title: Geranylgeranyl diphosphate synthase catalyzing the single condensation between isopentenyl diphosphate and farnesyl diphosphate.
abstract: Geranylgeranyl diphosphate synthase was purified 191-fold from bovine brain by Mono Q column chromatography followed by preparative isoelectric focusing electrophoresis and Superose 12 gel filtration. The synthase had a pI value at 6.0, and it was made free of farnesyl diphosphate synthase, the pI of which was 5.1. The partially purified enzyme catalyzed the formation of geranylgeranyl diphosphate from isopentenyl diphosphate and farnesyl diphosphate with the Km values for isopentenyl diphosphate and farnesyl diphosphate being 14 and 0.8 microM, respectively. Dimethylallyl diphosphate and geranyl diphosphate were poor substrates with velocities of only 0.003 and 0.03, respectively, relative to that of farnesyl diphosphate. These results indicate that geranylgeranyl diphosphate synthase catalyzes a single condensation between isopentenyl diphosphate and farnesyl diphosphate and that farnesyl diphosphate is the common intermediate at the branch point for the synthesis of geranylgeranylated proteins as well as cholesterol, ubiquinone, dolichol, and farnesylated proteins. The enzyme required Mg2+ or Mn2+ for maximum activity. Octylglucoside showed a stimulatory effect on the enzyme activity.
authors.affiliation: Institute of Chemical Reaction Science, Tohoku University, Sendai.
authors.forename: H
authors.initials: H
authors.lastname: Sagami
authors.forename: T
authors.initials: T
authors.lastname: Korenaga
authors.forename: K
authors.initials: K
authors.lastname: Ogura
mesh_terms: D019883:Alkyl and Aryl Transferases; D000818:Animals; D001921:Brain / Q000201:enzymology*; D002417:Cattle; D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D051231:Farnesyltranstransferase; D045782:Hemiterpenes; D007525:Isoelectric Focusing; D007700:Kinetics; D008274:Magnesium / Q000494:pharmacology; D008345:Manganese / Q000494:pharmacology; D009943:Organophosphorus Compounds / Q000378:metabolism*; D011106:Polyisoprenyl Phosphates / Q000378:metabolism*; D012717:Sesquiterpenes; D013379:Substrate Specificity; D014166:Transferases / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D045782:Hemiterpenes; D009943:Organophosphorus Compounds; D011106:Polyisoprenyl Phosphates; D012717:Sesquiterpenes; C004809:isopentenyl pyrophosphate; D008345:Manganese; C004808:farnesyl pyrophosphate; D014166:Transferases; D019883:Alkyl and Aryl Transferases; D051231:Farnesyltranstransferase; D008274:Magnesium