title: A trypsin-like protease in rice green semi-looper, Naranga aenescens Moore (Lepidoptera: Noctuidae): purification and characterization.
abstract: The rice green semi looper, Naranga aenescens Moore (Lepidoptera: Noctuidae) causes severe damage to rice fields in Eastern Asia and Middle East. We demonstrate that two types of serine proteases are active in the midgut of the third instar larvae of N. aenescens, but trypsin-like proteases are considerably more active than chymotrypsin-like proteases. To develop better control strategies, purification and biochemical characterization of a major trypsin-like digestive protease from the midgut of the third instar larvae of N. aenescens was achieved by gel filtration and anion exchange chromatography. After the final purification step, the enzyme was purified 9.62-fold with a recovery of 16.1% and a specific activity of 4.12 U/mg protein and a molecular mass of approximately 88.5 kDa. Biochemical characterization indicated that the purified protease had highest activity at pH 10 and 30°C and was stable for up to 6 h under those conditions. Divalent cations, especially Ca2+, Mg2+, and Cu2+, increased the enzyme activity and synthetic inhibitors that target trypsin-like activity caused a significant reduction in caseinolytic activity. These data may be used to develop inhibitors that decrease the damage of N. aenescens to rice cultivars in the field.
authors.affiliation: Department of Plant Protection, College of Agriculture, University of Guilan, Rasht, Iran. arash.zibaee@gmx.com.
authors.forename: Arash
authors.initials: A
authors.lastname: Zibaee
authors.forename: Ali Reza
authors.initials: AR
authors.lastname: Bandani
authors.forename: Mahmoud
authors.initials: M
authors.lastname: Fazeli-Dinan
authors.forename: Idin
authors.initials: I
authors.lastname: Zibaee
authors.forename: Jalal Jalali
authors.initials: JJ
authors.lastname: Sendi
authors.forename: Feizollah A
authors.initials: FA
authors.lastname: Maleki
mesh_terms: D000818:Animals; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D004064:Digestive System / Q000201:enzymology*; D006863:Hydrogen-Ion Concentration; D007814:Larva / Q000201:enzymology / Q000378:metabolism; D009036:Moths / Q000201:enzymology* / Q000378:metabolism; D011480:Protease Inhibitors / Q000494:pharmacology; D012697:Serine Endopeptidases / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism*; D013696:Temperature; D014357:Trypsin / Q000737:chemistry / Q000378:metabolism
chemical_list: D011480:Protease Inhibitors; D012697:Serine Endopeptidases; D014357:Trypsin