Biosynthesis of Isoprenoid Membranes in the Methanogenic Archeabacterium Methanospirillum hungatei

Article abstract of DOI:10.1021/ja00216a041

The biosynthesis of 2,3-di-O-phytanyl-sn-glycerol (1) and 2,3-di-O-biphytanyl-sn-diglycerol (2), which are primary lipid components of the cell membrane of Methanospirillum hungatei, was studied by incorporation of 14C-labeled diether 1 and its monophosphate 1-P, 14C-labeled tetraether 2 and its monophosphate 2-P, <1-3H>phytanol (3), <1-3H>-(E)-phytol (4), and <1-3H>-(E,E,E)-geranylgeraniol (5).No interconversion was found between the di- and tetraethers.Geranylgeraniol (5) was readily in corporated into ethers 1 and 2; phytol (4) was incorporated poorly; and phytanol (3) was not incorporated.The results suggest that the ether linkages in archaebacterial lipids are established before the double bonds in the geranylgeranyl moiety are reduced and that diether 1 is not the immediate precursor of tetraether 2.