TY - JOUR
T1 - Partial purification and characterization of a methyl-parathion resistance-associated general esterase in Diabrotica virgifera virgifera (Coleoptera: Chrysomelidae)
AU - Zhou, Xuguo
AU - Scharf, Michael E.
AU - Sarath, Gautam
AU - Meinke, Lance J.
AU - Chandler, Laurence D.
AU - Siegfried, Blair D.
PY - 2004/2
Y1 - 2004/2
N2 - Increased hydrolytic metabolism of organophosphate insecticides has been associated with resistance among Nebraska western corn rootworm populations. In this study, resistance-associated esterases were partially purified by differential centrifugation, ion exchange, and hydroxyapatite column chromatography, with a final purification factor of 100-fold and recovery of approximately 10%. Kinetic analysis of the partially purified enzyme indicated that the Km of the group II esterases was identical for the two populations, although Vmax was consistently threefold higher in the resistant population. A putative esterase, DvvII, was further purified to homogeneity by preparative polyacrylamide gel electrophoresis. DvvII is a monomer with a molecular weight of approximately 66kDa, although three distinct isoforms with similar pIs were evident based on isoelectric focusing gel electrophoresis. Immunoassays with the Myzus persicae E4 antiserum indicated that group II esterases from D. v. virgifera were cross-reactive and expressed at much higher titers in the resistant population relative to the susceptible counterpart. These results suggest that the resistance is likely associated with overproduction of an esterase isozyme in resistant D. v. virgifera populations.
AB - Increased hydrolytic metabolism of organophosphate insecticides has been associated with resistance among Nebraska western corn rootworm populations. In this study, resistance-associated esterases were partially purified by differential centrifugation, ion exchange, and hydroxyapatite column chromatography, with a final purification factor of 100-fold and recovery of approximately 10%. Kinetic analysis of the partially purified enzyme indicated that the Km of the group II esterases was identical for the two populations, although Vmax was consistently threefold higher in the resistant population. A putative esterase, DvvII, was further purified to homogeneity by preparative polyacrylamide gel electrophoresis. DvvII is a monomer with a molecular weight of approximately 66kDa, although three distinct isoforms with similar pIs were evident based on isoelectric focusing gel electrophoresis. Immunoassays with the Myzus persicae E4 antiserum indicated that group II esterases from D. v. virgifera were cross-reactive and expressed at much higher titers in the resistant population relative to the susceptible counterpart. These results suggest that the resistance is likely associated with overproduction of an esterase isozyme in resistant D. v. virgifera populations.
KW - Characterization
KW - Diabrotica virgifera virgifera
KW - Esterase
KW - Insecticide resistance
KW - Purification
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U2 - 10.1016/j.pestbp.2003.10.003
DO - 10.1016/j.pestbp.2003.10.003
M3 - Article
AN - SCOPUS:3042686950
SN - 0048-3575
VL - 78
SP - 114
EP - 125
JO - Pesticide Biochemistry and Physiology
JF - Pesticide Biochemistry and Physiology
IS - 2
ER -