@article{motoyama_kao_lin_dauterman_1984, title={DUAL ROLE OF ESTERASES IN INSECTICIDE RESISTANCE IN THE GREEN RICE LEAFHOPPER}, volume={21}, ISSN={["0048-3575"]}, DOI={10.1016/0048-3575(84)90049-X}, abstractNote={The role of esterases as related to insecticide resistance was studied in an organophosphorus (OP)-resistant strain of the green rice leafhopper. As judged by p-nitrophenyl acetate hydrolysis, 21, 5, and 74% of the esterase activity was located in nuclei/mitochondria, microsomes, and the soluble fraction, respectively. All the fractions were active in hydrolyzing malathion, paraoxon, and fenvalerate. Hydrolysis of malathion and fenvalerate increased with time while that of paraoxon reached a plateau within 15 min. Since a considerable amount of p-nitrophenol was detected in the paraoxon reaction at 0°C and at zero time, the formation of p-nitrophenol may be due to phosphorylation of the esterases rather than phosphorotriesterase action. The results suggest a dual role for esterases in resistance mechanisms; a catalyst for hydrolysis of malathion and fenvalerate, and a binding protein for the oxygen analogs of other OP insecticides, both of which would protect the intrinsic target, acetylcholinesterase, from inhibition. Chromatofocusing of the soluble fraction resolved five esterase peaks, I–V. These esterases were active toward the three general substrates as well as for the three insecticides tested, except for Peak I in which the overall activity was too low. Thin-layer agar gel electrophoresis showed that the chromatofocusing peaks I–V corresponded to the electrophoretic bands E1–E5, some of which were previously shown to be associated with OP resistance. The dual role of these esterases may explain the cross-resistance between malathion and other OP insecticides as well as synergism between OP and carbamate insecticides.}, number={2}, journal={PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY}, author={MOTOYAMA, N and KAO, LR and LIN, PT and DAUTERMAN, WC}, year={1984}, pages={139–147} }
 @article{motoyama_kulkarni_hodgson_dauterman_1978, title={ENDOGENOUS INHIBITORS OF GLUTATHIONE S-TRANSFERASES IN HOUSE-FLIES}, volume={9}, ISSN={["0048-3575"]}, DOI={10.1016/0048-3575(78)90005-6}, abstractNote={The inhibition of glutathione S-transferase by endogenous compounds present in the soluble fraction of house fly homogenates was investigated. The highest inhibition was found with the female abdomen and increased with incubation time and with an increase in the tissue concentration. The correlation of increased inhibition with a parallel increase in the darkening of the soluble fraction indicated a possible association with melanization, thereby suggesting quinones as the possible endogenous inhibitiors of glutathione transferase. In vitro experiments demonstrated that quinones produced by mushroom tyrosinase did indeed inhibit glutathione S-transferase. Inhibition by quinones can be prevented by including glutathione or bovine serum albumin in the homogenization buffer. The inhibitory activity of a variety of quinones and related compounds on purified glutathione S-transferase was investigated. Oxygenated aromatics with hydroxy groups in the 1,2- or 1,4-position or ketonic carbonyls in the 1,4-position are good inhibitors of glutathione S-transferase.}, number={3}, journal={PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY}, author={MOTOYAMA, N and KULKARNI, AP and HODGSON, E and DAUTERMAN, WC}, year={1978}, pages={255–262} }
 @article{motoyama_dauterman_1978, title={MOLECULAR-WEIGHT, SUBUNITS, AND MULTIPLE FORMS OF GLUTATHIONE S-TRANSFERASE FROM HOUSE-FLY}, volume={8}, ISSN={["0020-1790"]}, DOI={10.1016/0020-1790(78)90019-7}, abstractNote={Glutathione S-transferase was purified 106 fold from an insecticide-resistant strain of the house fly. Polyacrylamide gel electrophoresis of the enzyme resolved multiple activity bands for 3,4-dichloronitrobenzene conjunction. Electrophoresis of the extracts of the individual bands suggested that they may be derived from the same enzyme. The molecular weight of the native enzyme and its primary dissociated form was estimated to be 54,000 and 37,000, respectively. The dissociated form showed a discontinuity at about 35 C in an Arrenhius plot, while the native enzyme exhibited a continuous line. SDS gel electrophoresis of the native enzyme and of the individual electrophoretic bands resulted in the separation of a predominant subunit with an approximate molecular weight of 22,700. Numerous minor bands with various molecular weights were also detected. It was suggested that the multiple forms of the house fly glutathione S-transferase observed in electrophoresis, or eluted from CM-cellulose columns, may be due to dissociation, aggregation, or binding with bromophenol blue which alters the molecular weight and the molecular charge of the enzyme.}, number={5}, journal={INSECT BIOCHEMISTRY}, author={MOTOYAMA, N and DAUTERMAN, WC}, year={1978}, pages={337–348} }
 @article{motoyama_dauterman_plapp_1977, title={GENETIC STUDIES ON GLUTATHIONE-DEPENDENT REACTIONS IN RESISTANT STRAINS OF HOUSE-FLY, MUSCA-DOMESTICA-L}, volume={7}, ISSN={["0048-3575"]}, DOI={10.1016/0048-3575(77)90005-0}, abstractNote={Genetic studies of glutathione-dependent reactions were conducted with a diazinon-resistant house fly strain in which resistance is controlled primarily by genes on chromsome II. The resistant strain was crossed with a susceptible strain which had mutant markers on chromosomes II, III, and V, and the F1 was backcrossed to the susceptible strain. Glutathione transferase activities of the resultant eight phenotypes were measured using 3,4-dichloronitrobenzene, methyl iodide, and γ-benzene hexachloride as substrates. High levels of all these activities are controlled by gene(s) on chromosome II. Further analysis was made by introducing diazinon resistance into a susceptible strain via genetic crossing-over. Intermediate activity levels for 3,4-dichloronitrobenzene and methyl iodide conjugations were introduced along with intermediate levels of resistance. Assays of individual flies of the synthesized strain revealed they were heterogeneous for glutathione-dependent activities, consisting of individuals with low, intermediate, and high transferase activity. Based on these results, high levels of the glutathione-dependent enzymes are not a major biochemical mechanism responsible for diazinon resistance. It was also demonstrated that glutathione S-aryltransferase and S-alkyltransferase in the house fly, as measured with 3,4-dichloronitrobenzene and methyl iodide, are inseparable genetically and may, therefore, be the same enzyme.}, number={5}, journal={PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY}, author={MOTOYAMA, N and DAUTERMAN, WC and PLAPP, FW}, year={1977}, pages={443–450} }
 @article{motoyama_dauterman_1977, title={PURIFICATION AND PROPERTIES OF HOUSEFLY GLUTATHIONE S-TRANSFERASE}, volume={7}, ISSN={["0020-1790"]}, DOI={10.1016/0020-1790(77)90039-7}, abstractNote={Glutathione S-transferases were partially purified from an insecticide resistant and a susceptible strain of houseflies and characterized using 3,4-dichloronitrobenzene (DCNB) as the substrate. The molecular weight of the enzyme was estimated to be 50,000 and SDS gel electrophoresis revealed that the enzyme consisted of two equal subunits of 23,000. An Arrhenius plot of temperature versus DCNB conjugation showed a discontinuity at about 35°C. The optimum pH for enzyme activity was 9.5 to 10. A difference in the equilibrium constants between the enzymes from the resistant and susceptible strains did not explain the higher overall reactions in the resistant strain. The same enzyme was active for methyl iodide conjugation, degradation of organophosphorus insecticides and γ-BHC, but was inactive for DDT-dehydrochlorination. The degradation of organophosphorus insecticides was via alkyl conjugation and/or “leaving group” conjugation.}, number={4}, journal={INSECT BIOCHEMISTRY}, author={MOTOYAMA, N and DAUTERMAN, WC}, year={1977}, pages={361–369} }
 @article{motoyama_dauterman_rock_1977, title={TOXICITY OF O-ALKYL ANALOGS OF AZINPHOSMETHYL AND OTHER INSECTICIDES TO RESISTANT AND SUSCEPTIBLE PREDACEOUS MITES, AMBLYSEIUS-FALLACIS (ACARINA-PHYTOSEIIDAE)}, volume={70}, ISSN={["0022-0493"]}, DOI={10.1093/jee/70.4.475}, abstractNote={Toxicities of O-alkyl analogues of azinphosmethyl were determined for a susceptible and an azinphosmethyl resistant strain of the predaceous mite, Amblyseius fallacis (Garman). The resistance factor, R/S , decreased with the ethyl and n -propyl analogues, verifying previous findings that the glutathione transferases were responsible for resistance in this strain of mite. Cross-resistance is possible to various organophosphate insecticides, particularly those with O-methyl groups.}, number={4}, journal={JOURNAL OF ECONOMIC ENTOMOLOGY}, author={MOTOYAMA, N and DAUTERMAN, WC and ROCK, GC}, year={1977}, pages={475–476} }
 @article{motoyama_dauterman_1975, title={INTERSTRAIN COMPARISON OF GLUTATHIONE-DEPENDENT REACTIONS IN SUSCEPTIBLE AND RESISTANT HOUSEFLIES}, volume={5}, ISSN={["0048-3575"]}, DOI={10.1016/0048-3575(75)90022-X}, abstractNote={Glutathione S-alkyl- and S-aryltransferase activities and the glutathione-dependent reactions involved in the metabolism of diazinon, parathion, DDT and γ-BHC were determined in two susceptible and three resistant housefly strains. The relative rate of formation of desethyl diazinon and desethyl parathion and the degradation of γ-BHC paralleled the activities of the alkyl and aryltransferases in the various strains of houseflies suggesting that a single enzyme might be involved. DDT-dehydrochlorinase showed different relative rates among the strains indicating that the dechlorination was catalyzed by a different enzyme. The enzyme responsible for the conjugation of the pyrimidinyl moiety of diazinon appears to be different from the one which catalyzes the conjugation of the p-nitrophenyl moiety of parathion. The dearylation reactions were not mediated by the glutathione S-aryltransferase in the various housefly strains.}, number={5}, journal={PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY}, author={MOTOYAMA, N and DAUTERMAN, WC}, year={1975}, pages={489–495} }
 @article{motoyama_dauterman_1974, title={ROLE OF NONOXIDATIVE METABOLISM IN ORGANOPHOSPHORUS RESISTANCE}, volume={22}, ISSN={["1520-5118"]}, DOI={10.1021/jf60193a055}, abstractNote={ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTRole of nonoxidative metabolism in organophosphorus resistanceNaoki. Motoyama and W. C. DautermanCite this: J. Agric. Food Chem. 1974, 22, 3, 350–356Publication Date (Print):May 1, 1974Publication History Published online1 May 2002Published inissue 1 May 1974https://doi.org/10.1021/jf60193a055RIGHTS & PERMISSIONSArticle Views69Altmetric-Citations52LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (849 KB) Get e-Alerts Get e-Alerts}, number={3}, journal={JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY}, author={MOTOYAMA, N and DAUTERMAN, WC}, year={1974}, pages={350–356} }
 @article{motoyama_rock_dauterman_1971, title={Studies on the mechanism of azinphosmethyl resistance in the predaceous mite, Neoseiulus (T.) fallacis (Family : Phytoseiidae)}, volume={1}, number={2}, journal={Pesticide Biochemistry and Physiology}, author={Motoyama, N. and Rock, G. C. and Dauterman, W. C.}, year={1971}, pages={205} }