A single amino acid substitution converts gamma-glutamyltranspeptidase to a class IV cephalosporin acylase (glutaryl-7-aminocephalosporanic acid acylase).
نویسندگان
چکیده
The aspartyl residue at position 433 of gamma-glutamyltranspeptidase of Escherichia coli K-12 was replaced by an asparaginyl residue. This substitution enabled gamma-glutamyltranspeptidase to deacylate glutaryl-7-aminocephalosporanic acid, producing 7-aminocephalosporanic acid, which is a starting material for the synthesis of semisynthetic cephalosporins.
منابع مشابه
Isolation and characterization of a pseudomonas strain producing glutaryl-7-aminocephalosporanic Acid acylase.
Several screening methods were developed for the selection of Pseudomonas strains capable of hydrolyzing glutaryl-7-aminocephalosporanic acid to 7-aminocephalosporanic acid. An isolate exhibiting high acylase activity, designated BL072, was identified as a strain of Pseudomonas diminuta. It grew optimally at pH 7 to 8 and at a temperature of 32 to 40 degrees C, but acylase activity was highest ...
متن کاملBiochemical characterization of a glutaryl-7-aminocephalosporanic acid acylase from Pseudomonas strain BL072.
Pseudomonas strain BL072 produces an acylase enzyme active in hydrolyzing glutaryl-7-aminocephalosporanic acid to 7-aminocephalosporanic acid. This acylase was purified by column chromatography and gel electrophoresis. The native acylase was composed of two subunits of approximately 65 and 24 kDa, though some heterogeneity was seen in both the native acylase and its small subunit. The isoelectr...
متن کاملStructure of a class III engineered cephalosporin acylase: comparisons with class I acylase and implications for differences in substrate specificity and catalytic activity.
The crystal structure of the wild-type form of glutaryl-7-ACA (7-aminocephalosporanic acid) acylase from Pseudomonas N176 and a double mutant of the protein (H57βS/H70βS) that displays enhanced catalytic efficiency on cephalosporin C over glutaryl-7-aminocephalosporanic acid has been determined. The structures show a heterodimer made up of an α-chain (229 residues) and a β-chain (543 residues) ...
متن کاملEffects of an extra Trp113Tyr substitution on yeast D-amino acid oxidase variant
Background b-Lactam antibiotics (cephalosporins and penicillins) are used in clinical practice to combat microbial infections. Commercial cephalosporins are all semi-synthetic and chemically derived from 7-aminocephalosporanic acid (7-ACA), a cephem nucleus that is traditionally produced by multi-step chemical reactions from cephalosporin C (CPC). However, the procedures are environmentally dam...
متن کاملActive site residues of cephalosporin acylase are critical not only for enzymatic catalysis but also for post-translational modification.
Cephalosporin acylase (CA) is a recently identified N-terminal hydrolase. It is also a commercially important enzyme in producing 7-aminocephalosporanic acid (7-ACA), a backbone chemical in synthesizing semi-synthetic cephalosporin antibiotics. CA is translated as an inactive single chain precursor, being post-translationally modified into an active enzyme. The post-translational modification t...
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ورودعنوان ژورنال:
- Applied and environmental microbiology
دوره 70 10 شماره
صفحات -
تاریخ انتشار 2004