壳聚糖微球固定化木瓜蛋白酶的特性研究

Studies on Characteristics of Immobilized Papain on Chitosan Microspheres

研究了以壳聚糖微球为载体固定化木瓜蛋白酶的特性 ,包括其形态、外观和酶学性质 .结果表明 :壳聚糖微球固定化木瓜蛋白酶是粒径分布范围较均匀的球形微粒 ;固定化酶的表观米氏常数Kmapp(酪蛋白 )为 0 .0 5 5 % ,是溶液酶的米氏常数Km 的 0 13倍 ;最适pH为 8.0 ;pH稳定性在 7.0左右 ;热稳定性在 15～ 35℃范围内 ;操作半衰期为 2 5d .

Papain was immobilized on chitosan microspheres. The immobilized papain were microspheres with red brown and sole dispersed evenly. The characteristics of the immobilized papain were determined. The results indicated: the K m app (casein) of the immobilized papain was 0.055%, which was 0.13 that of the K m(casein) of the free papain; its optimum pH was 8.0; its pH stability was about 7.0; its thermal stability was 15～35℃; its operation half life time was 25 d.