不同受質及抑制劑在不同酸鹼環境中影響酚亞硫酸基轉移酵素的催化效應之結果

Abstract

不同受質及抑制劑在不同酸鹼環境中影響酚亞硫酸基轉移酵素的催化效應之結果 學生: 王郁琛 指導老師: 楊裕雄 博士 國立交通大學生物科技學系碩士班 摘要 生理上的硫酸化在生物體中扮演著相當重要的角色，尤其是對一些外來物質的排除更是重要；和硫酸基的結合會增加親油性物質的水溶性，如此將有利於這些親油性物質的排除。在生理上，有許多重要的新陳代謝中間產物會產生硫酸化或去硫酸化的現象，而這種加入或去除的動作則會影響這些新陳代謝中間產物在生理上的角色扮演，進而達成對代謝途徑的調控。前人的研究顯示：酚亞硫酸基轉移酵素不僅會催化酚類的化合物，一些胺類化合物，醇類化合物也會受其催化；而這些化合物在接受酚亞硫酸基轉移酵素催化時各有其最佳的酸鹼反應條件。在這個研究中，我們嘗試建立一套新的分析方式，用以分析酚亞硫酸基轉移酵素；我們以一種會產生螢光的物質當受質，利用酚亞硫酸基轉移酵素剛好會催化這種螢光物質的特性；我們便可經由對螢光的測定，來了解酵素的活性。當這套新的分析方式成功的建構之後，我們便利用這套分析方式對不同類別的受質做研究。我們希望經由對：不同pKa及不同鏈長等兩大類的酚類化合物的測試，來了解酚亞硫酸基轉移酵素催化的機制。

EFFECT OF pH ON THE CATALYTIC EFFICIENCY AND SUBSTRATE INHIBITION OF PHENOL SULFOTRANSFERASE Yu-Chen Wang and Yuh-Shyong Yang Department of Biological Science and Technology, National Chiao Tung University, Hsinchu, Taiwan Biological Sulfation, catalyzed by sulfotransferase, plays an important role in the detoxication of xenobiotics. Conjugation with sulfate results in the increase in water solubility, thereby facilitating excretion of hydrophobic compounds. Many important biologically active endogenous compounds are also substrate of sulfotransferase; such conjugation is responsible for regulating of biology activity. Previous researchers found that phenol sulfotransferases catalyze Sulfation of not only phenol compounds, but also amines and alcohols. These compounds have different optimal pH degree for catalyzing by phenol sulfotransferases. The goal of our proposal is trying to understand how this enzyme catalyzes Sulfation of different substrates and how catalytic efficiency and substrate inhibition of this enzyme.Our works are: 1.to set up activity assay using fluorescence spectrophotometer to detect the formation of MU from MUS, which catalyzed by phenol sulfotransferase. 2.to observe different substrates that can inhibit reaction catalyzed by sulfotransferases 3.to understand the catalytic mechanism of phenol sulfotransferase and find a valid inhibitor.