Abstract
During the biosynthesis from 2-14C-mevalonic acid to phytoene, with the cell-free extract of phytoene accumulating mutant of Staphylococcus, a phosphorylated intermediate (isopentenylpyrophosphate) is separated and identified.
The incubation mixture for this reaction contained 2-14C-mevalonic acid, Mg++, ATP, KF, 10-5M of iodoacetamide and partially purified enzyme. The ratio of 14C to 32P was 1 to 2 when AT32P was used as a cofactor. After the liberation of phosphate radicals with snake venom, liberated alcohol from the purified new substance was identified as isopentenol by the 3, 5-dinitrobenzoate derivative, and it was confirmed that the new substance was isopentenylpyrophosphate.
14C-isopentenol was degraded with ozone, and after steam-distillation, formaldehyde-dimedone derivative was separated. It contained radioactivity and it was, therefore, concluded that methylene carbon of isopentenol is derived from carbon No. 2 position of mevalonate.
The efficient conversion of Isopentenylpyrophosphate into phytoene is also confirmed.
