Topic
Penicillin amidase
About: Penicillin amidase is a research topic. Over the lifetime, 576 publications have been published within this topic receiving 15563 citations. The topic is also known as: penicillin amidohydrolase & ampicillin acylase.
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15 citations
Journal Article•
TL;DR: Penicillin amidase from Proteus rettgeri was purified 580-fold by a four-step chromatographic procedure and it was found that the purified preparation contains 53% of the enzyme.
Abstract: 1. Penicillin amidase from Proteus rettgeri was purified 580-fold by a four-step chromatographic procedure. Titration with phenylmethanesulphonyl fluoride showed that the purified preparation contains 53% of the enzyme. 2. The molecular weight of the amidase was found to be 65.000. The enzyme is strongly inhibited by N-bromosuccinimide and zinc ions. It hydrolyses penicillins, cephalosporins and some synthetic substrates, and in addition it catalyses synthesis of ampicillin from methyl ester of phenylglycine and 6-aminopenicillanic acid. 3. The immobilized amidase obtained by copolymerization of the chemically modified enzyme with acrylamide was applied for preparative hydrolysis of benzylpenicillin.
15 citations
TL;DR: It is shown that the penicillin-splitting amidase from Streptomyces lavendulaedescribed by Batchelor, Chain, Richards and Rolinson is a substrate for acylase-like reactions in E. coli.
Abstract: IT is known that many fungi and some bacteria produce penicillin-splitting amidases or acylases1,2. With the exception of the amidase from Streptomyces lavendulaedescribed by Batchelor, Chain, Richards and Rolinson3, few details have been published about these enzymes.
15 citations
TL;DR: In toluene, Celite R-640 is able to maintain the water activity constant within broad ranges of water concentrations, and the a w values are strongly related to the original hydration of the Celite batches, but prolonged drying confers comparable and reproduced properties to the different batches.
Abstract: The study describes how Celite R-640 adsorbs liquid water in toluene and vapour water from a gas phase. In toluene, Celite R-640 is able to maintain the water activity ( a w ) constant within broad ranges of water concentrations. The a w values are strongly related to the original hydration of the Celite batches, but prolonged drying confers comparable and reproducible properties to the different batches. The use of Celite R-640 in controlling the hydration and activity of covalently immobilised PGA in toluene is reported.
15 citations
TL;DR: The effect of external mass transfer resistance on the overall reaction rate of the immobilized whole cell penicillin amidase of E. coli in a recirculation batch reactor was investigated and the correlation proposed by Chilton and Colburn represented adequately the experimental data.
Abstract: The effect of external mass transfer resistance on the overall reaction rate of the immobilized whole cell penicillin amidase of E. coli in a recirculation batch reactor was investigated. The internal diffusional resistance was found negligible as indicated by the value of effectiveness factor, 0.95. The local environmental change in a column due to the pH drop was successfully overcome by employing buffer solution. The reaction rate was measured by pH-stat method and was found to follow the simple Michaelis-Menten law at the initial stage of the reaction. The values of the net reaction rate experimentally determined were used to calculate the substrate concentration at the external surface of the catalyst pellet and then to calculate the mass transfer coefficient, k(L), at various flow rates and substrate concentrations. The correlation proposed by Chilton and Colburn represented adequately the experimental data. The linear change of log j(D) at low log N(Re) with negative slope was ascribed to the fact that the external mass transfer approached the state of pure diffusion in the limit of zero superficial velocity.
15 citations