Subcellular distribution and characterization of esterase isozymes from insecticide-resistant and -susceptible strains of German cockroach (Dictyoptera: Blattellidae).
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 approximately 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 the esterase isozymes calculated based on their retardation coefficients ranged between 48 and 81 kd.
Department of Entomology and Environment Programs, University of Nebraska, Lincoln 68583-0816.
S K
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Prabhakaran
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Kamble
D000818:Animals; D003058:Cockroaches / Q000201:enzymology* / Q000648:ultrastructure; D004950:Esterases / Q000032:analysis / Q000378:metabolism*; D007305:Insecticide Resistance; D007306:Insecticides; D007527:Isoenzymes / Q000032:analysis / Q000378:metabolism*; D008970:Molecular Weight; D013347:Subcellular Fractions / Q000201:enzymology*
D007306:Insecticides; D007527:Isoenzymes; D004950:Esterases