Endonuclease activity of phenol oxidase from Musca domestica larvae.
Phenol oxidase (PO), a copper-containing enzyme with oxygenase activity, can convert mono- or diphenol into quinone and plays an important role in the arthropod melanization reaction. Here, we report a new property of PO from Musca domestica larvae: a thermotolerant endonuclease activity, by which PO can degrade plasmid DNA even after being heated to 80 degrees C for 20 min. We cloned PO cDNA, constructed the expression vector pVAX1-PO, and expressed it in HeLa cells. The expression product showed the same properties as purified PO. Our data indicate that PO is a bifunctional enzyme, exhibiting both oxygenase and endonuclease activity, suggesting new roles for this important molecule in the innate responses of M. domestica.
Sun
Shaoguang
S
Department of Biochemistry and Molecular Biology, China Agricultural University, Beijing 100094, China.
Liu
Weiquan
W
Wang
Jigui
J
Yang
Shuyan
S
Gu
Ling
L
Hong
Yan
Y
Shang
Dan
D
Wang
Benxu
B
Su
Xiaoming
X
Qi
Shunzhang
S
D000818:Animals; D015153:Blotting, Western; D003001:Cloning, Molecular; D004720:Endonucleases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D015870:Gene Expression; D005822:Genetic Vectors; D006367:HeLa Cells; D006793:Houseflies / Q000201:enzymology* / Q000235:genetics; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007814:Larva / Q000201:enzymology; D014442:Monophenol Monooxygenase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D010957:Plasmids / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D013696:Temperature
D011994:Recombinant Proteins; D014442:Monophenol Monooxygenase; D004720:Endonucleases