牛血清白蛋白辅助交联对苯丙氨酸解氨酶交联酶聚体影响的研究

通过牛血清白蛋白（BSA）辅助交联,制备了牛血清白蛋白苯丙氨酸解氨酶交联酶聚体（BSA-PAL-CLEAs）。优化了BSA-PAL-CLEAs的制备条件,并比较研究了游离酶、苯丙氨酸解氨酶交联酶聚体（PAL-CLEAs）和BSA-PAL-CLEAs的稳定性差异。研究发现,BSA-PAL-CLEAs的最佳制备条件:BSA浓度为5mg/mL,硫酸铵饱和度80%,戊二醛（10%v/v）10μL,交联时间2h,所得BSA-PAL-CLEAs的酶活回收率（25%）是不加BSA时（13%）的1.92倍。稳定性研究表明,BSA-PAL-CLEAs的温度稳定性、储藏稳定性比PAL-CLEAs都有所提高;但是,游离酶、PAL-CLEAs、BSA-PAL-CLEAs的pH稳定性相差不大;BSA-PAL-CLEAs在有机溶剂中的稳定性比PAL-CLEAs有所下降。 

Influence of bovine serum albumin-assisted strategy on preparation of cross-linked enzyme aggregates of Phenylalanine ammonia lyase

Cross-linked enzyme aggregates of phenylalanine ammonia lyase (BSA-PAL-CLEAs) were prepared by using BSA as an additive.Conditions for the preparation of BSA-PAL-CLEAs were optimized, and the stability of free PAL, PAL-CLEAs and BSA-PAL-CLEAs was also evaluated, respectively.The optimized conditions of BSA-PAL-CLEAs preparation were as follows: 80%-saturation ammonia sulfate, 5mg/mL BSA, 10μL glutaraldehyde (10% v/v) and 2h cross-linking time.Under optimized conditions, the activity recovery of prepared BSA-PAL-CLEAs was 1.92-fold than that of PAL-CLEAs.Moreover, the thermal stability and storage stability of BSA-PAL-CLEAs was higher than that of PAL-CLEAs.However, stability against pH of free PAL、PAL-CLEAs and BSA-PAL-CLEAs was similar. In addition, compared with PAL-CLEAs, the stability of BSA-PAL-CLEAs against organic solvents was decreased.