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Characterisation of aphid myrosinase and degradation studies of glucosinolates.
- Source :
-
Archives of insect biochemistry and physiology [Arch Insect Biochem Physiol] 2002 Aug; Vol. 50 (4), pp. 173-82. - Publication Year :
- 2002
-
Abstract
- Myrosinase from Brevicoryne brassicae was purified by ammonium sulfate fractionation, dialysis, and chromatography on a DEAE column. The chromatography yielded a single peak and a 115.6-fold purification. Further FPLC gel filtration gave a single peak at 120 kDa. Denaturing SDS/PAGE of the protein revealed a single band at 60 kDa, indicating that the native B. brassicae myrosinase is a dimer. Kinetic parameters towards 8 glucosinolates were calculated. Strong differences of V(max) and K(m) were observed depending on the substrate. Degradation products of each glucosinolate were identified and quantified by GC-MS and GLC-FID, respectively. Using both crude aphid homogenates and purified myrosinase, two unique hydroxyglucosinolates, 3-butenyl- and benzyl-isothiocyanates were identified from progoitrin ((2S)-2-hydroxybut-3-enyl-glucosinolate) and sinalbin (4-hydroxybenzyl-glucosinolate) degradation respectively. Addition of ascorbic acid to the reaction mixtures containing sinalbin and progoitrin caused the production of hydroxylated degradation products usually associated with plant myrosinase metabolisation. The occurrence of the myrosinase system in B. brassicae is discussed in terms of similar allelochemical adaptation between the herbivore and its host plant.<br /> (Copyright 2002 Wiley-Liss, Inc.)
- Subjects :
- Animals
Aphids growth & development
Biodegradation, Environmental
Chromatography, DEAE-Cellulose methods
Chromatography, Gel
Electrophoresis, Polyacrylamide Gel methods
Hydrolysis
Kinetics
Metalloendopeptidases isolation & purification
Substrate Specificity
Aphids enzymology
Glucosinolates pharmacokinetics
Metalloendopeptidases metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 0739-4462
- Volume :
- 50
- Issue :
- 4
- Database :
- MEDLINE
- Journal :
- Archives of insect biochemistry and physiology
- Publication Type :
- Academic Journal
- Accession number :
- 12125058
- Full Text :
- https://doi.org/10.1002/arch.10042