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(S)-p-Hydroxy-mandelonitrile lyase from Sorghum bicolor has been crystallized in three different forms using the hanging-drop vapor-diffusion technique. Crystal form I is obtained from 1.4 M (NH(4))(2)SO(4) in 100 mM Na-acetate, pH 4.6, and belongs to the orthorhombic space group P2(1)2(1)2(1). The
Plant beta-glucosidases display varying substrate specificities. The maize beta-glucosidase isozyme Glu1 (ZmGlu1) hydrolyzes a broad spectrum of substrates in addition to its natural substrate DIMBOA-Glc (2-O-beta-d-glucopyranosyl-4-hydroxy-7-methoxy-1,4-benzoxaxin-3-one), whereas the sorghum
The in vitro substrate specificity of UDP-glucose:p-hydroxymandelonitrile-O-glucosyltransferase from Sorghum bicolor (UGT85B1) was examined using a range of potential acceptor molecules, including cyanohydrins, terpenoids, phenolics, hexanol derivatives and plant hormones. Qualitative enzyme
The localization of three monooxygenase (hydroxylase) enzyme systems which occur in dark-grown seedlings of Sorghum bicolor has been studied. Cinnamic acid 4-hydroxylase (CAH) (trans-cinnamate 4-monooxygenase, EC 1.14.13.11), which has been increasingly utilized in plants as a marker for the
Spectral scanning was used to provide estimates of the leakage of the cyanogenic glucoside, dhurrin (p-hydroxy-[S]-mandelonitrile-beta-d-glucoside), and its metabolite, p-hydroxybenzaldehyde (p-HB), from young light-grown shoots of Atlas sorghum (Sorghum bicolor [L.] Moench) when these shoots were
Studies with purified mesophyll and epidermal protoplasts and bundle sheath strands have shown that the cyanogenic glucoside dhurrin (p-hydroxy-(S)-mandelonitrile-beta-d-glucoside) is localized in the epidermis of sorghum leaves whereas the enzymes involved in its degradation (dhurrin
Two beta-glucosidases exhibiting high specificity for the cyanogenic glucoside dhurrin have been purified to near homogeneity from seedlings of Sorghum bicolor. Dhurrinase 1 was isolated from shoots of seedlings grown in the dark. Dhurrinase 2 was isolated from the green shoots of young seedlings
The maize beta-glucosidase isozyme Glu1 hydrolyzes a broad spectrum of substrates in addition to its natural substrate DIMBOAGlc (2-O-beta-d-glucopyranosyl-4-hydroxy-7-methoxy-1,4-benzoxazin-3-on e), whereas the sorghum beta-glucosidase isozyme Dhr1 hydrolyzes exclusively its natural substrate
Plant beta-glucosidases play a crucial role in defense against pests. They cleave, with variable specificity, beta-glucosides to release toxic aglycone moieties. The Sorghum bicolor beta-glucosidase isoenzyme Dhr1 has a strict specificity for its natural substrate dhurrin
The tissue distributions of dhurrin [p-hydroxy-(S)-mandelonitrile-beta-d-glucoside] and of enzymes involved in its metabolism have been investigated in leaf blades of light-grown Sorghum bicolor seedlings. Enzymic digestion of these leaves using cellulase has enabled preparations of epidermal and
The final step in the biosynthesis of the cyanogenic glucoside dhurrin in Sorghum bicolor is the transformation of the labile cyanohydrin into a stable storage form by O-glucosylation of (S)-p-hydroxymandelonitrile at the cyanohydrin function. The