title: Type III Cu mutants of Myrothecium verrucaria bilirubin oxidase.
abstract: Type III Cu ligand, His456 and His458, of Myrothecium verrucaria (MT-1) bilirubin oxidases (BO) [EC 1.3.3.5] were doubly mutated as to Lys, Asp, and Val. In spite of perturbation of the type III Cu centers, these mutants were pale blue or colourless when isolated. However, they became intense blue on reaction with reducing agents such as dithionite, ascorbate, hexacyanoferrate(II), and octacyanotangstate(IV) under air, or with an oxidizing agent such as hexacyanoferrate(III), indicating that they are in mixed forms when expressed in Aspergillus oryzae. His456.458Lys and His456.458Asp mutated as to potential coordinating groups showed weak BO and ferroxidase activities, while His 456.458Val mutated as to non-coordinating groups showed no enzyme activity at all.
authors.affiliation: Department of Chemistry, Faculty of Science and Technology, Aoyama Gakuin University, Chitosedai, Setagaya, Tokyo 157-8572.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Shimizu
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Samejima
authors.forename: Shun
authors.initials: S
authors.lastname: Hirota
authors.forename: Shotaro
authors.initials: S
authors.lastname: Yamaguchi
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Sakurai
authors.forename: Takeshi
authors.initials: T
authors.lastname: Sakurai
mesh_terms: D000595:Amino Acid Sequence; D001203:Ascomycota / Q000201:enzymology* / Q000235:genetics; D001236:Aspergillus oryzae / Q000201:enzymology / Q000235:genetics; D002570:Ceruloplasmin / Q000187:drug effects / Q000378:metabolism; D003300:Copper / Q000737:chemistry*; D004578:Electron Spin Resonance Spectroscopy / Q000295:instrumentation / Q000379:methods; D006639:Histidine / Q000235:genetics; D006801:Humans; D008024:Ligands; D008969:Molecular Sequence Data; D009154:Mutation; D044925:Oxidoreductases Acting on CH-CH Group Donors / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
chemical_list: D008024:Ligands; D006639:Histidine; D003300:Copper; D002570:Ceruloplasmin; D044925:Oxidoreductases Acting on CH-CH Group Donors; C042401:bilirubin oxidase