title: Effect of catalase-specific inhibitor 3-amino-1,2,4-triazole on yeast peroxisomal catalase in vivo.
abstract: 3-Amino-1,2,4-triazole (3-AT) is known as an inhibitor of catalase to whose active center it specifically and covalently binds. Subcellular fractionation and immunoelectronmicroscopic observation of the yeast Candida tropicalis revealed that, in 3-AT-treated cells in which the 3-AT was added to the n-alkane medium from the beginning of cultivation, catalase transported into peroxisomes was inactivated and was present as insoluble aggregated forms in the organelle. The aggregation of catalase in peroxisomes occurred only in these 3-AT-treated cells and not in cells in which 3-AT was added at the late exponential growth phase. Furthermore, 3-AT did not affect the transportation of catalase into peroxisomes. The appearance of aggregation only in cells to which 3-AT was added from the beginning of cultivation suggests that, in the process of catalase transportation into yeast peroxisomes, some conformational change may take place and that correct folding may be inhibited by the binding of 3-AT to the active center of catalase. Accordingly, 3-AT will be an interesting compound for investigation of the transport machinery of the peroxisomal tetrameric catalase.
authors.affiliation: Laboratory of Applied Biological Chemistry, Department of Synthetic Chemistry, Graduate School of Engineering, Kyoto University, Yoshida, Sakyo-ku, 606-8501, Kyoto, Japan. miueda@sbchem.kyoto-u.ac.jp
authors.forename: Mitsuyoshi
authors.initials: M
authors.lastname: Ueda
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kinoshita
authors.forename: Tomoko
authors.initials: T
authors.lastname: Yoshida
authors.forename: Naomi
authors.initials: N
authors.lastname: Kamasawa
authors.forename: Masako
authors.initials: M
authors.lastname: Osumi
authors.forename: Atsuo
authors.initials: A
authors.lastname: Tanaka
mesh_terms: D000640:Amitrole / Q000494:pharmacology*; D041022:Candida tropicalis / Q000187:drug effects / Q000201:enzymology* / Q000254:growth & development; D002374:Catalase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D003470:Culture Media; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D016253:Microscopy, Immunoelectron; D020675:Peroxisomes / Q000187:drug effects / Q000201:enzymology*; D013347:Subcellular Fractions / Q000201:enzymology
chemical_list: D003470:Culture Media; D004791:Enzyme Inhibitors; D002374:Catalase; D000640:Amitrole