Mechanism of the inhibition of cholesterol biosynthesis by 6-fluoromevalonate.

J F Nave, H d'Orchymont, J B Ducep, F Piriou, M J Jung

Index: Biochem. J. 227(1) , 247-54, (1985)

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Abstract

6-Fluoromevalonate blocks the incorporation of mevalonic acid, but not that of isopentenyl pyrophosphate, into non-saponifiable lipids in a rat liver multienzyme system. With 3H-labelled 6-fluoromevalonate, it was found that 6-fluoromevalonate is converted to its phospho and pyrophospho derivatives in this system. The kinetics of the two kinases were studied. 6-Fluoromevalonate 5-pyrophosphate is a potent competitive inhibitor of pyrophosphomevalonate decarboxylase (Ki 37 nM). In the multienzyme assay for cholesterol biosynthesis, there is accumulation of mevalonate 5-phosphate and mevalonate 5-pyrophosphate in the presence of 5 microM-6-fluoromevalonate, and 6-fluoromevalonate 5-pyrophosphate is more effective than 6-fluoromevalonate in inhibiting cholesterol biosynthesis. We suggest therefore that 6-fluoromevalonate blocks cholesterol biosynthesis at the level of pyrophosphomevalonate decarboxylase after being pyrophosphorylated.