(A) Removal of SA from AA-labeled 6’-sialyllactoses by Pd-, P224-, and P145-STs was analyzed using HPLC. Symbols for galactose and Neu5Ac are the same as in Fig 2, while glucose is represented by a blue circle. (B) The effects of nucleotides (CMP, CDP, CTP, cytidine, ADP, and ATP) on the α(2,6)-sialidase activity of P145-ST were examined. Reaction mixtures containing 1 mM of each nucleotide were incubated for 2 h. (C) Changes of P145-ST sialidase activities were also analyzed with addition of various concentrations (0.01, 0.05, 0.1, 0.5, 1, and 10 mM) of CMP (filled circle), CDP (triangle), CTP (reverse triangle), and cytidine (filled circle). The reaction mixtures were incubated for 2 h at 37°C. Relative contents (%) of lactose generated by sialidase activity were obtained by the calculation of integrated peak areas (100 × [The areas of lactose peaks]/[Total areas of lactose and sialyllactose peaks]).