Comparison of acetylation activity of expressed vertebrate and amphioxus AANATs. Acetylation activity of GST-bfAANATα, GST-bfAANATδ' (both at pH 9.0) and GST-oAANAT (at pH 6.8) towards various substrates (10 mM) was determined. PUT: putrescine, PPA: propylamine, BTA: butylamine, PEA: phenylethylamine, TRP: tryptamine. Data are presented as the mean ± S.E.M (N = 3). For further details see Methods.