|
Titre :
|
Activity of phosphatases and esterases in the aphid, Acyrthosiphon pisum (Hemiptera: Sternorrhyncha: Aphididae), and in the gut wall of Galleria mellonella (Lepidoptera: Pyralidae) larvae and pupae
|
|
Auteurs :
|
V. Nemec ;
J. Zenka
|
|
Type de document :
|
article/chapitre/communication
|
|
Année de publication :
|
1996
|
|
Format :
|
37-44
|
|
Langues:
|
= Anglais
|
|
Mots-clés:
|
phosphatases
;
esterase
;
enzyme kinetics
;
zymogramme patterns
;
ecdysone titre
;
ecdysteroid mobilization
;
Acyrthosiphon pisum
;
Galleria mellonella
;
Hormone
;
Proteine
;
Metabolisme
;
Aphididae
;
Lepidoptera Pyralidae
|
|
Résumé :
|
The activity and isozyme patterns of esterases and phosphatases which hydrolyse ecdysteroid conjugates were studied in whole body extracts of Acyrthosiphon pisum (Harris) and in midgut wall extracts of Galleria mellonella (L.). The activity of esterases was almost ten times higher than that of phosphatases (expressed in mu M liberated para-nitrophenol/min/mg protein) and seemed to decline with insect age. Cholinesterase sensitive to eserin comprised 14% of total esterase activity in the nymphs of A. pisum, while in other samples it was negligible. Activity of acid phosphatases in the aphid samples was twice as high as that of alkaline phosphatases, while a reverse 3 : 1 ratio was found in the wax moth. The alkaline phosphatases revealed higher sensitivity to fluoride than the acid phosphatases. Esterases were more variable in their isozyme patterns during development than the phosphatases. A possible mechanism of ecdysteroid mobilization from their conjugates and the role of hydrolyzing enzymes in these processes is discussed.
|
|
Source :
|
European Journal of Entomology - 1210-5759, vol. 93, n° 1
|
