Regulation of Terpenoid Biosynthesis in Tapped Latex
The tapped latex of Euphorbia lathyris can convert acetate to several structurally different triterpenols (TOH) and their fatty acid esters (TE) (1). Simple low speed centrifugation of the latex affords a pellet that utilizes mevalonic acid as a triterpenoid precursor (2). Biosynthetic activity in the latex pellet is absolutely dependent upon the presence of an osmoticum (0.4 M sorbitol), indicating that biosynthesis occurs in an osmotically sensitive organelle. Calcium constitutes about 7.5% of dry latex weight, and the addition of Ca2+ to an EGTA-treated latex pellet stimulates triterpene biosynthesis. This study was undertaken to investigate whether the calcium binding protein, calmodulin, mediates Ca2+ effects upon triterpenoid biosynthesis.
KeywordsFatty Acid Ester Calcium Binding Protein Mevalonic Acid Bovine Heart Phosphodiesterase Activity
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