疏水吸附性载体上附加基团对天冬氨酸酶性质的影响

6-氨基己酸和四乙烯基五胺通过高碘酸氧化法分别引入到邻甲苯胺基琼脂珠(TA)衍生物上,得到CTA和ATA,天冬氨酸酶在pH5.5,0.1mol/L磷酸缓冲液中,0.5mol/L KCl存在下通过疏水吸附固定化在TA,CTA和ATA上。结果表明三种固定化酶活力回收均达90％以上,同TA-天冬氨酸酶相比,CTA-酶,ATA-酶的最适pH,pH稳定性等均有所改变,其中ATA-酶的热稳定性,使用稳定性增强,CTA-酶的稳定性降低。

Effect of the Group Attached to Hydrophobic Matrix on the Properties of Aspartase

6-Amino-n-caproic acid and tetraethylenepentamine were introduced into O-toluidine-agar bead (TA) oxidized with NaIO and the products designated as CTA, ATA were obtained. The hydrophobic adsorption of L-aspartase to TA, CTA and ATA was carried out at 4℃ in a 0.1mol/L phosphate buffer of pH5.5 containing 0.5mol/L KCl (the added protein amount was 16.4mg/g suction-dried agar bead). The results show that three types of immobilized aspartases have a very high recovery (over 90%) in activity. The optimum pH, pH stability, thermostability and operational stability of immobilized aspartases were studied. With comparision to TA-aspartase, the stability of ATA-aspartase is considerably increased and that of CTA-aspartase is decreased.