1.4.99.6 DEAE-Toyopearl column chromatography 695533 1.4.99.6 hexahistidine-tagged DadA 748083 1.4.99.6 near homogeneity, two enzymes with different acceptor specificities, fractionation and chromatography techniques 394974 1.4.99.6 Sepharose column chromatography, and gel filtration 724092 1.4.99.6 using a DEAE-Toyopearl column 705545