title: Evidence for the essential histidine residues in geranylgeranyl transferase type I from bovine testis.
abstract: Geranylgeranyl transferase was purified 30,000-fold by sequential use of 30-50% ammonium sulfate fractionation, Q-Sepharose anion exchange chromatography, Phenyl Superose hydrophobic interaction chromatography, Sephacryl S-300 gel filtration chromatography, and peptide (YREKKFFCAIL) affinity chromatography. Geranylgeranyl transferase, when incubated with diethyl pyrocarbonate (DEPC), a histidine-specific reagent, shows time-dependent inactivation, and the activity is restored by the addition of neutral hydroxylamine. The inactivation follows pseudo-first order kinetics with a second order rate constant of 0.319 M-1min-1. The overall results thus provide evidence that a histidine residue in the active site is involved in the catalytic mechanism of the geranylgeranyl transferase reaction.
authors.affiliation: Department of Chemistry, College of Natural Sciences, Seoul National University, Korea.
authors.forename: H
authors.initials: H
authors.lastname: Kim
authors.forename: B Y
authors.initials: BY
authors.lastname: Yoon
authors.forename: C H
authors.initials: CH
authors.lastname: Yang
mesh_terms: D019883:Alkyl and Aryl Transferases / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000302:isolation & purification; D000818:Animals; D001665:Binding Sites; D002417:Cattle; D002845:Chromatography; D004047:Diethyl Pyrocarbonate / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006639:Histidine / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D019811:Hydroxylamine / Q000494:pharmacology; D007461:Iodoacetates / Q000494:pharmacology; D019807:Iodoacetic Acid; D007700:Kinetics; D008297:Male; D013737:Testis / Q000201:enzymology*
chemical_list: D004791:Enzyme Inhibitors; D007461:Iodoacetates; D019811:Hydroxylamine; D006639:Histidine; D019883:Alkyl and Aryl Transferases; C083291:geranylgeranyltransferase type-I; D004047:Diethyl Pyrocarbonate; D019807:Iodoacetic Acid