โ Scribed by Dilek Kazan; Altan Erarslan
No coin nor oath required. For personal study only.
The stabilisation of Escherichia coli penicillin G acylase (PGA) by dextran polymers (of molecular weight 11.5, 37.7 and 71 kDa) was studied. The inactivation of both the native and dextrancontaining enzyme preparations obeyed ยฎrst-order kinetics at the temperature and pH values studied. The optimal concentrations of dextran polymers of molecular weight 11.5, 37.7 and 71 kDa stabilising PGA against inactivation were 50, 20 and 7.5 mmol dm ร3 respectively. Dextran 11500 (11.5 kDa) gave 100-fold protection of PGA against thermal inactivation of enzyme above 50 ยฐC. The kinetic constants of the enzyme were slightly altered, but temperature and pH proยฎles were not altered by the dextrans.
๐ SIMILAR VOLUMES
## Abstract Highโlevel expression of recombinant penicillin acylase (PAC) using the strong __trc__ promoter system in __Escherichia coli__ is frequently limited by the processing and folding of PAC precursors (proPAC) in the periplasm, resulting in physiological stress and inclusion body formation
## Abstract The effects of organic cosolvents on the synthesis of ampicillin from phenylglycine methyl ester (PGME) and 6โamino penicillanic acid (6โAPA) using immobilized __Bacillus megaterium__ penicillin G acylase have been examined. Several cosolvents were tested for their influence on the enzy