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題 名 | Characterization of N-Acetyltransferase in Human Breast Cancer Tissue=人類乳癌組織中乙醯轉移酵素的特性 |
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作 者 | 李昭宏; 陳光偉; 鍾景光; | 書刊名 | 中臺灣醫學科學雜誌 |
卷 期 | 4:3 1999.09[民88.09] |
頁 次 | 頁171-178 |
分類號 | 416.226 |
關鍵詞 | 乳癌組織; N-乙基轉移酵素; 2-aminofluorene; Breast cancer tissues; N-acetyltransferase; P-aminobenzoic acid; |
語 文 | 英文(English) |
中文摘要 | N-乙醯轉移酵素必需要依賴乙醯輔酵素-A所提供的乙醯基來完成乙醯化作用。人類乳房組織中N-乙醯轉移酵素的表現可能是引起乳癌的重要危險因子。本研究是用乳癌病人手術中取得的乳癌組織來探討其對2-aminofluorene及p-aminobenzoic acid的乙醯化的能力。結果顯示乳癌組織中此酵素的分子量是37 kDa,最適宜的反應溫度和pH值分別為37℃和7.5,Km和Vmax值以2-aminofluore作受質分別為0.68 mM和2.116 nmol╱min╱mg protein。0.25 mM 的iodoacetamide可抑制此酵素活性的52%,但濃度高至1 mM時則可抑制達92%。檢測中也發現Zn�ワMCa�ョA對此酵素抑制性最強。這項研究是第一次說明國人乳癌組織中乙醯轉移酵素的生化特性。 |
英文摘要 | Genotype-dependent expression of acetyl coenzyme A-dependent N-acetyltransferase (NAT) activity, which catalyzes N-acetylation of arylamine, may be an important risk factor in the initiation of breast cancer. Surgical tissue samples from breast cancer tumors were investigated for NAT activity toward p-aminobenzoic acid and the arylamine carcinogen 2-aminofluorene. The enzyme from breast cancer tissues showed a molecular mass of 37 kDa. The optimal temperature for the enzyme activity was 37℃ and the optimal pH was 7.5 for the 2-aminofluorene tested. The Km and Vmax value for 2-aminofluorene was determined to be 0.628 mM and 2.116 nmol/min/mg protein, respectively. The NAT activity was reduced 80% by iodoacetamide at 0.5 mM. Among a series of divalent cations and salts, Zn�� and Ca�� were the most potent inhibitors. This is the first demonstration of NAT characteristics in breast cancer tissue from Chinese women with breast cancer. |
本系統中英文摘要資訊取自各篇刊載內容。