Showing papers on "Penicillin amidase published in 2022"
TL;DR: Penicillin G acylase (PGA) from Escherichia coli was immobilized on vinyl sulfone (VS) agarose, and the enzyme failed at all pH values using 50 mM of buffer, while the progressive increase of ionic strength permitted its rapid immobilization under all studied pH values as mentioned in this paper .
Abstract: Penicillin G acylase (PGA) from Escherichia coli was immobilized on vinyl sulfone (VS) agarose. The immobilization of the enzyme failed at all pH values using 50 mM of buffer, while the progressive increase of ionic strength permitted its rapid immobilization under all studied pH values. This suggests that the moderate hydrophobicity of VS groups is enough to transform the VS-agarose in a heterofunctional support, that is, a support bearing hydrophobic features (able to adsorb the proteins) and chemical reactivity (able to give covalent bonds). Once PGA was immobilized on this support, the PGA immobilization on VS-agarose was optimized with the purpose of obtaining a stable and active biocatalyst, optimizing the immobilization, incubation and blocking steps characteristics of this immobilization protocol. Optimal conditions were immobilization in 1 M of sodium sulfate at pH 7.0, incubation at pH 10.0 for 3 h in the presence of glycerol and phenyl acetic acid, and final blocking with glycine or ethanolamine. This produced biocatalysts with stabilities similar to that of the glyoxyl-PGA (the most stable biocatalyst of this enzyme described in literature), although presenting just over 55% of the initially offered enzyme activity versus the 80% that is recovered using the glyoxyl-PGA. This heterofuncionality of agarose VS beads opens new possibilities for enzyme immobilization on this support.
3 citations
TL;DR: In this article , high performance computing has been used for molecular modeling of penicillin acylase interaction with 6-aminopenicillanic acid (6-APA) to assess whether the wild-type enzyme or its mutants could possess β-lactamase activity.
Abstract: High-performance computing has been used for molecular modeling of penicillin acylase interaction with a penicillin nucleus 6-aminopenicillanic acid (6-APA) to assess whether the wild-type enzyme or its mutants could possess β-lactamase activity. Applying parallel hybrid GPU/CPU computing technologies for metadynamics calculations with the PLUMED library in conjunction with AMBER software suite it has been shown that trace amounts of wild-type penicillin acylase6-APA complexes leading to a β-lactamase reaction can be formed. Higher β-lactamase activity can be observed in enzyme mutants by introducing charged residue in the substrate binding pocket and its proper positioning with respect to a catalytic nucleophile, including stabilization of the tetrahedral intermediate in the oxyanion hole. Thus, it has been shown that the certain mutations facilitate the orientation of the substrate required for the manifestation of β-lactamase activity in the penicillin acylase active center.