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31.
M Ohtsubo M Yoshida S Ohta Y Kagawa M Yohda T Date 《Biochemical and biophysical research communications》1987,146(2):705-710
Using site-directed mutagenesis, Glu-190 or Glu-201 of the beta subunit of the F1-ATPase from the thermophilic bacterium PS3 were replaced with glutamine. It was possible to reconstitute complexes of the mutated beta subunits with alpha and gamma subunits, but the complexes did not have ATPase activity. It is concluded that carboxylic acid side chains of Glu-190 and Glu-201 of the beta subunit are essential for catalytic activity of F1-ATPase. 相似文献
32.
Yasufumi Kaneda Helene Hayes Tsuyoshi Uchida Michihiro C. Yoshida Yoshio Okada 《Chromosoma》1987,95(1):8-12
A human-mouse hybrid segregant HM76Dd40-6 with new characteristics was derived from the hybrid cell line HM76Dd containing human chromosome 19 as the only human chromosome. Three virus sensitivities located on human chromosome 19 (PVS, E11S and RDRC) were lost in HM76Dd40-6, while six other genes (C3, LDLR, EF2, GPI, PEPD and MANB) were retained. Cytogenetic analysis and in situ hybridization using human or mouse repeated sequences as probes showed that the region q13.1-qter of human chromosome 19 had been replaced by a fragment of mouse chromosome. Our results permit further regional assignment for the following five genes on human chromosome 19: GPI in the region cen-q12, MANB in p13.2-q12, E11S and RDRC in q13.1-qter, and EF2 in pter-q12. 相似文献
33.
Analyses of azopigments obtained from the delta fraction of bilirubin from mammalian plasma (mammalian biliprotein). 下载免费PDF全文
Azopigments were obtained from the delta fraction of bilirubin (mammalian biliprotein) in cholestatic sera of men, rats and guinea pigs by diazo reaction with diazotized p-iodoaniline and analysed by t.l.c. Delta bilirubin of men and rats generated both unconjugated and glucuronide-conjugated azodipyrroles, whereas that of guinea pigs, in which the predominant form of conjugated bilirubin in serum was bilirubin monoglucuronide, generated only unconjugated azodipyrrole. We further analysed the azopigments by reversed-phase h.p.l.c. to distinguish their endovinyl and exovinyl isomers. The results indicated (a) that covalent binding of bilirubin to protein occurs exclusively on the conjugated dipyrrolic (either endovinyl or exovinyl) half of the parent conjugated bilirubin, (b) that both bilirubin monoglucuronide and bilirubin diglucuronide generate delta bilirubin, the latter yielding a 'conjugated' form of delta bilirubin that preserves the glucuronic acid moiety on the dipyrrolic half not bound covalently to protein, and (c) that therefore at least four forms of delta bilirubin exist in jaundiced sera of men and rats. 相似文献
34.
Quantitative Analysis of Endogenous Gibberellins in Normal and Dwarf Cultivars of Rice 总被引:7,自引:0,他引:7
Kobayashi Masatomo; Sakurai Akira; Saka Hitoshi; Takahashi Nobutaka 《Plant & cell physiology》1989,30(7):963-969
Endogenous levels of gibberellins in shoots and ears of twodwarf rice (Oryza sativa L.) cultivars, Tan-ginbozu (dx mutant)and Waito-C (dy mutant), were analyzed and compared with thoseof normal rice cultivar, Nihonbare. The endogenous levels of13-hydroxylated gibberellins in Tan-ginbozu were much lowerthan those in Nihonbare. In Waito-C, the levels of GA19 andGA20 in the shoots were higher but that of GA1 was lower thanthe levels of these gibberellins in Nihonbare. These resultssupport the hypothesis that the dy gene controls the 3ß-hydroxylationof GA20 to GA1 while the dx gene controls a much earlier stepin the gibberellin biosynthesis. Our results indicate that GA1is the active gibberellin that regulates the vegetative growthof rice. The endogenous levels of GA4 in the ears of the twodwarf cultivars of rice were higher than the level of GA4 inthe ears of the normal cultivar, Nihonbare suggesting that thebiosynthesis of gibberellin is not blocked in the anthers ofthe dwarf rice. (Received April 27, 1989; Accepted July 12, 1989) 相似文献
35.
M Sobue J Takeuchi T Fukatsu T Nagasaka N Nakashima T Ogura T Katoh K Yoshida 《Stain technology》1989,64(1):43-47
Dermatan sulfate proteoglycan chains were detected in tissue sections treated with chondroitin B-lyase (0.01 units/ml) in 20 mM Tris-HCl (pH 8.0) for 1 hr, followed by staining with antibody 9A2 specific for unsaturated uronic acid coupled to N-acetylgalactosamine-4 sulfate. In contrast, after treatment with chondroitin B-lyase, no positive staining was observed with antibodies 3B3 and 1B5 which react to the unsaturated uronic acid coupled to N-acetylgalactosamine 6-sulfate and unsaturated uronic acid coupled to N-acetylgalactosamine, respectively. The distribution of dermatan sulfate thus revealed was confirmed by comparison with that found by monoclonal antibody 6B6 which reacts with small proteoglycans carrying dermatan sulfate side chains. The localization of positive staining in fibrous connective tissues was almost identical with these two procedures. 相似文献
36.
Isolation and partial characterization of a novel form of low molecular weight kininogen from guinea pig plasma 总被引:1,自引:0,他引:1
Two kinds of low molecular weight kininogen (termed LK1 and LK2) were isolated from pooled plasma of guinea pigs. When polyclonal antisera raised against the individual proteins were used, immunological cross-reactions were observed between LK1 and high molecular weight kininogen (HK), but not either between LK1 and LK2 or between LK2 and HK. After tissue injury, plasma level of LK1 doubled while those of LK2 and HK remained relatively unchanged. 相似文献
37.
Binding sites of HeLa cell nuclear proteins on the upstream region of adenovirus type 5 E1A gene. 总被引:6,自引:3,他引:3 下载免费PDF全文
Twenty one binding sites of HeLa cell nuclear proteins were identified on the upstream region of adenovirus type 5 E1A gene using DNase I footprint assay. The proximal promoter region contained five binding sites that overlapped the cap site, TATA box, TATA-like sequence, CCAAT box, and -100 region relative to the E1A cap site(+1). The -190 region was a potential site for octamer-motif binding proteins, such as NFIII and OBP100. An upstream copy of the E1A enhancer element 1 was the site for a factor (E1A-F) with the binding specificity of XGGAYGT (X = A, C; Y = A, T). E1A-F factor also bound to three other sites, one of which coincided with the distal E1A enhancer element. The distal element also contained a potential site for ATF factor. The adenovirus minimal origin of DNA replication competed for DNA-protein complex formation on the CCAAT and TATA box region and the -190 region, suggesting that these regions interacted with a common or related factor. 相似文献
38.
Rat liver peroxisomal polyamine oxidase activity was determined under various physiological conditions by using the peroxidase method with phenol and 4-aminoantipyrine. N1-Acetylpolyamines such as N1-acetylspermine and N1-acetylspermidine were better substrates than the free polyamines. The polyamine oxidase activity in rat peroxisomes increased significantly when cell proliferation was high. The activity began to appear in fetal liver at the 16th approximately 18th day of pregnancy and peaked in neonatal liver on the first day (approx. 1.7-times higher than in adult liver). In regenerating rat liver, only polyamine oxidase activity among the peroxisomal enzymes tested was increased considerably 12 h after partial hepatectomy (approx. 2.8-fold over the control liver). Finally, the enzyme activity was significantly increased by administration of clofibrate, a peroxisome proliferator, which also causes hepatomegaly. In all cases, the increase in polyamine oxidase activity was not more than 3-fold. Since the level of polyamine oxidase activity in the normal liver is more than adequate in relation to the level of the substrates, the slight but significant increase under conditions of cell proliferation may have a role in modulating levels of polyamines in the proliferating liver tissue. 相似文献
39.
Physiological state control of fermentation processes 总被引:1,自引:0,他引:1
In this article a novel approach to the control of fermentation processes is introduced. A "physiological state control approach" has been developed using the concept of representing fermentation processes through the current physiological state of the cell culture. No conventional mathematical model is required for the synthesis of such a control system.The main idea is based on the fact that during batch, feed-batch, or even continuous cultivation the physiological characteristics of the cell population, jointly expressed by the term "physiological state", are not constant but rather variable, which is reflected in expected or unexpected changes in the behavior of the control plant, and which requires flexible alteration of the current control strategy. The proposed approach involves decomposition of the physiological state space into several subspaces called "physiological situations." In every physiological situation the cell population expresses stable characteristics, and therefore an invariant control strategy can be effectively applied. The on-line functions of the physiological state control system consist of the calculation of physiological state variables, determination of the current physiological situation as an element of a previously defined set of known physiological situations, switching of the relevant control strategy, and calculation of the control action. Attention is focused on the synthesis of the novel and nonstandard part of the control system - the algorithm for online recognition of the current physiological state. To this end an effective approach, based on artificial intelligence methods, particularly fuzzy sets theory and pattern recognition theory, was developed. Its practical realization is demonstrated using data from a continuous fermentation process for single cell protein production. 相似文献
40.
The stability of immobilized maltotetraose (G(4))-forming amylase (1,4-alpha-D-glucan maltoteraohydrolase, EC 3.2.1.60) from Pseudomonas stutzeri was investigated in both batch and continous processes. The inactivation process of the immobilized enzyme seemed to obey first-order kinetics, and the immobilized enzyme became more stable when coexisting with 20-30 wt % substrate and calcium ions. From intensive studies on the operational stability in the continuous process, the apparent half-life of G(4) productivity in a constant-flow system was mainly affected by the reaction temperature, substrate concentration, and initial immobilized enzyme activity. A new factor, immobilized enzyme stability factor f(s), was proposed to evaluate the half-life of the immobilized enzyme system. 相似文献