Prophenol oxidase A3 in Drosophila melanogaster: activation and the PCR-based cDNA sequence

• Published in: Biochemical genetics Vol. 41; no. 5-6; pp. 151 - 163
• Main Authors: Asada, Nobuhiko, Yokoyama, Genta, Kawamoto, Nobuko, Norioka, Shigemi, Hatta, Takashi
• Format: Journal Article
• Language: English
• Published: United States Springer Nature B.V 01.06.2003
• Subjects: Amino Acid Sequence; Amino acids; Animals; Bacteria; Base Sequence; Binding sites; Catechol Oxidase - genetics; Catechol Oxidase - isolation & purification; Catechol Oxidase - metabolism; DNA, Complementary - genetics; Drosophila melanogaster - enzymology; Drosophila melanogaster - genetics; Electrophoresis, Polyacrylamide Gel; Endopeptidases - pharmacology; Enzyme Activation - drug effects; Enzyme Precursors - genetics; Enzyme Precursors - isolation & purification; Enzyme Precursors - metabolism; Insects; Isoenzymes - genetics; Isoenzymes - isolation & purification; Isoenzymes - metabolism; Molecular Sequence Data; Phenols; Polymerase Chain Reaction; Sequence Alignment; Sequence Homology, Amino Acid
• ISSN: 0006-2928; 1573-4927
• DOI: 10.1023/A:1023325610300

Phenol oxidase exists in Drosophila hemolymph as a prophenol oxidase, A1 and A3, that is activated in vivo with a native activating system, AMM-1, by limited proteolysis with time. The polypeptide in purified prophenol oxidase A3 has a molecular weight of approximately 77,000 Da. A PCR-based cDNA sequence coding A3 has 2501 bp encoding an open reading frame of 682 amino acid residues. The potential copper-binding sites, from Trp-196 to Tyr-245, and from Asn-366 to Phe-421, are highly homologous to the corresponding sites in other invertebrates. The availability of prophenol oxidase cDNA should be useful in revealing the biochemical differences between A1 and A3 isoforms in Drosophila melanogaster that are refractory or unable to activate prophenol oxidase.