Observation of the pathway from lysine to the isoprenoidal lipid of halophilic archaea, Halobacterium halobium and Natrinema pallidum, using regiospecifically deuterated lysine

We examined the incorporation of lysine into archaeal isoprenoidal lipids of halophilic archaea, Natrinema pallidum and Halobacterium halobium using two regiospecifically deuterium-labeled derivatives, [3,3-²H₂] and [6,6-²H₂]lysines. The two deuterated lysines were synthesized, and the incorporation of deuterium to the lipid core was defined by ²H NMR. The results revealed that lysine is degraded to crotonoyl-CoA by the decarboxylation of carboxylate in the metabolism of halophilic archaea, much like the metabolism of lysine in aerobic bacteria; the process converts lysine to isoprenoidal lipids via the mevalonate pathway through glutaryl-CoA, crotonoyl-CoA, and acetoacetyl-CoA.