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.
我们研究了赖
氨酸在嗜盐古菌Natrinema pallidum和Halobacterium halobium的古菌异
戊烯醇类脂质中的掺入情况,使用了两种位点特异性
氘标记的衍
生物,[3,3-2H2]和[6,6-2H2]赖
氨酸。两种
氘标记赖
氨酸被合成,脂质核心的
氘掺入情况通过2H NMR确定。结果显示,赖
氨酸在嗜盐古菌代谢中通过
羧酸盐的脱羧作用降解为
丁烯酰
辅酶A,这与需氧细菌中赖
氨酸代谢类似;该过程通过戊二酰
辅酶A、
丁烯酰
辅酶A和乙酰
乙酰辅酶A途径将赖
氨酸转化为古菌异
戊烯醇类脂质。