• 作者： 林耀輝
• 作者服務機構： 中央研究院植物研究所
• 中文摘要： 「從水稻（Oryza sativa）及綠豆（Phaseolus radiatus）發芽種子抽取出的粗染色質含有聚合NAD的活性。水稻酵素的比活性是每mg蛋白質每三小時有4798 Picomoles而綠豆酵素的比活性是每mg蛋白質每三小時4278 Picomoles“這兩個數值和老鼠胰臟細胞核的比活性差不多“該酵素需要還原劑，例如2-mercaptoethanol，來保護它的活性而最適酸度約為pH 7.4“氯化鎂在本實驗條件下略為促進酵素活性。兩種植物體的NAD聚合之活性都受nicotinamide抑制，不過程度上沒有動物細胞體那麼敏惑。由不同發芽時間得到的水稻芽或綠豆芽抽出之染色質的比酵素活性可以看出聚台NAD所產生的聚合分子和芽之生長速率有負相關關係，可能正如其他研究者以動物細胞核做材料所提的建議相同，就是：聚合分子的形成抑制去氧核糖核酸之合成“酵素系統本身及反應產物的若干性質大致和報告過的poly（ADP-Ribose）系統相符合“
• 英文摘要： Crude chromatin of germinating seeds of Oryza sativa (rice) and Phaseolusradiatus(green grain) shows NAD-incorporating activity. Rice enzyme has aspecific activity of 4798 picomoles per mg protein per 3 hours while that of一green grain enzyme is 4278 picomoles per mg protein per 3 hours. Both valuesare comparable to that of rat spleen nuclei．The enzyme reguires 2-merca-ptoethanol for protection of its activity and has a optimal pH around 7.4.MgCl2 stimulates slightly the enzymic activity in the assay system used.The NAD-incorporating activity of chromatin of both rice and green grain,although less sensitive to nicotinamide than that of animal systems, is inhi-bited by nicotinamide．Changes of specific activity of chromatin isolatedfrom green grain at various germinating times suggest that the formationof a polymer from NAD seems to have negative correlation with growthrate of green grain seedlings. In turn,. it seems to have negative relationshipwith DNA synthesis as proposed by other researchers using rat liver nuclei.Properties of enzyme system and reaction products formed are mostly inagreement with those of poly (ADP-Ribose) system in animal cells.
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