Purification and characterization of phenoloxidase from the hemocytes of Eurygaster integriceps (Hemiptera: Scutelleridae).
Insects protect themselves from microbial invaders by two main immune activities, namely the cellular and humoral reactions. Phenoloxidases are oxidative enzymes that have an important role in both cell-mediated and humoral immunity. In this study, the purification and biochemical characterization of a phenoloxidase from the hemocytes of the Sunn pest Eurygaster integriceps Puton (Hemiptera: Scutelleridae) were carried out. After the final purification step, the enzyme was purified 7.31-fold with a recovery of 3.94% and a specific activity of 4.95U/mg protein. Results of the biochemical characterization showed that the purified phenoloxidase has a maximum activity at pH 6 and at 30-35°C and is stable for 24-36h. Divalent cations such as Ca(2+) and Cu(2+) significantly increased the enzymatic activity and synthetic inhibitors such as phenylthiourea significantly decreased it. The purified phenoloxidase has a molecular mass of 22kDa. The current paper represents a further step towards the characterization of humoral immunity of E. integriceps in order to develop new strategies for the biological control of the Sunn pest.
Department of Plant Protection, College of Agriculture, University of Guilan-Rasht, 41635-1314, Iran. arash.zibaee@gmx.com
Arash
A
Zibaee
Ali Reza
AR
Bandani
Davide
D
Malagoli
D000818:Animals; D004789:Enzyme Activation / Q000187:drug effects; D006430:Hemiptera / Q000201:enzymology*; D006434:Hemocytes / Q000201:enzymology*; D008970:Molecular Weight; D014442:Monophenol Monooxygenase / Q000037:antagonists & inhibitors / Q000302:isolation & purification* / Q000378:metabolism*; D010670:Phenylthiourea / Q000494:pharmacology; D013045:Species Specificity; D013329:Structure-Activity Relationship
D010670:Phenylthiourea; D014442:Monophenol Monooxygenase