title: Thermal dissociation and conformational lock of superoxide dismutase.
abstract: The kinetics of thermal dissociation of superoxide dismutase (SOD) was studied in 0.05 M Tris-HCl buffer at pH 7.4 containing 10(-4) M EDTA. The number of conformational locks and contact areas and amino acid residues of dimers of SOD were obtained by kinetic analysis and biochemical calculation. The cleavage bonds between dimers of SOD during thermal dissociation and type of interactions between specific amino acid residues were also simulated. Two identical contact areas between two subunits were identified. Cleavage of these contact areas resulted in dissociation of the subunits, with destruction of the active centers, and thus, lost of activity. It is suggested that the contact areas interact with active centers by conformational changes involving secondary structural elements.
authors.affiliation: Institute of Biochemistry and Biophysics, University of Tehran, Iran.
authors.forename: J
authors.initials: J
authors.lastname: Hong
authors.forename: A A
authors.initials: AA
authors.lastname: Moosavi-Movahedi
authors.forename: H
authors.initials: H
authors.lastname: Ghourchian
authors.forename: M
authors.initials: M
authors.lastname: Amani
authors.forename: M
authors.initials: M
authors.lastname: Amanlou
authors.forename: F C
authors.initials: FC
authors.lastname: Chilaka
mesh_terms: D000818:Animals; D001665:Binding Sites; D002417:Cattle; D019281:Dimerization; D004795:Enzyme Stability; D008958:Models, Molecular; D011487:Protein Conformation; D021122:Protein Subunits / Q000737:chemistry / Q000378:metabolism; D013482:Superoxide Dismutase / Q000737:chemistry* / Q000378:metabolism; D013696:Temperature
chemical_list: D021122:Protein Subunits; D013482:Superoxide Dismutase