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Identification of a high‐affinity binding site for dinotefuran in the nerve cord of the American cockroach
Author(s) -
Miyagi Satoshi,
Komaki Iori,
Ozoe Yoshihisa
Publication year - 2006
Publication title -
pest management science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.296
H-Index - 125
eISSN - 1526-4998
pISSN - 1526-498X
DOI - 10.1002/ps.1156
Subject(s) - epibatidine , american cockroach , cockroach , nicotinic agonist , binding site , imidacloprid , neonicotinoid , acetylcholine receptor , biology , piperonyl butoxide , pharmacology , toxicology , chemistry , biochemistry , receptor , periplaneta , nicotinic acetylcholine receptor , pesticide , ecology , agronomy
The binding of the neonicotinoid insecticide dinotefuran to insect nicotinic acetylcholine receptors (nAChRs) was examined by a centrifugation method using the nerve cord membranes of American cockroaches and [ 3 H]dinotefuran (78 Ci mmol −1 ). The K d and B max values of [ 3 H]dinotefuran binding were estimated to be 13.7 n M and 14.8 fmol 40 µg −1 protein respectively by Scatchard analysis. Epibatidine, an nAChR agonist, showed a rather lower affinity to the dinotefuran binding site (IC 50 = 991 n M ) than dinotefuran (IC 50 = 5.02 n M ). Imidacloprid and nereistoxin displayed lower potencies than dinotefuran but higher potencies than epibatidine. The potencies of five dinotefuran analogues in inhibiting the specific binding of [ 3 H]dinotefuran to nerve cord membranes were determined. A good correlation ( r 2 = 0.970) was observed between the −log IC 50 values of the tested compounds and their piperonyl butoxide‐synergised insecticidal activities (−log LD 50 values) against German cockroaches. The results indicate that a high‐affinity binding site for dinotefuran is present in the nerve cord of the American cockroach and that the binding of ligands to the site leads to the manifestation of insecticidal activity. Copyright © 2006 Society of Chemical Industry