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פותח על ידי קלירמאש פתרונות בע"מ -
Properties and toxicological significance of diflubenzuron hydrolase activity in Spodoptera littoralis larvae
Year:
1988
Authors :
ישעיה, יצחק
;
.
Volume :
32
Co-Authors:
Ishaaya, I., Department of Entomology, ARO, The Volcani Center, Bet Dagan 50-250, Israel
Degheele, D., Faculty of Agricultural Sciences, State University of Ghent, Coupure Links 653, B-9000 Ghent, Belgium
Facilitators :
From page:
180
To page:
187
(
Total pages:
8
)
Abstract:
Optimal assay conditions for gut diflubenzuron (DFB) hydrolase(s) of the Egyptian cotton leaf worm Spodoptera littoralis larvae are 0.9 mg protein of the postmitochondrial supernatant fraction incubated for 2 hr at 37°C with 0.5 nmol [14C]DFB (uniformally labeled on the aniline ring) in 0.4 ml of 0.05 M glycine-NaOH buffer (pH 9.0). The radiolabeled metabolites are separated and quantitatively evaluated using a TLC procedure. DFB hydrolase activity is a major factor for DFB detoxification in S. littoralis larvae. This conclusion is based on the ability of the larval gut enzyme to hydrolyze DFB to 4-chloroaniline (4-CA) and 4-chlorophenylurea (4-CPU), 4-CA being a major metabolite with a level of about 10% and 4-CPU a minor one with a level of about 1% of the total recovery. A relatively high level of radiolabeled polar metabolites is observed at the origin of the TLC plate; these metabolites are considered to be conjugated materials. DFB hydrolysis is totally inhibited in vitro at a concentration of 10-5 M of profenofos or DEF, which are both considered typical esterase inhibitors. Over 90% inhibition of DFB hydrolase activity in vivo is obtained when larvae are fed with castor bean leaves treated with 2.4 × 10-4% profenofos. Addition of sublethal concentrations of profenofos to dietary DFB resulted in a considerably higher toxicity of the latter. © 1988.
Note:
Related Files :
animal experiment
diflubenzuron
hydrolase
intestine
invertebrate
nonhuman
radioisotope
Spodoptera littoralis
עוד תגיות
תוכן קשור
More details
DOI :
10.1016/0048-3575(88)90011-9
Article number:
Affiliations:
Database:
סקופוס
Publication Type:
מאמר
;
.
Language:
אנגלית
Editors' remarks:
ID:
28954
Last updated date:
02/03/2022 17:27
Creation date:
17/04/2018 00:43
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Scientific Publication
Properties and toxicological significance of diflubenzuron hydrolase activity in Spodoptera littoralis larvae
32
Ishaaya, I., Department of Entomology, ARO, The Volcani Center, Bet Dagan 50-250, Israel
Degheele, D., Faculty of Agricultural Sciences, State University of Ghent, Coupure Links 653, B-9000 Ghent, Belgium
Properties and toxicological significance of diflubenzuron hydrolase activity in Spodoptera littoralis larvae
Optimal assay conditions for gut diflubenzuron (DFB) hydrolase(s) of the Egyptian cotton leaf worm Spodoptera littoralis larvae are 0.9 mg protein of the postmitochondrial supernatant fraction incubated for 2 hr at 37°C with 0.5 nmol [14C]DFB (uniformally labeled on the aniline ring) in 0.4 ml of 0.05 M glycine-NaOH buffer (pH 9.0). The radiolabeled metabolites are separated and quantitatively evaluated using a TLC procedure. DFB hydrolase activity is a major factor for DFB detoxification in S. littoralis larvae. This conclusion is based on the ability of the larval gut enzyme to hydrolyze DFB to 4-chloroaniline (4-CA) and 4-chlorophenylurea (4-CPU), 4-CA being a major metabolite with a level of about 10% and 4-CPU a minor one with a level of about 1% of the total recovery. A relatively high level of radiolabeled polar metabolites is observed at the origin of the TLC plate; these metabolites are considered to be conjugated materials. DFB hydrolysis is totally inhibited in vitro at a concentration of 10-5 M of profenofos or DEF, which are both considered typical esterase inhibitors. Over 90% inhibition of DFB hydrolase activity in vivo is obtained when larvae are fed with castor bean leaves treated with 2.4 × 10-4% profenofos. Addition of sublethal concentrations of profenofos to dietary DFB resulted in a considerably higher toxicity of the latter. © 1988.
Scientific Publication
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