title: Purification of active recombinant trypanosome alternative oxidase.
abstract: Trypanosome alternative oxidase (TAO) is the terminal oxidase of the respiratory chain in long slender bloodstream forms of African trypanosomes. TAO is a cytochrome-independent, cyanide-insensitive quinol oxidase. These characteristics are distinct from those of the bacterial quinol oxidases, proteins that belong to the heme-copper terminal oxidase superfamily. The inability to purify stable TAO has severely hampered biochemical studies of the alternative oxidase family. In the present study, we were able to purify recombinant TAO to homogeneity from Escherichia coli membranes using the detergent digitonin. Kinetic analysis of the purified TAO revealed that the specific inhibitor ascofuranone is a competitive inhibitor of ubiquinol oxidase activity.
authors.affiliation: Department of Biomedical Chemistry, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Coichi
authors.initials: C
authors.lastname: Nihei
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Fukai
authors.forename: Keisuke
authors.initials: K
authors.lastname: Kawai
authors.forename: Arihiro
authors.initials: A
authors.lastname: Osanai
authors.forename: Yoshisada
authors.initials: Y
authors.lastname: Yabu
authors.forename: Takashi
authors.initials: T
authors.lastname: Suzuki
authors.forename: Nobuo
authors.initials: N
authors.lastname: Ohta
authors.forename: Nobuko
authors.initials: N
authors.lastname: Minagawa
authors.forename: Kazuo
authors.initials: K
authors.lastname: Nagai
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Kita
mesh_terms: D000818:Animals; D004591:Electrophoresis, Polyacrylamide Gel; D004791:Enzyme Inhibitors / Q000494:pharmacology; D024101:Mitochondrial Proteins; D010088:Oxidoreductases / Q000037:antagonists & inhibitors / Q000302:isolation & purification*; D010940:Plant Proteins; D011994:Recombinant Proteins / Q000037:antagonists & inhibitors / Q000302:isolation & purification; D012717:Sesquiterpenes / Q000494:pharmacology; D014345:Trypanosoma / Q000201:enzymology*; D000099188:Alternative Oxidase
chemical_list: D004791:Enzyme Inhibitors; D024101:Mitochondrial Proteins; D010088:Oxidoreductases; D010940:Plant Proteins; D011994:Recombinant Proteins; D012717:Sesquiterpenes; D000099188:Alternative Oxidase; C006640:ascofuranone