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'Suspension Cultures' in keywords Facet   Publication Year 1988  [X]
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1Author    Yüko Yamashita, Hiroshi AshiharaRequires cookie*
 Title    Characterization of Hexokinase and Fructokinase from Suspension-Cultured Catharanthus roseus Cells  
 Abstract    Two different hexose-phosphorylating enzymes, hexokinase and fructokinase, were partially purified from suspension-cultured Catharanthus roseus cells. One of the enzymes, hexokinase, catalyzed the phosphorylation of both glucose and fructose. The K m values for glucose and fructose were 0.06 mM and 0.23 mM, respectively. The V max of the enzyme with fructose was approximately three times higher than with glucose. This enzyme was specific in its requirement for ATP and its K m value for ATP was 52 (ÍM. The optimum pH was 8.0 and Mg :+ or Mn :+ was required for the activity. The activity was inhibited by considerably higher concentrations of ADP (i.e., 4 mM ADP was required for 50% inhibition). The second enzyme, fructokinase, was specific for fructose, and no activity was detected with glucose as substrate. This enzyme used UTP or CTP as phosphate donor. The K m values of this enzyme for fructose and UTP were 0.13 mM and 0.15 mM, respectively. The pH optimum was 7.2, and Mg 2+ or Mn 2+ was required for the activity. These divalent cations could be partially replaced by Ca 2+ . The activity was inhibited non-competitively by ADP and AMP. 90% inhibition of the activity by 0.5 mM ADP was observed in the presence of 2 mM UTP and 5 mM MgCl 2 . Fructose-2,6-bisphosphate, glucose-1,6-bisphos-phate, glucose-6-phosphate, and fructose-6-phosphate had little or no effect on the activity of both the hexokinase and the fructokinase. Based on these results, a discussion is presented of the role of hexokinase and fructokinase and their involvement in the regulation of the metabolism of sugars in Catharanthus cells. 
  Reference    Z. Naturforsch. 43c, 827—834 (1988); received June 28 1988 
  Published    1988 
  Keywords    Catharanthus roseus, Suspension Culture, Fructokinase, Glycolysis, Hexokinase 
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 TEI-XML for    default:Reihe_C/43/ZNC-1988-43c-0827.pdf 
 Identifier    ZNC-1988-43c-0827 
 Volume    43 
2Author    Koshi Saito, Etuko Daimon, Kazuhito Kusaka, Sachio Wakayama, Yoshihiro SekinoRequires cookie*
 Title    Accumulation of a Novel Red Pigment in Cell Suspension Cultures of Floral Meristem Tissues from Carthamus tinctorius L  
 Abstract    A cell strain originally derived from floral meristem tissues of Carthamus tinctorius (dyer's saffron) produced substantial amounts of a novel red pigment under controlled culture conditions. The pigment isolated from alcoholic extracts of C. tinctorius cultures was compared with authentic carthamin, anthocyanins, betain, and carotenoids. It differed markedly from carthamin and showed none of the characteristic properties of the glycoside or chloride forms of authentic delphinidin, cyanidin, and pelargonidin. Analytic data indicated that this pigment also differs from betanin and from a-and ß-carotene. The name "Kurenamin" was tentatively given to this newly isolated red pigment. Effect of the culture media, micro-elements, macro-elements, and putative substrates on the kurenamin production were investigated during cell suspension culture. 
  Reference    Z. Naturforsch. 43c, 862—870 (1988); received September 2 1988 
  Published    1988 
  Keywords    Carthamus tinctorius, Pigment Accumulation, Suspension Culture 
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 TEI-XML for    default:Reihe_C/43/ZNC-1988-43c-0862.pdf 
 Identifier    ZNC-1988-43c-0862 
 Volume    43