ISSN:
1432-072X
Keywords:
Metabolism
;
Pterocarpan
;
Phytoalexins
;
Ascochyta rabiei
;
Monooxygenase
;
Flavoprotein
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Crude protein extracts from the chickpea (Cicer arietinum) pathogenic fungus Ascochyta rabiei catalyze the hydroxylation of the pterocarpan phytoalexins medicarpin and maackiain to the corresponding 1a-hydroxy-1,4-diene-3-one derivatives. The enzyme reaction depends on NAD(P)H and molecular oxygen. Low amounts of FAD are necessary for maximal enzyme activity. The pterocarpan hydroxylase is a new flavoprotein monooxygenase with a molecular weight of 58 kDa in SDS-PAGE. The soluble enzyme can utilize NADH and NADPH with similar values for K m and V max respectively. The pterocarpan hydroxylase and a pterocarpan reductase (M r 29 kDa; Höhl and Barz 1987) are constitutively expressed by A. rabiei isolates.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00243455
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