Topic
Penicillin amidase activity
About: Penicillin amidase activity is a research topic. Over the lifetime, 10 publications have been published within this topic receiving 371 citations.
Papers
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TL;DR: All three isomers of phenylacetyl-aminobenzoic acid are stable in buffer solutions and are suitable as substrates for the simple and sensitive assay of penicillin amidase activity in purified preparations, in bacterial cells as well as in immobilized preparations.
25 citations
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TL;DR: The whole cell immobilization technique has been optimized for different process parameters and the granular catalyst has good mechanical strength, low protein leachability, and high retention of penicillin amidase activity.
24 citations
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2 citations
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TL;DR: The Swatek's method was further simplified for the assay of penicillin amidase activity and no differences in substrate specificity on inactivation with SDS and in alkaline medium between the two amidase forms were observed.
Abstract: The Swatek's method was further simplified for the assay of penicillin amidase activity. The absorbance of colour obtained during determination of 6-aminopenicillanic acid was dependent on concentration of 4-dimethylaminobenzaldehyde and on temperature. Antiodies induced in rabbits with one molecular form of penicillin amidase from E. coli PCM 271 (PA-1 or PA-2) did not cross-react with the other amidase form. No differences in substrate specificity on inactivation with SDS and in alkaline medium between the two amidase forms were observed. Concentrated urea inactivated PA-2 irreversibly and PA-1 reversibly. N-Bromosuccinimide inactivated almost completely only PA-1. Two E. coli PCM 271 strain variants were separated by microbial selection. Each of them produced only one amidase form. Also two amidase forms were found in cells of E. coli ATCC 11105, whereas E. coli ATCC 9636 and ATCC 9637 synthesize only PA-1.
1 citations
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TL;DR: The study of the inhibition of the enzymatic hydrolysis by the reaction products showed that phenylacetic and 7-aminodeacetoxycephalosporanic acids were competitive and non-competitive inhibitors of the penicillin amidase activity respectively.
Abstract: Kinetics of hydrolysis of 7-henylacetamidodeacetoxycephalosporanic acid catalyzed by penicillin amidase as a result of which phenylacetic and 7-aminodeacetoxycephalosporanic acids are formed was studied. The kinetic parameters of the reaction were determined on the basis of both the dependence of the initial rate of enzymatic hydrolysis on the substrate concentration and the analysis of progress kinetic curves of the product accumulation. The values of Km determined by the two methods were equal to (10 +/- 1) muM and kcat (50 +/- 5) sec-1 and (50 +/- 10) sec-1 respectively. The study of the inhibition of the enzymatic hydrolysis by the reaction products showed that phenylacetic and 7-aminodeacetoxycephalosporanic acids were competitive and non-competitive inhibitors of the penicillin amidase activity respectively. The inhibition constants were (55 +/- 8) muM and (12 +/- 1) mM respectively. The physiological role of the enzyme and the effect of the structure of the substrate on the specificity of the enzyme are discussed.
1 citations