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2001 (1)
1998 (1)
1Author    D. Ámaso, H. Ornero, -. M. Éndez, Marí, Isabel Mínguez-MosqueraRequires cookie*
 Title    Properties of Chlorophyllase from Capsicum annuum L. Fruits  
 Abstract    The in vitro properties of semi-purified chlorophyllase (chlorophyll-chlorophyllido hy­ drolase, EC 3.1.1.14) from Capsicum annuum fruits have been studied. The enzym e showed an optimum of activity at pH 8.5 and 50 °C. Substrate specificity was studied for chlorophyll (Chi) a, Chi b, pheophytin (Phe) a and Phe b, with K m values of 10.70, 4.04, 2.67 and 6.37 ^im respectively. Substrate inhibition was found for Phe b at concentrations higher than 5 ^m. Chlorophyllase action on Chi a' and Chi b' was also studied but no hydrolysis was observed, suggesting that the mechanism of action depends on the configuration at C-132 in the chloro­ phyll molecule, with the enzyme acting only on compounds with R132 stereochemistry. The effect of various metals (Mg2+, Hg2+, Cu2+, Zn2+, Co , Fe2+ and Fe3+) was also investigated, and a general inhibitory effect was found, this being more marked for Hg2+ and Fe2+. Func­ tional groups such as -SH and -S-S-seem ed to participate in the formation o f the enzyme-substrate complex. Chelating ion and the carbonyl group at C3 appeared to be important in substrate recognition by the enzyme. The method for measuring Chlase activity, including HPLC separation of substrate and product, has been optimized. 
  Reference    Z. Naturforsch. 56c, 1015—1021 (2001); received June 27/August 6 2001 
  Published    2001 
  Keywords    Chlorophyll, Chlorophyllase, Capsicum annuum 
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 TEI-XML for    default:Reihe_C/56/ZNC-2001-56c-1015.pdf 
 Identifier    ZNC-2001-56c-1015 
 Volume    56 
2Author    Siegrid Schoch3, M. Onica IhlRequires cookie*
 Title    Substrate Specificity of Chlorophyllase from Different Plants  
 Abstract    The activity of chlorophyllase (chlorophyll-chlorophyllido-hydrolase, EC 3.1.1.14) ex­ tracted from six different species was com pared with enzyme extracted from leaves of Tree of Heaven. The chlorophyllase activity from Swiss chard was similar to the Tree of Heaven enzyme, all the others were less active or inactive. We tested the substrate specificity with bacteriochlorophyll a, chlorophylls a and b. pheophytins a and b and also the synthetic pig­ ments Zn pheophytins a and b and Zn pyropheophytin a. The natural pigments were the best substrates, but the Zn derivatives were also hydrolysed, except Zn pyropheophytin a which was accepted only by the enzyme extracted from the leaves of Tree of Heaven. 
  Reference    Z. Naturforsch. 53c, 21 (1998); received Septem ber 19/October 11 1997 
  Published    1998 
  Keywords    Chlorophyll, Chlorophyllase, Substrates Specificity, Vegetables, Zn pheophytin 
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 TEI-XML for    default:Reihe_C/53/ZNC-1998-53c-0021.pdf 
 Identifier    ZNC-1998-53c-0021 
 Volume    53