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Characterization Of General Esterases From Susceptible And Parathion-Resistant Strains Of The Greenbug (Homoptera: Aphididae), Midori Ono, Jonathan S. Richman, Blair Siegfried
Characterization Of General Esterases From Susceptible And Parathion-Resistant Strains Of The Greenbug (Homoptera: Aphididae), Midori Ono, Jonathan S. Richman, Blair Siegfried
Department of Entomology: Faculty Publications
A susceptible and two parathion-resistant strains of the greenbug, Schizaphis graminum (Rondani), exhibit three different patterns of general esterase isozymes in native polyacrylamide electrophoresis gels. Characterization of general esterase activity using α -naphtholic esters as model substrates indicated that the three strains differed in isozyme composition. The type-I1 strain, which had the highest level of resistance, exhibited the highest levels of general esterase activity under all assay conditions, and the type-I strain had consistently higher levels than the susceptible strain. In all three strains, these esterases were more active toward α -naphtholic esters with side chains of six or fewer …
Subcellular Distribution And Characterization Of Esterase Isozymes From Insecticide-Resistant And -Susceptible Strains Of German Cockroach (Dictyoptera: Blatlellidae), Suresh K. Prabhakaran, Shripat T. Kamble
Subcellular Distribution And Characterization Of Esterase Isozymes From Insecticide-Resistant And -Susceptible Strains Of German Cockroach (Dictyoptera: Blatlellidae), Suresh K. Prabhakaran, Shripat T. Kamble
Department of Entomology: Faculty Publications
Esterases from insecticide-resistant and -susceptible strains of German cockroach, Blattella germanica (L.), were isolated and analyzed for differences in activity. The isozymes E5, E6, E7, and E8 of resistant strains indicated about two- to fivefold increases in activity compared with those of the susceptible strain. These isozymes constituted ≈60% of the total activity in the resistant strains, whereas they contributed only about 40% activity in the susceptible strain. Subcellular distribution studies showed that most esterase activity is present in the 100,000 x g fraction of the homogenate (cytosolic). Only a small portion of activity was membrane bound. Molecular weights of …