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51.
Osamu Gotoh Jun-Ichi Hayashi Hiromichi Yonekawa Yusaku Tagashira 《Journal of molecular evolution》1979,14(4):301-310
Summary We have developed a theory to estimate the degree of sequence divergence between related DNAs from the comparison of restriction endonuclease recognition sites. Two major improvements have been made upon a similar method reported by Upholt (1977). First, the most probable value is calculated by the collective use of all available data. This reduces intrinsic statistical error and extends the analyzable range of sequence divergence. Second, all variables are redefined so that they have strict mathematical implications. This corrects a serious error arising from the misinterpretation of the meaning of the fraction of conserved cleavage sites. With this refined method, sequence divergence between rat and mouse mitochondrial DNAs (mtDNAs) was calculated to be about 25% substitutions/nucleotide, which is in good agreement with the DNA-DNA hybridization data obtained by Jakovcic et al. (1975). It was also estimated that the three types of rat mtDNAs differ from one another by 0.3 ~1% of total base pairs. These values are 2 ~5 times smaller than those obtained with the conventional method. 相似文献
52.
Kiyomi Wada Akeo Kadota Hiromichi Tanihira Yoshihiro Suzuki 《Journal of plant research》1981,94(3):239-247
Suspension of protoplasts (ca. 13–25 μm in diameter) that were isolated from the mesophyll of the cotyledons ofPharbitis nil, strain Violet, contained many large spherical or spheroidal bodies (ca. 100 μm in diameter). Microscopic observation of these bodies and some anatomic studies of the cotyledons during embryogenesis and after germination showed that these bodies are giant cells containing many oil drops stainable with Sudan dyes. Such giant cells were found in four otherPharbitis nil strains, Nepal, Tendan, Africa and Tokyo-kokei, and in six other Convolvulacean plants,Ipomoea batatas, cv. Koukei-14,Calystegia japonica, Calystegia hederacea, Calonyction aculeatum, Quamoclit pennata andCuscuta japonica. 相似文献
53.
Hiromichi Kayano Isao Karube Tadashi Matsunaga Shuichi Suzuki Ooki Nakayama 《Applied microbiology and biotechnology》1981,12(1):1-5
Summary A blue-green algae, Anabaena N-7363, was immobilized in 2% agar gel. The hydrogen productivity of the immobilized algae was three times higher than that of free algae. The maximum hydrogen production rate by the immobilized blue-green algae was 0.52 moles h–1 g–1 (of wet gel) in the medium without nitrogen sources under illumination (10,000 lux). The oxygen evolved was then removed by a reactor containing aerobic bacteria. A photo-current of 15–20 mA was continuously produced for 7 days by the photochemical fuel cell system consisting of the immobilized Anabaena reactor, the oxygen-removing reactor and the hydrogen-oxygen fuel cell. The conversion ratio of hydrogen to current was from 80% to 100%. 相似文献
54.
Infrared analysis of pea stem cell walls and oriented structure of matrix polysaccharides in them 总被引:4,自引:0,他引:4
Infrared absorption spectra of film specimens of the epidermaland parenchyma cell walls of the third internode of pea stem,before and after protease treatment and after treatment forremoval of lipid materials, pectic substances and hemicellulose,were recorded, and characteristic bands in the spectrum of thewall were assigned. Polarization spectrum measurements of thewall provided evidence indicating that the non-cellulosic polysaccharidematrix as well as cellulose microfibrils has an oriented structurein the wall which changes during extension growth as well asupon mechanical extension of the walls. (Received March 9, 1978; ) 相似文献
55.
The increase in the dichroism of the ester-C=O and COObands in response to mechanical extension in oat coleoptilecell walls was much enhanced by IAA pretreatment while the decreasein that of the C-O-C band was not enhanced or even suppressed.The results indicate the importance of the ultrastructure ofnon-cellulosic polysaccharides in controlling auxin-inducedcell elongation.
1 Present adress: Department of Agricultural Chemistry, KyotoPrefectural University, Shimogamo, Kyoto 606, Japan. (Received May 16, 1978; ) 相似文献
56.
Tritiated 3-O-methyl-d-glucose has many useful attributes as a model substance for studies of the transport of glucose across cell membranes. However, preparations of high specific radioactivity can decompose within a few months, producing radioactive impurities that can cause a several-fold increase in the apparent rate of sugar transport. In our investigation radioactive contaminants entered frog skeletal muscle cells by free diffusion rather than by facilitated transport. Much of the contaminating radioactive material could be removed by evaporating the solvent and redissolving the sugar. Tritiated sugar samples that had a specific activity below 0.1 Ci/mmol remained stable and suitable for transport measurements after several years of storage at -20°C. In order to evaluate the suitability of a given tritiated preparation of sugar for transport measurements, it is recommended that its behavior be compared with that of a stable reference standard of low specific activity. 相似文献
57.
G Maglione O Matsushita J B Russell D B Wilson 《Applied and environmental microbiology》1992,58(11):3593-3597
A pUC19-derived plasmid was constructed that coded for a hybrid cellulase with the Thermomonospora fusca E2 cellulose-binding domain at its C terminus joined to the Prevotella ruminicola 40.5-kDa carboxymethyl cellulase (CMCase). The hybrid enzyme was purified and characterized enzymatically. It bound tightly to cellulose, and its specific activities on carboxymethyl cellulose, amorphous cellulose, and ball-milled cellulose were 1.5, 10, and 8 times that of the 40.5-kDa CMCase, respectively. Furthermore, the modified enzyme gave synergism with an exocellulase in the degradation of filter paper, while the 40.5-kDa CMCase did not. 相似文献
58.
The effect of extraction of weakly bound Ca2+ by low-pH treatment on the O2-evolving apparatus was studied by use of low-temperature electron paramagnetic resonance (EPR) and X-ray absorption spectroscopy. In low-pH-treated PSII membranes, an S2 EPR multiline signal with modified line shape was induced by illumination at 0 degrees C, but its signal amplitude decreased upon lowering the excitation temperature with concomitant oxidation of cytochrome (cyt) b-559 in place of Mn. The half-inhibition temperature for formation of the modified multiline signal was found at -33 degrees C, which was much higher than that for formation of the normal S2 state in untreated control membranes. Signal IIf was normally induced down to -30 degrees C, but its dependence on excitation temperature was different from that for modified S2. This was interpreted as indicating that the low-temperature blockage of modified S2 formation is due to the incapability of electron abstraction from the Mn cluster. The Mn K-edge of X-ray absorption near-edge structure (XANES) spectrum shifted to lower energy by 0.8 eV after low-pH treatment, but the shift was reversed by addition of Ca2+. Upon illumination at 0 degrees C of treated membranes, the K-edge energy was up-shifted by 0.8 eV, but was not upon illumination at 210 K. These results were interpreted as indicating that extraction of weakly bound Ca2+ by low-pH treatment gives rise to structural and functional modulations of the Mn cluster. 相似文献
59.
Kazunori Maruyama Kouji Nagata Minoru Tanaka Hiromichi Nagasawa Akira Isogai Hironori Ishizaki Akinori Suzuki 《The protein journal》1992,11(1):1-12
We report the synthesis of bombyxin-IV, a disulfide-linked, heterodimeric, insulin superfamily peptide from the silkworm,Bombyx mori. The two chains (A- and B-chains) were synthesized separately by the solid-phase method using fluoren-9-ylmethoxycarbonyl (Fmoc) group as a protecting group for α-amino group. Three disulfide bonds were bridged step by step (A6–A11, A20–B22, and A7–B10) in a good yield. Synthetic bombyxin-IV was identical with natural one with regard to the retention time on a reversed-phase column and the molecular weight measured by mass spectrometry. Circular dichroism (CD) spectrum of the synthetic bombyxin-IV was very similar to that of the natural one. The specific activity of synthetic bombyxin-IV is equal to that of natural one (0.1 ng/Samia unit). These results suggest that the synthetic bombyxin-IV has the tertiary structure identical with the natural peptide. Our method developed for synthesis of bombyxin-IV would be generally applicable to the synthesis of insulin-like heterodimeric peptides. 相似文献
60.
M Nashina E Hori K Matsushita M Takahashi K Kato A Ohsaka 《International journal for parasitology》1990,20(1):131-132
In an attempt to study nitrogen metabolism in a parasite, we applied 15N-nuclear magnetic resonance (NMR) technology with a stable isotope, a 15N-labeled compound, for the study of the transamination system in A. cantonensis eggs, and demonstrated that 15N-aspartic acid can serve as an amino group donor for both the 2-oxoglutaric-glutamic acid and the pyruvic acid-alanine transamination systems in the eggs. 相似文献