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81.
19F-n.m.r. spectra were measured to investigate the effects of Ca2+ and Zn2+ on the interaction of trifluoperazine (TFP) with three S100 proteins. It was found that TFP binds to S100a and S100ao proteins irrespective of the presence of Ca2+ and Zn2+, while in the presence of Ca2+ the apparent affinity of TFP to the proteins was greater than that in its absence or in the presence of Zn2+. In contrast, the binding affinity of TRP to S100b protein in the presence and absence of metal ions was lower than to S100a and S100ao proteins. These results suggested that TFP binds to each S100 protein in two ways: one is Ca2(+)- or Zn2(+)-dependent specific manner and another is Ca2(+)- or Zn2(+)-independent non-specific manner.  相似文献   
82.
83.
redD and actII-ORF4, regulatory genes required for synthesis of the antibiotics undecylprodigiosin and actinorhodin by Streptomyces coelicolor A3(2), were transcribed in vitro by an RNA polymerase holoenzyme containing sigma hrdD. Disruption of hrdD had no effect on antibiotic production, indicating that redD and actII-ORF4 are transcribed in vivo by at least one other RNA polymerase holoenzyme. These data provide the first experimental evidence that HrdD can function as a sigma factor.  相似文献   
84.
Persistent infections with mumps virus were established in several human lymphoid cells of T-cell origin (Molt-4, TALL-1, and CCRF-CEM) and human monocyte cells (U937 and THP-1). 2′,5′-Oligoadenylate synthetase (2–5AS) activity was demonstrated to be only slightly induced by interferon (IFN) or TPA (12-O-tetradecanoyl-phorbol-13-acetate) treatment in these cells. Treatment of the persistently infected cells with IFN or TPA did not stimulate an increase in the amount of synthetase mRNA. Induction of cell differentiation and augmentation of IFN production by TPA were demonstrated in U937 cells persistently infected with mumps virus (U937-MP). Similar results for IFN production were obtained from differentiated U937 cells. It is suggested that cell differentiation of U937 cells might be associated with the development of IFN inducibility.  相似文献   
85.
86.
The polypeptide encoded by the partial fragment of cDNA of phenylalanine ammonia-lyase (PAL; EC 4.3.1.5), PALcDNAl (Osakabe et al., 1995, Plant Sci. 105: 217–226), isolated from Populus kitakamiensis (P. sieboldii x P. grandidentata), was expressed in Escherichia coli cells. The polypeptide was purified and an antiserum raised against it. The antiserum recognized a protein of 77 kDa on nitrocellulose blots after sodium dodecyl sulfate-poly-acrylamide gel electrophoresis of total protein and the partially purified PAL protein from P. kitakamiensis. Moreover,the antiserum recognized a protein on the blot after non-denaturing polyacrylamide gel electrophoresis of P. kitakamiensis proteins and this protein had PAL activity. Furthermore, the antibody inhibited PAL activity of extracts from stem tissues. These results showed that the antiserum against the partial PAL peptide recognized only the PAL subunits in extracts of P. kitakamiensis. Immunolocalization studies of P. kitakamiensis tissues revealed that the PAL protein was specifically localized in the xylem and the phloem fibers and no immunogold signal was found in the epidermis, the cortex, the pith, or the cambium of either stems or leaves.Abbreviations IgG immunoglobulin G - IPTG isopropylthio--d-galactoside - PAL phenylalanine ammonia-lyase The authors thank Dr. Kunio Hata of Nippon Paper Industries Co., Ltd. (Japan) for supplying P. kitakamiensis. This work was supported in part by a grant-in-aid for Scientific Research from the Ministry of Education, Science and Culture of Japan (No. 07406008).  相似文献   
87.
A. Kikuchi  Y. Edashige  T. Ishii  T. Fujii  S. Satoh 《Planta》1996,198(4):634-639
Carrot (Daucus carota L.) embryogenic callus (EC) loses its embryogenic competence and becomes nonembryogenic callus (NC) during long-term culture. With the loss of embryogenic competence, the cell clusters become smaller and the extent of intercellular attachments is reduced. Pectic fractions prepared from EC and NC were separated into two subfractions by gel filtration. A difference in sugar composition between EC and NC was found only in the high-molecular-mass (ca. 1300 kDa) subfraction, and the ratio of the amount of arabinose to that of galactose (Ara/Gal) was strongly and positively correlated with the size of cell clusters in several different cultures. From the results of sugar-composition and methylation analyses, and the results of treatment with exo-arabinanase, models of the neutral sugar chains of pectins from EC and NC are proposed. Both neutral sugar chains are composed of three regions. The basal region is composed of linearly linked arabinan 5-Araf> moieties in both types of callus. The middle galactan region is composed of 6-linked galactose, some of which branches at the 3 and 4 positions, and this region is larger and more frequently branched in NC than in EC. Finally, the terminal arabinan region is composed of 5-linked arabinose, branched at the 3 position, and the size of the terminal arabinan is larger in EC than in NC. The significance of the neutral sugar chains of pectins in the interaction of cell wall components and intercellular attachment is discussed.Abbreviations Ara/Gal ratio (w/w) of the amount of arabinose to that of galactose - EC embryogenic callus - NC non-embryogenic callus - T-Araf terminal arabinose The authors are grateful to Dr. Naoto Shibuya of the National Institute of Agrobiological Resources for his gift of exo-arabinanase.  相似文献   
88.
89.
Based on the hypothesis that the relation between sweating rate and body temperature should be different during exercise and rest after exercise, we compared the sweating response during exercise and recovery at a similar body temperature. Healthy male subjects performed submaximal exercise (Experiment 1) and maximal exercise (Experiment 2) in a room at 27° C and 35% relative humidity. During exercise and recovery of 20 min after exercise, esophageal temperature (Tes), mean skin temperature, mean body temperature ( ), chest sweating rate ( ), and the frequency of sweat expulsion (F SW) were measured. In both experiments, andF SW were clearly higher during exercise than recovery at a similar body temperature (Tes, ). was similar during exercise and recovery, or a little less during the former, at a similarF SW. It is concluded that the sweating rate during exercise is greater than that during recovery at the same body temperature, due to greater central sudomotor activity during exercise. The difference between the two values is thought to be related to non-thermal factors and the rate of change in mean skin temperature.  相似文献   
90.
Journal of Plant Research - A group of temperate grassland plant species termed the “Mansen elements” occurs in Japan and is widely distributed in the grasslands of continental East...  相似文献   
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