Echinocystis lobata

Echinocystis ELTI-I Echinocystis lobata TRY (15pM), cathepsin G (79nM)... 

Glycine max, Ricinus communis, Echinocystis lobata, Psophocarpus tetragonolobus Arachis hypogaea, Crotalaria juncea, Ricinus communis, Momordica charantia... 

Cell-free systems that convert ABA to PA have been obtained from liquid endosperm of Echinocystis lobata [109] and ABA-induced maize suspension cells [110]. The 8 -OH-ABA intermediate could be trapped by freezing short-term incubation mixtures, followed by lyophilization and acetylation [109]. The hydroxylating activity is localized to the microsomal fraction, requires O2 and NADPH [109,110], and is inhibited by CO [109], indicating that ABA 8 -hydroxylase is a cytochrome P450 monooxygenase. This is... 

The metabolism of ABA to phaseic acid is initiated by hydroxylation at C-8 (Fig. 5). The enzyme catalyzing this reaction in Echinocystis lobata was found to be microsomal and to require O2 and NADPH [18]. Although it was not fully characterized, the enzyme has properties consistent with a monooxygenase which, as a methyl hydroxylase, is a potential site of action of the N-heterocyclics. There is evidence that this reaction may indeed be inhibited in some cases, leading to increased ABA levels [49] and therefore reduced transpiration [2]. Although there is little information on the structural requirements for inhibitors of ABA metabolism, it is of interest to note that inhibition of both this reaction and e/z kaurene oxidation would result in growth retardation. 

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