本文選題：青霉素G�；�　切入點：頭孢氨芐　出處：《中國抗生素雜志》2017年10期 　論文類型：期刊論文

【摘要】：目的改善固定化青霉素G�；�(PGA)的酶活穩(wěn)定性,從而提高其重復使用次數(shù)。方法采用模擬法,研究了酶法合成頭孢氨芐過程中影響PGA酶活穩(wěn)定性的一些主要因素。結(jié)果 7-氨基-3-脫乙酰氧基頭孢烷酸(7-ADCA)、苯甘氨酸甲酯(PGM)對固定化PGA表現(xiàn)出了很強的底物抑制作用,而且它們的抑制作用與其濃度幾乎無關(guān)。固定化PGA加入到7-ADCA、PGM溶液后,其酶活迅速降低,但反應時間超過12h后,PGA酶活幾乎保持恒定不變。頭孢氨芐對固定化PGA表現(xiàn)出了產(chǎn)物抑制作用,這種抑制作用主要是由其水解產(chǎn)物造成的。隨著與頭孢氨芐反應時間的延長,固定化PGA的酶活一直持續(xù)降低。當控制反應溫度≤30℃時,固定化PGA表現(xiàn)出良好的酶活穩(wěn)定性。當酶反應液p H值為6.5時,固定化PGA酶活穩(wěn)定性最好。結(jié)論合理控制頭孢氨芐合成反應條件能夠有效改善固定化PGA酶活穩(wěn)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，

本文編號：1650164