjaponica and Euphorbia millii. The osmotic potential of themedium did not appreciably affect the AC-field-induced protoplast-pairformation, but significantly influenced the fusion process ofthe paired protoplasts in response to DC pulses. The optimumosmotic potential was 0.55 to 0.60 Osm/kg H2O in our system.The density of the medium markedly influenced both pair formationand fusion process. The optimum density was 1.13 to 1.14 g/cm3,and at this density the yield of the fused protoplasts increasedto more than twice that of the control (1.10 g/cm3). Hydrophiliccoating of the bottom surface of the chamber with Gellan gumor polyacrylamide gel was also effective for both pair formationand the fusion process, while coating with hydrophobic siliconewas entirely inhibitory. Possible interpretations of the effectsof these physical parameters upon protoplast electrofusion arepresented.
1Permanent address: Biochemical Research Laboratories, KanegafuchiChemical Industry Co., Ltd., Takasago, Hyogo 676, Japan. (Received December 21, 1987; Accepted March 18, 1988) 相似文献
38.
Norio Ogawa Kiminao Mizukawa Kumiko Haba Masato Asanuma Akitane Mori 《Neurochemical research》1992,17(7):687-691
We assayed N-methyl-d-aspartate (NMDA) receptors [3H]3-(2-carboxypiperazin-4-yl)propyl-1-phosphonic acid ([3H]CPP) bindings) and evaluated their distribution in the brain by quantitative autoradiography in young adult and aged rats. In the young adult rats, NMDA receptors were present at relatively high concentrations in the cerebral cortex and hippocampus. In the aged rats, NMDA receptors were decreased in the nealy all areas of the brain, especially in the cerebral cortex and hippocampus. Chronic administration of bifemelane hydrochloride, a drug for sequela of cerebrovascular diseased, at a dose of 15 mg/kg/day for 14 days, markedly attenuated these decrease in NMDA receptors. Since NMDA receptors are considered to be involved in memory and learning processes, our results suggest that bifemelane hydrochloride may be applicable to the treatment of disturbed memory and learning. 相似文献
39.
A novel and efficient method for enzymatic synthesis of high purity maltose using moranoline (1-deoxynojirimycin). 总被引:1,自引:0,他引:1
S Maruo H Yamashita K Miyazaki H Yamamoto Y Kyotani H Ogawa M Kojima Y Ezure 《Bioscience, biotechnology, and biochemistry》1992,56(9):1406-1409
A transglycosylation reaction with moranoline (1-deoxynojirimycin) was done with soluble starch as the glucosyl donor and Bacillus macerans amylase as a cyclodextrin glycosyltransferase [EC 2.4.1.19]. The resultant transglycosylation products with moranoline, obtained by treating the reaction mixture with a strong cation exchange resin, were hydrolyzed by beta-amylase [EC 3.2.1.2] from sweet potatoes. The hydrolysate was treated with a strong cation exchange resin, and high purity maltose was obtained. 相似文献
40.
Acute pulmonary alveolar hypoxia increases lung and plasma endothelin-1 levels in conscious rats. 总被引:13,自引:0,他引:13
G Shirakami K Nakao Y Saito T Magaribuchi M Jougasaki M Mukoyama H Arai K Hosoda S Suga Y Ogawa 《Life sciences》1991,48(10):969-976
To investigate the effect of pulmonary alveolar hypoxia on the synthesis and release of endothelin (ET)-1, ET-1-like immunoreactivity (-LI) levels of the lung and plasma were measured in conscious unrestrained rats under hypoxic conditions. Sixty-min exposure to alveolar hypoxia (10% O2 or 5% O2) increased the ET-1-LI level in the lung. The plasma ET-1-LI level in hypoxic rats also increased significantly. The increase of plasma and lung ET-1-LI levels were parallel to the severity of hypoxia. These results demonstrates that acute pulmonary alveolar hypoxia increases lung and plasma ET-1-LI levels in conscious unrestrained rats, suggesting a possible physiological or pathophysiological significance of ET in alveolar hypoxia. 相似文献