转谷氨酰胺酶的固定化及其酶学性质的研究

Study on Transgluminase Immobilization and Its Enzymology Nature

转谷氨酰胺酶（TGase；EC2．3．2．13；全称为蛋白质-谷氨酰胺γ-谷氨酰胺基转移酶）是一种能催化多肽或蛋白质的谷氨酰胺残基的γ-羟胺基团（酰基的供体）与许多伯胺化合物（酰基受体）之间的酰基转移反应的酶。

Adopting embedding-crosslinking method to immobilize transglutaminase on sodium alginate and crosslinking with glutaraldehyde solution the optimized immobilization conditions were obtained as follows:the transglutaminase was embedded with sodium alginate with concentration of 4.5%in the volume ratio of 1:1,then 0.2 mol/L CaCl_2 solution was dropped in for immobilization for 1h,after that it was cross-linked by glutaraldehyde(pH=6.0) with concentration of 1.5%at the temperature of 30℃for 2.5h,the activity recovery of transglutaminase could reach 48.83%.Making a comparison of enzymology nature between immobilized enzyme and free enzyme the results showed that the thermal stability and operating stability of the immobilized enzyme was improved,storage time was prolonged,the immobilized enzyme could be used repeatedly for 5 times under the same condition and the residual activity was still kept up 90%.