title: Iron-dependent superoxide dismutase from novel thermoacidophilic crenarchaeon Acidilobus saccharovorans: from gene to active enzyme.
abstract: A gene encoding superoxide dismutase was revealed in the genome of the thermoacidophilic crenarchaeon Acidilobus saccharovorans. A recombinant expression vector was constructed and transformed into E. coli cells. The novel recombinant superoxide dismutase was purified and characterized. The enzyme was shown to be an iron-dependent superoxide dismutase able to bind various bivalent metals in the active site. According to differential scanning calorimetric data, the denaturation temperature of the enzyme is 107.3°C. The maximal activity of the Fe(II) reconstituted enzyme defined by xanthine oxidase assay is 1700 U/mg protein. Study of the thermal stability of the superoxide dismutase samples with various metal contents by tryptophan fluorescence indicated that the thermal stability and activity of the enzyme directly depend on the nature of the reconstituted metal and the degree of saturation of binding sites.
authors.affiliation: Bach Institute of Biochemistry, Russian Academy of Sciences, Leninsky pr. 33, 119071 Moscow, Russia. elslutskaya@yandex.ru
authors.forename: E S
authors.initials: ES
authors.lastname: Slutskaya
authors.forename: E Yu
authors.initials: EY
authors.lastname: Bezsudnova
authors.forename: A V
authors.initials: AV
authors.lastname: Mardanov
authors.forename: I V
authors.initials: IV
authors.lastname: Safenkova
authors.forename: S Yu
authors.initials: SY
authors.lastname: Kleimenov
authors.forename: N A
authors.initials: NA
authors.lastname: Chebotareva
authors.forename: V M
authors.initials: VM
authors.lastname: Gumerov
authors.forename: N V
authors.initials: NV
authors.lastname: Ravin
authors.forename: K G
authors.initials: KG
authors.lastname: Skryabin
authors.forename: V O
authors.initials: VO
authors.lastname: Popov
mesh_terms: D000595:Amino Acid Sequence; D019615:Crenarchaeota / Q000201:enzymology*; D004789:Enzyme Activation; D004795:Enzyme Stability; D004926:Escherichia coli / Q000235:genetics; D045482:Hot Springs / Q000382:microbiology; D006863:Hydrogen-Ion Concentration; D055503:Protein Multimerization; D020836:Protein Structure, Quaternary; D013482:Superoxide Dismutase / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D013481:Superoxides / Q000378:metabolism; D013696:Temperature
chemical_list: D013481:Superoxides; D013482:Superoxide Dismutase