Fig. 3.

Hydroxyapatite column elution profile of E. coli Ung and Ndk activity. Hydroxyapatite column chromatography of Fraction III and standard assays for Ung (open circles) and Ndk (filled circles) were performed as described in Materials and Methods. Protein concentration (open squares) and potassium phosphate concentration (filled squares) were determined as described in Materials and Methods. Fractions corresponding to the peak of Ung (I) and Ndk (II) activity are indicated by vertical arrows.