Diffusional restrictions in glyoxyl-agarose immobilized penicillin G acylase of different particle size and protein loading
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چکیده
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 loadings from 15 to 130 mg/ggel. Internal diffusional restrictions were evaluated for such biocatalysts: Thiele modulus varied from 1.17 for the small particles at the lower protein load to 5.84 for the large particles at the higher protein load. Effectiveness
منابع مشابه
Stabilization of penicillin G acylase from Escherichia coli: site-directed mutagenesis of the protein surface to increase multipoint covalent attachment.
Three mutations on the penicillin acylase surface (increasing the number of Lys in a defined area) were performed. They did not alter the enzyme's stability and kinetic properties; however, after immobilization on glyoxyl-agarose, the mutant enzyme showed improved stability under all tested conditions (e.g., pH 2.5 at 4 degrees C, pH 5 at 60 degrees C, pH 7 at 55 degrees C, or 60% dimethylforma...
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