3.1.1.58 - 3.1.1.58 140fold, AHU 7165 3.1.1.58 homogeneity 3.1.1.58 recombinant enzyme from Escherichia coli strain DE3 pLysS by cation exchange chromatography and gel filtration 3.1.1.58 recombinant expression of wild-type and mutant enzymes from Escherichia coli 3.1.1.58 recombinant N-terminally His10-tagged enzyme from Escherichia coli strain BL21(DE3) by nickel affinity chromatography, tag cleavage through Factor Xa protease, and ulrafiltration/dialysis