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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TL;DR: The pac gene encoding the penicillin G acylase (PGA) of Bacillus megaterium ATCC 14945 has been cloned in Escherichia coli HB101 using a selective minimal medium containing phenylacetyl-L-leucine instead of L-Leucine.
Abstract: The pac gene encoding the penicillin G acylase (PGA) of Bacillus megaterium ATCC 14945 has been cloned in Escherichia coli HB101 (proA, leuB) using a selective minimal medium containing phenylacetyl-L-leucine instead of L-leucine. The nucleotide sequence of this gene has been determined and contains an open reading frame of 2406 nucleotides. The deduced amino acid sequence shows significant similarity with other β-lactam acylases. Although the PGA of B. megaterium is extracellular, the enzyme produced in E. coli appears to have a cytoplasmic localization.
45 citations
TL;DR: High immobilization yields, operational stability, enzyme loading and support reutilization capacity were obtained, and the operational stabilities of penicillin acylase coupled covalently to the silica gel support and immobilized by a crosslinking procedure using glutaraldehyde were compared.
Abstract: Penicillin acylase (EC 3.5.1.11) was immobilized by covalent binding on a silica gel carrier activated by silanization. High immobilization yields, operational stability, enzyme loading and support reutilization capacity were obtained. The effects of several variables on the activation of the support and on the immobilization method were studied.
Other supports and immobilization methods were assessed for the immobilization of penicillin acylase and compared with the basic process used.
Activity versus temperature, pH, buffer molarity and penicillin concentration profiles were determined and compared for the free, crosslinked and covalently-bound silica carrier penicillin acylase preparations.
The hydrolysis performance of the latter preparation was assessed in a batch basket reactor and the time course of the hydrolysis reaction modelled by a two parameter model equation.
The operational stabilities of penicillin acylase coupled covalently to the silica gel support and immobilized by a crosslinking procedure using glutaraldehyde were also compared.
45 citations
TL;DR: Penicillin G acylase was purified from the cultured filtrate of Arthrobacter viscosus 8895GU and was found to consist of two distinct subunits with apparent molecular weights of 24,000 and 60,000.
Abstract: Penicillin G acylase was purified from the cultured filtrate of Arthrobacter viscosus 8895GU and was found to consist of two distinct subunits with apparent molecular weights of 24,000 (alpha) and 60,000 (beta). The partial N-terminal amino acid sequences of the alpha and beta subunits were determined with a protein gas phase sequencer, and a 29-base oligonucleotide corresponding to the partial amino acid sequence of the alpha subunit was synthesized. An Escherichia coli transformant having the penicillin G acylase gene was isolated from an A. viscosus gene library by hybridization with the 29-base probe. The resulting positive clone was further screened by the Serratia marcescens overlay technique. E. coli carrying a plasmid designated pHYM-1 was found to produce penicillin G acylase in the cells. This plasmid had an 8.0-kilobase pair DNA fragment inserted in the EcoRI site of pACYC184.
45 citations
TL;DR: The immobilization on ionic polymeric beds allowed a significant increase in enzyme stability against the inactivation and inhibitory effects of organic solvents, very likely by the promotion of a certain partition of the organic solvent out of the enzyme environment.
45 citations
TL;DR: In this article, porous hollow silica nanotubes (PHSNTs) were synthesized via a sol-gel route using nano-sized needle-like CaCO3 the inorganic templates were employed as a support for immobilization of penicillin G acylase (PGA) biocatalyst.
Abstract: In this study, porous hollow silica nanotubes (PHSNTs) synthesized via a sol–gel route using nano-sized needle-like CaCO3 the inorganic templates were employed as a support for immobilization of penicillin G acylase (PGA) biocatalyst. The produced PHSNTs were characterized by BET and transmission electron microscopy (TEM). Effect of various factors such as loading temperature and ratio of carries to free PGA (g/mL) on the catalytic activity of the immobilized PGA was also investigated by unitary factor testing method. The results show that under optimized conditions the relative loading amount and the total activity yield of immobilized enzyme (IME) amounts to 97.20% and 88.80%, respectively. Several advantages, i.e. the rapid immobilization of PGA onto PHSNTs, the high tolerability to the pH, the less sensitivity to the temperature and the improved storage stability render PHSNTs potential support materials for enzyme immobilization.
45 citations