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51.
Manuel Grez Hartmut Land Klaus Giesecke Günther Schütz Alexander Jung Albrecht E. Sippel 《Cell》1981,25(3):743-752
We have determined the DNA sequence of a 770 by Pst I fragment containing 450 nucleotides of the 5′ flanking region of the chicken lysozyme gene. S1-nuclease mapping was performed to localize the 5′ end of nuclear RNA containing lysozyme-specific sequences and of the mRNA. We present evidence that the 5′ noncoding region of the chicken lysozyme mRNA is heterogeneous in length. The 5′ termini of the different mRNAs map 29, 31 and 53 nucleotides upstream from their common initiation codon. The 5′ ends of lysozyme-specific nuclear RNAs map at positions similar to that of the mRNA. AT-rich regions and sequences similar to the E. coli RNA polymerase recognition sequence are found around 30 and 70 nucleotides upstream from each of these 5′ termini. The AT-rich regions differ, however, from the canonical Goldberg-Hogness box in that they do not contain the extremely conserved TATA sequence motif. Sequence comparison at the 5′ end of the lysozyme, conalbumin and ovalbumin genes reveals only one region of partial homology, 140 nucleotides upstream from the mRNA start sites. 相似文献
52.
From the mycelia of Aspergillus cristatus the following anthraquionic pigments were isolated: catenarin, emodin, erythroglaucin, rubrocristin, physcion, physcion-9-anthrone, questin, viocristin, and isoviocristin. The latter two do not belong to the 9, 10-anthraquinone series but to the 1,4-anthraquinones, and so far they have not been reported among naturally occurring quinones.Emodin, catenarin, viocristin, and isoviocristin snowed antibacterial activity with minimal inhibitory concentrations ranging from 1–10 g/ml. In Bacillus brevis catenarin and emodin inhibited the incorporation of uracil and leucine preferentially. At higher concentrations the incorporation of thymidine into the trichloroacetic acid-precipitable fraction of cells was also affected. In the presence of viocristin or isoviocristin all three macromolecular syntheses came to a halt. Rubrocristin, erythroglaucin, and physcion showed no significant inhibitory effects.In Ehrlich ascites carcinoma cells catenarin, emodin, and viocristin inhibited the incorporation of uridine and thymidine. The incorporation of leucine was hardly affected.In vitro, inhibition of DNA-dependent RNA polymerase from Escherichia coli by catenarin and to a lesser extent by emodin was observed, whereas rubrocristin (catenarin-8-methyl ether), physcion, and erythroglaucin were not active.Abbreviations MIC
minimal inhibitory concentration
- TCA
trichloroacetic acid
- ECA
Ehrlich ascites carcinoma
Metabolic Products of Microorganisms. 191. W. Keller-Schierlein und B. Joos; Über das 4-Oxohomotyrosin, ein Abbauprodukt des Echinocandins. Helv. Chim. Acta (in press) 相似文献
53.
Mitochondria have been prepared from the flight muscles of mature blowflies (Sarcophaga bullata). Phosphate transport by these mitochondria, determined by rates of passive swelling in ammonium phosphate, is sensitive to inhibition by N-ethylmaleimide. 20 nmol of N-ethylmaleimide/nmol cytochrome a inhibit the swelling by 90%. When the mitochondria are inhibited by , then solubilized in dodecyl sulfate/mercaptoethanol at 100°C and then electrophoresed on dodecyl sulfate-polyacrylamide gels, many labeled protein bands can be detected, including a large labeled peak that has the same mobility as the tracking dye, bromophenol blue. Sonic submitochondrial particles that are prepared from the mitochondria, solubilized, and electrophoresed on dodecyl sulfatepolyacrylamide gels, possess only seven major labeled protein bands with no radioactive peak at the tracking dye. These labeled proteins have molecular weights of 71, 68, 64, 45, 32, 30, and approx. 10 · 103. The nmol bound to each of these proteins per nmol cytochrome a are 0.15, 0.19, 0.35, 0.45, 0.87, 0.10, and 0.17, respectively, when the mitochondria are inhibited with 21.5 mol cytochrome a at 10 μM cytochrome a. Coty and Pedersen ((1975) J. Biol. Chem. 250, 3515–3521) sensitized rat liver mitochondria to and identified five labeled proteins. Only the labeled 32 · 103 dalton and the 45 · 103 dalton proteins are common to both systems 相似文献
54.
With the data of the osteological paleontology and these of the ichnology, the authors attempt to restore the biotopes where lived the trackmakers, biotopes which have favoured in the Triassic the evolution and the expansion of the Archosaurs, the specialized Reptiles in the easy and rapid locomotion. They pointed out that the chirotheroid footprints cannot be attributed at all events to the Pseudosuchians and they come to the conclusion that Dinosaurs and Pseudosuchians, as separated groups, are appeared as early as the lower Triassic. 相似文献
55.
Summary The occurrence of heterotrophic nitrification in nitrogen-starved cells of Ankistrodesmus braunii was confirmed. The levels of nitrate and nitrite were measured over a period of four weeks. The validity of quantitative determinations in the presence of highly active nitrate and nitrite reductases is discussed. Whereas free hydroxylamine as an intermediate could not be detected, increased hydroxylamine oxidase activity was found in nitrogen-starved cultures. Nitrite reductase and hydroxylamine oxidase can be assigned to particles by sucrose density gradient centrifugation. The possible involvement of microbodies, which were found to be present in Ankistrodesmus, in metabolic processes during nitrogen starvation is discussed.Abbreviations NR
nitrate reductase
- NiR
nitrite reductase
- NNEDA
N-(1-naphthyl)ethylenediaminedihydrochloride
- DCPIP
2,6-dichlorophenolindophenol
- EDTA
ethylenediaminetetraacetic acid
- TCA
trichloroacetic acid
- DAB
3,3-diaminobenzidine
- AT
3-amino-1H-1,2,4-triazole
- AMP
2-amino-2-methyl-1,3-propanediol 相似文献
56.
The fermentative metabolism of Rhodospirillum rubrum (strain Ha, F1, S1) was studied after transfering the cells from aerobic to anaerobic dark culture conditions. Pyruvate was metabolized mainly to acetate and formate, and to a lesser extent to CO2 and propionate, by all strains. Therefore, pyruvate formate lyase would appear to be the characteristic key enzyme of the dark anaerobic fermentation metabolism in R. rubrum. Strain F1 and S1 metabolized the formate further to H2 and CO2. It is concluded that this cleavage was catalysed by a formate hydrogen lyase system. Strain Ha was unable to metabolize formate. The cleavage of formate and the synthesis of poly--hydroxy-butyric acid were increased by a low pH value (6.5). Fermentation equations and schemes of the pyruvate metabolism are discussed. 相似文献
57.
Summary The preparation of a mannan-iron complex is described. The mannan-iron complex can be used for electron microscopic demonstration of membrane bound Concanavalin A or Lens culinaris lectin because the high reactivity of these lectins toward the mannan. 相似文献
58.
59.
Wheat grains were embedded with or without fixation in Technovit 7100 or in paraffin. This enabled us to produce 4 μm sections for imnwnofluorescent staining to see whether serum of patients with baker's asthma contained IgG antibodies against wheat grains. Embedding without fixation in Technovit 7100 appeared to be suitable for unmunofluorescent staining and gave superior results to protocols requiring fixation. 相似文献
60.
Dominik Karch Keun-Sun Kim Katarzyna Wochner Heike Philippi Joachim Pietz Hartmut Dickhaus 《Journal of biomechanics》2010,43(9):1844-1848
In motion capture applications using electromagnetic tracking systems the process of anatomical calibration associates the technical frames of sensors attached to the skin with the human anatomy. Joint centers and axes are determined relative to these frames. A change of orientation of the sensor relative to the skin renders this calibration faulty. This sensitivity regarding sensor displacement can turn out to be a serious problem with movement recordings of several minutes duration. We propose the “dislocation distance” as a novel method to quantify sensor displacement and to detect gradual and sudden changes of sensor orientation. Furthermore a method to define a so called fixed technical frame is proposed as a robust reference frame which can adapt to a new sensor orientation on the skin. The proposed methods are applied to quantify the effects of sensor displacement of 120 upper and lower limb movement recordings of newborns revealing the need for a method to compensate for sensor displacement. The reliability of the fixed technical frame is quantified and it is shown that trend and dispersion of the dislocation distance can be significantly reduced. A working example illustrates the consequences of sensor displacement on derived angle time series and how they are avoided using the fixed technical frame. 相似文献