Figure 4.
pH-dependency of the methylating activity of the zebrafish COMT with (A) 2-hydroxy-E1 and (B) dobutamine as substrate. The enzymatic assays were carried out under standard assay conditions as described in Materials and Methods, using different buffer systems as indicated. The data represent calculated mean ± SD derived from three experiments. Statistical significance versus the activity of control is indicated by * with p<0.001 or # with p>0.001 for the 2-hydroxy-E1- or dobutamine-sulfating activity of the zebrafish COMT. The sample size (n) analyzed was 8.