- 作者: 陳淑真
- 作者服務機構: 國立陽明醫學院生化科
- 中文摘要: 黃麴毒素B1還原酵素存在於細胞質可溶部分,可負責催化還原黃麴毒素B1形成黃麴毒醇。此酵素於一至二天大之小雞肝臟內之活性遠較其他二種對黃麴毒素B1,之毒性及致癌性敏感程度也很強之小鴨及老鼠肝臟中者為高。 小雞肝臟黃麴毒素B1還原酵素之一般性質已大致被鑑定。酵素反應之最適pH為6.0。此酵素置於室溫一小時仍很穩定。在-70°C保存三個月以上仍保有完全之活性。硫醇根抑制物p-Hydroxymercuribenzoate(0.5 mM)可抑制大約50%之酵素活性,但N-Ethylmaleimide及Iodoacetamide則無明顯影響。硫醇化合物對此酵素亦無明顯影響。
- 英文摘要: Aflatoxin B1 reductase, a cytoplasmic enzyme catalyzing the reduction of aflatoxin B1 to aflatoxicol, was studied in the livers of three susceptible species: rat, young chick and duckling. The liver of 1-2 days old chick possessed the highest enzyme activity, which was about 3 and 11 times that of the livers of duckling and adult male rat respectively. The general properties of the crude enzyme preparation from chicken liver were characterized. The optimal pH for the enzyme reaction was at pH 6.0. The enzyme was stable at room temperature for 1 hour and remained fully active after storage at -70蚓 for more than 3 months. The thiol-blocking reagent p-hydroxymercuribenzoate (0.5 mM) inhibited about 50% of the enzyme activity, whereas N-ethylmaleimide and iodoacetamide (0.5 mM) had no significant effect. The thiol reagent 2-merca-ptoethanol, cysteine and dithiothreitol also did not show significant effect on the enzyme under the present experimental conditions.
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