6.3.2.43 | recombinant C-terminally His-tagged wild-type and mutant enzymes from Escherichia coli strain BL21-CodonPlus (DE3)-RIL by heat treatment at 80°C for 20 min and nickel affinity chromatography. Recombinant nontagged enzyme from Escherichia coli strain BL21(DE3) by heat treatment at 80°C for 20 min, ammonium sulfate fractionation, hydrophobic interaction chromatography, ultrafiltration, and gel filtration |