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 effect of methanol on the Penicillin G acylase structure could be cleared out by increasing the stability of the enzyme derivative or by “fixing” the enzyme conformation in the presence of the organic solvent during the immobilization process.
71 citations
TL;DR: Penicillin G acylase from Escherichia coli was immobilized on Eupergit C with different enzyme loading and demonstrated that the immobilized enzyme molecules on average had turnover rates much lower than that of the dissolved enzyme.
Abstract: Penicillin G acylase from Escherichia coli was immobilized on Eupergit® C with different enzyme loading. The activity of the immobilized preparations was assayed in the hydrolysis of penicillin G and was found to be much lower than would be expected on the basis of the residual enzyme activity in the immobilization supernatant. Active-site titration demonstrated that the immobilized enzyme molecules on average had turnover rates much lower than that of the dissolved enzyme. This was attributed to diffusion limitations of substrate and product inhibition. Indeed, when the immobilized preparations were crushed, the activity increased from 587 U g -1 to up to 974 U g -1 . The immobilized preparations exhibited up to 15% lower turnover rates than the dissolved enzyme in cephalexin synthesis from 7-ADCA and D-(-)-phenylglycine amide. The synthesis over hydrolysis ratios of the immobilized preparations were also much lower than that of the dissolved enzyme. This was partly due to diffusion limitations but also to an intrinsic property of the immobilized enzyme because the synthesis over hydrolysis ratio of the crushed preparations was much lower than that of the dissolved enzyme.
70 citations
Journal Article•
66 citations
TL;DR: Collagen was used as carrier for the immobilization of invertase, lysozyme, urease, glucose oxidase, penicillin amidase, Penicillin Amidase, and glucose isomerase.
Abstract: Collagen was used as carrier for the immobilization of invertase, lysozyme, urease, glucose oxidase, penicillin amidase, and glucose isomerase. Immobilization was accomplished by either impregnation of a preswollen collagen membrane with enzyme solution or electrocodeposition of collagen and enzyme from a collagen dispersion containing dissolved enzyme. The collagen-enzyme complexes prepared are in membrane form.
Membranous collagen-enzyme complexes were used to construct biocatalytic reactors such as the capillaric coil modular reactor. Such biocatalytic reactors were used in a recirculation system for the conversion of substrates. The biocatalytic reactors showed initial decreases of activity to stable limits which are maintained over a large number of reactor volume replacements. The stable limits correspond to approximately 35% of the initial activities for lysozyme and invertase, 25% for urease, 15% for glucose oxidase.
The mechanism of complex formation between collagen and enzyme involves multiple salt linkages, hydrogen bonds, and van der Waals interactions. This protein-protein interaction which leads to stable complexes by both impregnation and electrocodeposition processes is unique among the enzyme immobilization methods currently available.
65 citations
TL;DR: The design and synthesis of novel self-immolative spacer systems aiming at the release of phenol-containing compounds and their utility was illustrated by the preparation of original fluorogenic substrates of penicillin amidase whose strong fluorescence is unveiled through enzyme-initiated domino reactions.
61 citations