跳到主要內容

臺灣博碩士論文加值系統

(44.192.20.240) 您好!臺灣時間:2024/02/24 02:14
字體大小: 字級放大   字級縮小   預設字形  
回查詢結果 :::

詳目顯示

我願授權國圖
: 
twitterline
研究生:周正平
研究生(外文):Chou, Chen-Ping
論文名稱:麩胱甘�B轉移�@(GST)對四氯異苯�顒漸N謝
論文名稱(外文):Metabolism of Chlorothalonil by Glutathione S-Transferase
指導教授:蔣啟玲蔣啟玲引用關係
指導教授(外文):Chii-Ling Jeang
學位類別:碩士
校院名稱:國立中興大學
系所名稱:食品科學系
學門:農業科學學門
學類:食品科學類
論文種類:學術論文
論文出版年:1998
畢業學年度:86
語文別:中文
論文頁數:62
中文關鍵詞:麩胱甘轉移四氯異苯
外文關鍵詞:Glutathione S-TransferaseChlorothalonil
相關次數:
  • 被引用被引用:1
  • 點閱點閱:114
  • 評分評分:
  • 下載下載:0
  • 收藏至我的研究室書目清單書目收藏:0
中文摘要殺菌劑四氯異苯為目前本省推薦使用於作物病害防治上常用之
農藥。由於四氯異苯在生物體內受 GST 的催化與 GSH 形成GSH-共軛衍
生物而啟始一連串的代謝反應,而最後形成的硫代物質會抑制粒腺體的呼
吸作用,導致細胞的死亡,故引起學者廣泛的研究。本實驗之目的即在建
立以化學法及酵素法合成代謝產物─四氯異苯-GSH衍生物,並探討分離
自人體內非病原性的大腸桿菌中之 GST ,對四氯異苯之作用。發現酵
素法可直接得到代謝產物,化學合成則因副反應同時會產生其它的不純物
,將目標物以 HPLC 淨化後,再經 LC/MS 鑑定產物之分子量,而得到與
期望之衍生物相吻合的質譜圖,證明代謝衍生物可經由化學及酵素法合成
。以超高速離心,硫酸銨沈澱區分及親和管柱分離等步驟分離來自大腸桿
菌的GST,回收率 ( 產量 ) 為12.8 %,以40 μl ( 1.0 μg/ml ) 的GST
催化四氯異苯 (39μM,約10 ppm ) 及1.0 mM GSH反應24小時後,所得
之代謝產物量較控制組 ( GST去活化 ) 為高,表示非病原性大腸桿菌中
的 GST 會代謝四氯異苯形成GSH-衍生物。
AbstractChlorothalonil is an important broad spectrum contact
fungicide that has been widely used to control diseases of
plants for about 25 years. One toxicological issue that
continues to cause regulatory concern by EPA. U.S.A. is that
chronic dietary administration of chlorothaloni to rodents
induces a series of nonneoplastic histopathological changes in
the epithelial cells of the proximal tubule of the kidney and
the squamous epithelium of the forestomach. The mechanisms of
the histopathlogical changes are initiated by the GSTs''
enzymatic reaction to produce the GSH-conjugated compounds,
which are metabolized to cytotoxic thiols by cysteine conjugated
β-lyase pathway. Our study is to identify the glutathionyl
conjugates of chlorothalonil 1-3 compounds by using LC/MS and to
isolate the GSTs from the non-pathogenic Escherichia coli for
assaying the GSH-conjugated compounds formed by this enzyme. The
results show that the high purity of chlorothalonil-GSH
conjugates 1-3 could be obtained by enzymatical methods. And
the molecular weights of the glutathionyl conjugates of
chlorothalonil 1-3 are agreeable with LC/MS determined, after
clean-up by HPLC. E.coli E1 was used as sources of GST. The
bacterial cells were grown at 37℃ in 1.5 liters of LB broth,
and were harvested and washed twice with buffer . After the
cells were broken by ultra sonication, the cell homogenate was
centrifuged at 100,000×g for 1h. The supernatant was used as
crude enzyme extract.The enzyme was purified stepwisely by
ammonium sulfate fractionation and GSH-affinity chromatography.
The yield as measured by enzymatic activity was 12.8 %. Forty
μl of partially purified GST ( 1.0 μg/ml ) was reacted with
1.0 mM GSH and 39 μM chlorothalonil for 24h. The amount of
GSH-conjugates of chlorothalonil produced was higher than the
control ( 1.0 mM GSH and 39 μM chlorothalonil only ).
QRCODE
 
 
 
 
 
                                                                                                                                                                                                                                                                                                                                                                                                               
第一頁 上一頁 下一頁 最後一頁 top