家蚕丝素固定化糖化酶的研究

茧丝经高浓度的氯化钙溶液处理或用稀碱溶液处理后，制成了粉末状丝素和碱化丝素，并以此为载体，用戊二醛为交联剂固定了糖化酶。经对固定化酶性质和动力学参数等的研究表明：丝素能较好地固定糖化酶；每克干粉末状丝素固定化酶的活力约为１８２２ Ｕ， 固定化酶的最适ｐ Ｈ 值比游离酶增加了１０ 到１２５ 个单位，最适温度比游离酶降低了５ ～１０ ℃；固定化酶具有较长的操作半衰期（１４ ～１８ｄ） ；通过米氏常数的测定，粉末状丝素固定化酶的 Ｋｍ １ ＝ ２ ．５３ ×１０ －５ ， 碱化丝素固定化酶的 Ｋｍ ２ ＝３１５ ×１０ － ５ 。实验还发现： 在制备 固定化糖化 酶时， 酶的最适 浓度为 ８ ｍ Ｌ／ Ｌ，戊 二醛的 最适浓 度为０３ ％ 。

Studies on Immobilization of Saccharogenic Amylase With Silk Fibroin

After being dissolved in the high concentration solution of CaCl 2 or treated with alkali solution of low concentration,silk could be prepared into,fibroin powder and fibroin fiber.These fibroins were good materials as carrier of immobilized saccharogenic amylase.By using glutaraldehyde and/or the sorption,saccharogenic amylase was immobilized on the silk fibroin.The experiment indicated that the activity of immobilized saccharogenic amylase was 18.22U each gram;the optimal pH value of the immobilized saccharogenic amylase was 5.25 or 5.5,1.0 to 1.25 lower then that of the free saccharogenic amylase;the optimal temperature was 60～65℃,5～10℃ higher then the free one;the operation half life of the immobilized saccharogenic amylase was 14～18 days;and the Michaelis constant of the saccharogenic amylase immobilized on fibroin powder was Km 1=2.53×10 -5 ,and Km 2(the immobilized enzyme on fibroin fiber)=3.15×10 -5 .The research also showed that the best condition of immobilization was the content of the sascharogenic amylase at 8 mg/L,and the concentration of the glutaraldehyde at 0.3%.