Isolation and characterization of an arylalkylamine N-acetyltransferase from Drosophila melanogaster.
The enzyme arylalkylamine N-acetyltransferase (aaNAT) catalyzes the rate-limiting step in melatonin formation in the vertebrate pineal gland. Numerous attempts to purify this highly unstable enzyme from vertebrates have been unsuccessful. Here, we report the purification of an aaNAT enzyme from Drosophila melanogaster, using a radioenzymatic activity assay and column chromatography. The isolated 29.5-kDa protein acetylates tryptamine, dopamine and serotonin with affinities of 0.89 to 0.97 mM, respectively. This suggests that the identified aaNAT may be involved in melatonin synthesis and sclerotization as well as in neurotransmitter catabolism in insects.
D000595:Amino Acid Sequence; D000818:Animals; D001191:Arylamine N-Acetyltransferase / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D002845:Chromatography; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D004331:Drosophila melanogaster / Q000201:enzymology*; D017886:Durapatite; D007202:Indicators and Reagents; D007700:Kinetics; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010446:Peptide Fragments / Q000737:chemistry / Q000302:isolation & purification; D013379:Substrate Specificity
D007202:Indicators and Reagents; D010446:Peptide Fragments; D017886:Durapatite; D001191:Arylamine N-Acetyltransferase