Practical synthesis of [3-(2H3)methyl]mevalonolactone and incorporation experiment of [3-(2H3)methyl]mevalonolactone and [13C]labeled acetate in the biosynthesis of isoprenoidal diether lipids of halophilic archaea

Article abstract of DOI:10.1246/bcsj.73.2513

The biosynthesis of the saturated isoprenoid portion of membrane lipids of the halophilic archaea Natrinema pallidum was investigated. At first, a practical method for the synthesis of [3-(²H₃)methyl]mevalonate was developed. Then, incorporation experiments of [3-(²H₃)methyl]mevalonate into the lipid core indicated that the isoprenoid portion was derived from mevalonate. However, a [2-¹³C]acetate-incorporation experiment revealed a significant difference in the degree of ¹³C enrichment between the expected position from the mevalonate pathway, the CH₂ groups (and at one terminal CH₃ group) and the CH₃ groups in the saturated isoprenoid chain. These results suggest that (1) the mevalonate pathway exists and is active, and (2) a part of acetoacetyl-CoA is not derived from an acetate in the biosynthesis of the isoprenoidal lipid-core of the archaebacterium.