固定化青霉素G酰化酶合成头孢氨苄过程中酶活稳定性研究

发布时间：2018-03-22 20:01

  本文选题：青霉素G酰化酶　切入点：头孢氨苄　出处：《中国抗生素杂志》2017年10期 　论文类型：期刊论文

【摘要】：目的改善固定化青霉素G酰化酶(PGA)的酶活稳定性,从而提高其重复使用次数。方法采用模拟法,研究了酶法合成头孢氨苄过程中影响PGA酶活稳定性的一些主要因素。结果 7-氨基-3-脱乙酰氧基头孢烷酸(7-ADCA)、苯甘氨酸甲酯(PGM)对固定化PGA表现出了很强的底物抑制作用,而且它们的抑制作用与其浓度几乎无关。固定化PGA加入到7-ADCA、PGM溶液后,其酶活迅速降低,但反应时间超过12h后,PGA酶活几乎保持恒定不变。头孢氨苄对固定化PGA表现出了产物抑制作用,这种抑制作用主要是由其水解产物造成的。随着与头孢氨苄反应时间的延长,固定化PGA的酶活一直持续降低。当控制反应温度≤30℃时,固定化PGA表现出良好的酶活稳定性。当酶反应液p H值为6.5时,固定化PGA酶活稳定性最好。结论合理控制头孢氨苄合成反应条件能够有效改善固定化PGA酶活稳定性。
[Abstract]:Objective to improve the activity stability of immobilized penicillin G acylase (PGA) and to increase its reuse times. The main factors affecting the activity stability of PGA in the process of enzymatic synthesis of cefalexin were studied. Results 7Amino-3-deacetylcefloxane acid 7-ADCAA and phenylglycine methyl ester PGM showed a strong inhibitory effect on immobilized PGA. Moreover, their inhibitory effect was almost independent of their concentration. When immobilized PGA was added to 7-ADCAPGM solution, its enzyme activity decreased rapidly. However, after the reaction time was more than 12 h, the activity of PGAase was almost constant. Cefalexin showed a product inhibitory effect on immobilized PGA, which was mainly caused by the hydrolytic product. With the prolongation of the reaction time with Cefalexin, Cefalexin showed an inhibitory effect on the immobilized PGA. The enzyme activity of immobilized PGA decreased continuously. When the reaction temperature was less than 30 鈩，

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