English  |  正體中文  |  简体中文  |  Items with full text/Total items : 16702/18989 (88%)
Visitors : 5525356      Online Users : 63
RC Version 7.0 © Powered By DSPACE, MIT. Enhanced by NTU Library IR team.
Scope Tips:
  • please add "double quotation mark" for query phrases to get precise results
  • please goto advance search for comprehansive author search
  • Adv. Search
    HomeLoginUploadHelpAboutAdminister Goto mobile version
    Please use this identifier to cite or link to this item: http://ir.cnu.edu.tw/handle/310902800/28429


    標題: Purification And Characterization of Sucrose Synthetase From Banana Fruits
    作者: DONG-BOR TEN
    JONG-CHING SU
    貢獻者: 私立嘉南藥學專科學校
    日期: 1975
    上傳時間: 2014-12-26 11:49:06 (UTC+8)
    摘要: In this study, lyophilized banana fruits were used as the source of sucrose synthetase (UDP-glucose:D-fructose 2-glucosyltransferase, 2.4.1.13).Extraction by grinding with a buffer containing caffeien and 2-mercaptoethanol yielded a crude extract which could be further purified by fractionation with?ammonium sulfate and adsorption on calcium phosphate gel. It was found that the interfering factors encountered previously such as tannins, pectic substances and polyphenoloxidase could be eliminated by these procedures, and the enzyme with a relatively high activity was obtained. Furthermore, an?activity of sucrose phosphate synthetase (UDP-glucose:D-fructose 6-phosphate 2-glucosyltransferase, 2.4.1.14), which had not yet been demonstrated?in banana fruits before,was alos detected in the crude extract. Partially purified sucrose synthetase from banana fruits was more stable at 0- 4° and at pH values between 6. 0-9.0. The optimum pH of this enzyme for?catalyzing the reaction in the direction of sucrose cleavage was about 6.5.This enzyme showed relatively broad specificities to di- and trisaccharides and to nucleoside diphosphates. No activator for this enzyme was found and heavy?metal ions such as Cu++, Hg++ and Ag+ completely inhibited the enzyme action at a concentration of 4x10-3M. Thiol group reagents including p-mercurcuriben-zoate (PCMB), N-ethylmaleimide and iodoacetic acid showed no or little in-hibitory effect at concentrations normally capable of inhibiting an SH enzyme.The molecular weight determined by the gel filtration technique was about 420,000. It was interesting to compare this data to the sedimentation coefficient(S209w)6.9, which was estimated by a sucrose density gradient ultracentrifugation technique. The Km value of this enzyme for sucrose at standard assay?condition was 6.99x10-2M and the S0.5 value for UDP 0.83x10-4M.The Hill coefficients (n values) estimated from Hill plots were 1.0 and 1.53 for sucrose and UDP respectively, indicating that the enzyme could be an allosteric protein but its binding behavior toward sucrose was different form other known sucrose synthetases.
    關聯: 嘉南學報, n.1 pp.74-89 轉載
    Appears in Collections:[藥學系(所)] 期刊論文
    [嘉南學報] 1期 (1975)

    Files in This Item:

    There are no files associated with this item.



    All items in CNU IR are protected by copyright, with all rights reserved.


    DSpace Software Copyright © 2002-2004  MIT &  Hewlett-Packard  /   Enhanced by   NTU Library IR team Copyright ©   - Feedback