DEAE-D/H树脂固定化氨基酰化酶

选用6种弱碱性大孔树脂固定化氨基酰化酶，结果发现DEAE-D/H（二乙基氨基乙基–二乙烯基苯聚合物）树脂固定化效果较好，固定化酶活1 356.41 U/g。考察了不同酶液浓度下的DEAE–D/H固定化酶活收率。研究发现：酶液浓度115 U/mL时，酶活收率最高，为59.49%。具体分析了此固定化酶拆分乙酰–DL–蛋氨酸的最佳操作条件。结果表明，最佳pH值、温度和Co2+浓度分别为6.5、65℃和5×10－4　mol/L。同时考察了固定化酶的稳定性、再生性。固定化酶连续拆分乙酰-DL-蛋氨酸30天，酶活降为最初的72.6%。失活的固定化酶经洗脱、再生后，酶活达1380.64 U/g，达到新树脂固定化效果，证明载体可重复使用。

Immobilizing aminoacylase on macroporous DEAE-D/H resin

The immobilization of aminoacylase was performed via ionic adsorption on several kinds of weakly basic macroporous anionic resin. Diethylaminoethyl divinyl benzene (DEAE-D/H) was selected as the best immobilization carrier，and the specific activity of aminoacylase was up to 1356.41U/g，much higher than the other carriers. The appropriate concentration of free enzyme solution in immobilization was investigated. The result showed that the optimal concentration of free enzyme solution was 115U/mL; the activity yield was up to 59.49%. When it was used for the optical resolution of N-acetyl-DL-methionine，the optimal pH，temperature and the concentration of Co2+ were 6.5，65℃ and 5×10-4mol/L respectively. Moreover，the enzyme stability was significantly improved，the immobilized enzyme maintained 72.6% initial activity after 30 days of continuous operation. After enzyme inactivation，the protein could be fully desorbed from the resin，and then the resin can be reused，the specific activity of aminoacylase immobilized on regenerative DEAE-D/H was up to 1380.64U/g.