固定化胰蛋白酶及其用于制备酪蛋白磷酸肽(CPPs)的实验研究

STUDY ON IMMOBILIZED TRYPSIN AND ITS USING FOR PREPARATION OF CPPS

以壳聚糖为载体、戊二醛为交联剂进行胰蛋白酶的固定化实验。实验条件:壳聚糖0.2g,交联剂浓度9％,交联温度30℃,交联时间2h,加酶量0.8mg,pH值8.0,固定化时间1h,固定化温度4℃。实验结果表明:固定化胰蛋白酶的最适温度为55℃,比溶液酶提高了15℃,活力回收率为50.8％。此外进行了利用固定化胰蛋白酶制备酪蛋白磷酸肽(CPPs)的实验,测定了其持钙能力,发现CPPs浓度为0.5g/L和0.2g/L时能完全阻止磷酸钙沉淀生成,浓度为0.1g/L时能使磷酸钙沉淀生成推迟20min,浓度为0.06g/L和0.04g/L时能使磷酸钙沉淀生成推迟10min。

The optimum conditions for immobilization were that 0. 2g chitosan interconnected with 3mL 9% glutaraldehyde , crosslinked temperature 30C, crosslinked time 2h, the amount of trypsin is 0. 8mg, pH8. 0, immobilization time 1h, immobilization temperature 4C. Under above conditions, activity retentive value was 50. 8%. The optimum temperature of immobilized trypsin was 55C , that of nature trypsin was 40C. The effect of CPPs on retarding the formation of calcium phosphate was monitored. 0. 2g/L and 0. 5g/L of CPPs prevented the precipitation of calcium phosphate during one hour of reaction. 0.1g/L CPPs can retard the formation of calcium phosphate 20 minutes.