The catalytic properties of penicillin G acylase (PGA) from Escherichia coli in kinetically controlled synthesis of β-lactam antibiotics are negatively affected upon immobilization on hydrophobic acrylic carriers. Two strategies have been here pursued to improve the synthetic performance of PGA immobilized on epoxy-activated acrylic carriers. First, an aldehyde-based spacer was inserted on the ...

In biocatalytic processes, the use of free enzymes is often limited due to lack long-term stability and reusability. To counteract this, can be crystallized then immobilized, generating cross-linked enzyme crystals (CLECs). As mechanical activity CLECs are crucial, different penicillin G acylases (PGAs) from Gram-positive organisms have proven promising candidates for industrial production new ...

Significant advances have been made in the structure-based engineering of enzymes useful for beta-lactam antibiotic production. Structure-based engineering of penicillin G acylase and cephalosporin acylase has resulted in improved enzymes for use in enzymatic production processes. The structures of many other enzymes that could be used in the production of beta-lactam antibiotics, such as enzym...

Particle size and enzyme protein loading are design parameters of enzyme immobilization affecting biocatalyst performance that can be varied within broad margins. Their effect on mass transfer limitations at different bulk penicillin G concentrations has been studied with glyoxyl agarose immobilized penicillin G acylase biocatalysts of average particle size of 5·10m and 10·10m at protein loadin...

Penicillin acylase proteins are amidohydrolase enzymes that cleave penicillins at the amide bond connecting the side chain to their beta-lactam nucleus. An unannotated protein from Bacillus subtilis has been expressed in Escherichia coli, purified and confirmed to possess penicillin V acylase activity. The protein was crystallized using the hanging-drop vapour-diffusion method from a solution c...

Residue phenylalanine 71 of the β-chain of penicillin acylase from E. coli is involved in substrate binding and chiral discrimination of its enantiomers. Different amino acid residues have been introduced at position βF71, and the mutants were studied with respect to their enantioselectivity and substrate specificity. Some mutants demonstrated remarkably improved catalytic activity. Moreover, m...

A new penicillin acylase was isolated by cloning and functional screening of DNA isolated from a sand soil enrichment culture. Sequence analysis of this enzyme, PAS2, revealed homology to a group of prominent penicillin G acylases, including the intensively studied enzyme of Escherichia coli ATCC 11105. Accordingly, PAS2 was found to be an Ntn-hydrolase with an N-terminal serine as the catalyti...