Enzyme activity of GST-bfAANATα and GST-bfAANATδ'. A. pH optimum. Data are presented as the percent of maximal activity for each protein. Data represent results of two independent experiments with the difference of means < 5%. For comparison, data for ovine and yeast AANAT from a previous study are shown . B. Inhibition of GST-bfAANATα by bisubstrate inhibitor CoA-T. C. Acetylation activity of GST-bfAANATα towards tryptamine measured at different temperatures to determine the optimum. Data represent results of two independent experiments with the difference of means < 5%. Data in B are presented as the mean ± S.E.M (N = 3). For further details see Methods.