青霉素G酰化酶的亚基重组

青霉素G酰化酶在半合成β-内酰胺类抗生素工业中催化关键反应。将来源于Esherichia coli的α亚基分别与Kluyvera citrophila,Providencia rettgeri,Alcaligenes faecalis的β亚基重组得到三种杂合酶,杂合酶表达量随野生型PGA同源性的减小而降低,E.coli和A.faecalis氨基酸序列的相同性低至41%,其杂合酶仍然具有水解3-苯乙酰胺-6-硝基苯甲酸的活力。

Cross-species heterodimers of penicillin G acylase

Penicillin G acylase(PGA,E.C.3.5.1.11) plays a central role in semi-synthetic β-lactam antibiotics industry.Three cross-species penicillin G amidase genes coding for an α-peptide from Esherichia coli and a β-peptide from Kluyvera citrophila,Providencia rettgeri,Alcaligenes faecalis,respectively,has been constructed and cloned in E.coli.It was found that hydrolysis activity was kept in the hybrid enzymes.The expression level of hybrid enzymes reduced with amino acid(aa)identity of wild type PGA decreasing.Though the PGA of E.coli and A.faecalis share 41% aa identity,the hybrid enzyme of them expressed in E.coli was active.