• 作者： 鄭寶樹; 蕭介夫
• 作者服務機構： 國立高雄師範學院化學系
• 中文摘要： 純化後的木瓜?可經由幾種不同的結合方式，成功地共價鍵結於 PVC 衍生物上。由實驗結
  果顯示，其最大酵素結合量可達 47.8 毫克酵素∕克 PVC，相對活性可達溶性酵素的 27.8%，這
  些固定化木瓜?的最適反應 pH 值（pH 6.5～7.0），最安定 pH 值（pH 6.0～7.5），最適反應溫
  度（68°～75°C）及最安定溫度（低於45°C），都較溶性酵素者為高。且固定化木瓜?之最適反應溫
  度及最適反應 pH 值與其最安定之溫度與最安定 pH 值並不完全一致。以重氮鹽活化結合的固定
  化木瓜?為例，在最適反應溫度（75°C）之安定性為最安定溫度（45°C）的 68%，其在工業上應
  用時的最佳生產力最好在 pH 7.0～7.5 及 65°C 下操作。
  將此固定化木瓜?浸置於 6M 尿素 6 小時後，剩餘酵素活性仍大於96%，但相對地溶性酵
  素只剩 16% 之活性。當水解酪蛋白質時，加入0.05M L-脬氨酸（L-cysteine）及0.02M 乙二
  胺四醋酸（EDTA, ethylenediaminetetraacetic acid）時可使活性提高20%，這些固定化木瓜?水
  解酪蛋白質的值（0.2～0.42%）較溶性木瓜?者（為 0.17%）高。
  將含水量為10%的固定化木瓜?在 4°C 下貯存三個月後，活性喪失很少（小於7%），若在
  65°C，pH 7.0下以 batch 方式（每回用一次為半小時）水解酪蛋白質的半衰期為回用 20.5次，
  若欲在較低溫 45°C 或 35°C 下操作，其回用時間為12小時的半衰期分別為 7.8次及 27.0次。G
• 英文摘要： Purified papain was covalently coupled withinsoluble carrier, PVC power, by several differentmethods. The amount of activating reagents,the procedure for the activation of PVC, andthe time for coupling reaction were found toaffect the amount of enzyme immobilized andits relative activity. The maximal amount ofpapain immobilized was 47.8 mg per g of PVCand the maximal relative activity was 27.8%. The optimal pH and the optimal tempera-ture of the immobilized enzyme for the hydro-lysis of casein were higher than those of solublepapain. Stability studies showed that the condi-tion for the best enzyme stability was at tem-perature 45°C and in the pH range between 6.0and 7.5. For the azo derivative, the stabilityat 75°C (the optimal temperature) was only 68%of that of 45°C. The condition for the best pro-ductivity was found to be at 65°C and pH range7.0 to 7.5. Urea, the denaturating reagent of solublepapain, appeared to have little effect on theactivity of immobilized papain. The valuesfor the immobilized enzymes were higher thanshowed those of native papain. The immobilizedpapain no significant loss in enzyme activityafter threemonth storage at 4°C. In the presenceof 0.05M L-cysteine and 0.02M EDTA, thecaseinolytic activity was increased by 20%.If the reuse cycle was 12 hours, the batch typeoperational half-life (casein as substrate)at 45°Cand pH 7.0 was 7.8 cycles; Whereas the half-life at 35°C and pH 7.0 was extended to 27.0cycles. If the reuse cycle was half an hour, thehalf-life at 65°C and pH 7.0 was 20.5 cycles.
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