1.13.11.71	a small amount of recombinant, catalytically inactive His-tagged enzyme from Escherichia coli strain BL21-Gold (DE3) by cobalt affinity chromatography	
1.13.11.71	native enzyme 9.5fold to homogeneity by ammonium sulfate fractionation and gel filtration	
1.13.11.71	recombinant His-tagged enzyme from Escherichia coli strain BL21-Gold (DE3) by cobalt affinity chromatography