The localization, partial purification and regulation of pea plastid HMG-CoA reductase

HMG-CoA reductase was located to the envelope membranes of pea etioplasts, the first report of the suborganelle localization of this key enzyme in isoprenoid synthesis. The enzyme was purified 156 fold from isolated envelope membranes. Purification was achieved by detergent solubilization, hydroxylapatite chromatography and glycerol gradient centrifugation. Membrane-bound etioplast HMG-CoA reductase was activated 4 to 5 fold by high concentrations of inorganic phosphate, this activation was prevented by arsenate, a structural analog of phosphate.