antibiotic-1233a and mevastatin

Topics: Amino Acid Sequence; Animals; Cholesterol; Cloning, Molecular; Farnesyl-Diphosphate Farnesyltransferase; Fatty Acids, Unsaturated; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hydroxymethylglutaryl-CoA Synthase; Lactones; Lovastatin; Molecular Conformation; Molecular Sequence Data; Sterol O-Acyltransferase

A new screening method for specific inhibitors of mevalonate biosynthesis was established using Vero cells, an animal cell line. The cultures selected were those which inhibited the growth of Vero cells in the EAGLE's minimum essential medium supplemented with 2% calf serum (2% CS-MEM) but lacked inhibitory activity against the growth of cells in 2% CS-MEM supplemented with 1 mM mevalonate. By this screening method, inhibitors of the two enzymes involved in mevalonate biosynthesis, 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) synthase and HMG-CoA reductase, were selected from about 11,000 soil isolates. The beta-lactone 1233A, a fungal metabolite, was found to be the first naturally occurring compound which inhibits HMG-CoA synthase specifically and strongly. Monacolins K and J, inhibitors of HMG-CoA reductase, were also detected and identified.

Topics: Actinomycetales; Animals; Anti-Bacterial Agents; Cell Division; Fatty Acids, Unsaturated; Fungi; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hydroxymethylglutaryl-CoA Synthase; Lactones; Lovastatin; Mevalonic Acid; Molecular Structure; Naphthalenes; Oxo-Acid-Lyases; Soil Microbiology; Vero Cells

A beta-lactone isolated from Scopulariopsis sp. shows a potent inhibition of cholesterogenesis. The structure of this beta-lactone, termed F-244, is 3,5,7-trimethyl-12-hydroxy-13-hydroxymethyl-2,4-tetradecadiendioic acid 12,14-lactone. The inhibition site of F-244 in cholesterol synthesis was studied. The growth of Vero cells was inhibited at 6.25-12.5 micrograms/ml of F-244. The inhibition of growth was overcome by the addition of mevalonate to the culture medium, but not by the addition of acetate. In a rat liver enzyme system, the incorporations of [14C]acetate and [14C]acetyl-CoA into digitonin-precipitable sterol were 50% inhibited by 0.58 microgram/ml of F-244. The incorporation of [14C]mevalonate was not affected. Studies on the effects of F-244 on the three enzymes involved in mevalonate biosynthesis demonstrated that the drug specifically inhibits HMG-CoA synthase with IC50 value of 0.065 microgram/ml. The effect of analogs of F-244 on HMG-CoA synthase was also investigated.

Topics: Acetates; Acetic Acid; Acetyl Coenzyme A; Acetyl-CoA C-Acetyltransferase; Animals; Carbohydrate Sequence; Cell Line; Fatty Acids, Unsaturated; Hydroxymethylglutaryl-CoA Synthase; Lactones; Liver; Lovastatin; Mevalonic Acid; Oxo-Acid-Lyases; Rats; Sterols