title: Enzymatic formation of dehydrodolichal and dolichal, new products related to yeast dolichol biosynthesis.
abstract: Two new polyprenyl products in addition to dehydrodolichol and dolichol were detected by two-plate silica gel thin layer chromatography of nonpolar products formed from [1-14C]isopentenyl diphosphate and farnesyl diphosphate in the reaction with a crude 1,000 x g supernatant of yeast homogenates in the presence of NADPH. The new products were indistinguishable from authentic dehydrodolichal and dolichal. Analyses of the time-dependent and pH-dependent formation of the four products including dehydrodolichal and dolichal suggested that the biosynthetic pathway from dehydrodolichol leading to dolichal is different from that to dolichol. In double-labeled experiments with a combination of -l-14C-isopentenyl diphosphate and a [4B-3H]NADPH-generating system, the ratio of 3H- and 14C-derived radioactivities found in dolichal was six times higher than that in dolichol. A small amount of 3H-labeled dehydrodolichol was also detected. Considering the fact that dolichol is synthesized from dehydrodolichol (Sagami, H., Kurisaki, A., and Ogura, K. (1993) J. Biol. Chem. 268, 10109-10113), we propose that dehydrodolichol is a common branch point intermediate in the biosynthetic pathways leading to dolichal and dolichol and that dehydrodolichal is an intermediate in the pathway from dehydrodolichol to dolichal.
authors.affiliation: Institute for Chemical Reaction Science, Tohoku University, Katahira, Sendai, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Sagami
authors.forename: Y
authors.initials: Y
authors.lastname: Igarashi
authors.forename: S
authors.initials: S
authors.lastname: Tateyama
authors.forename: K
authors.initials: K
authors.lastname: Ogura
authors.forename: J
authors.initials: J
authors.lastname: Roos
authors.forename: W J
authors.initials: WJ
authors.lastname: Lennarz
mesh_terms: D002250:Carbon Radioisotopes; D002855:Chromatography, Thin Layer; D003902:Detergents / Q000494:pharmacology; D004286:Dolichols / Q000031:analogs & derivatives* / Q000302:isolation & purification / Q000378:metabolism*; D045782:Hemiterpenes; D007700:Kinetics; D009249:NADP / Q000378:metabolism; D009943:Organophosphorus Compounds / Q000378:metabolism*; D011865:Radioisotope Dilution Technique; D012441:Saccharomyces cerevisiae / Q000254:growth & development / Q000378:metabolism*; D014316:Tritium
chemical_list: D002250:Carbon Radioisotopes; D003902:Detergents; D004286:Dolichols; D045782:Hemiterpenes; D009943:Organophosphorus Compounds; C099276:dehydrodolichal; C099275:dolichal; D014316:Tritium; C004809:isopentenyl pyrophosphate; D009249:NADP