Click here to close
Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly.
We suggest using a current version of Chrome,
FireFox, or Safari.
Identification of the residues responsible for the alkaline inhibition of Cu,Zn superoxide dismutase: a site-directed mutagenesis approach.
Polticelli F
,
Battistoni A
,
O'Neill P
,
Rotilio G
,
Desideri A
.
???displayArticle.abstract???
The catalytic rate of wild type, two single (Lys 120-->Leu, Lys 134-->Thr), and one double (Lys 120-->Leu-Lys 134-->Thr) mutants of Xenopus laevis B Cu,Zn superoxide dismutase has been studied by pulse radiolysis as a function of pH. The pH dependence curve of the wild-type enzyme can be deconvoluted by two deprotonation equilibria, at pH 9.3 (pK1) and at pH 11.3 (pK2). Catalytic rate measurements on single and double mutants indicate that pK1 is mainly due to the deprotonation of Lys 120 and Lys 134, with only a minor contribution from other surface basic residues, whereas pK2 is due to titration of the invariant Arg 141, likely coupled to deprotonation of the copper-bound water molecule. Accordingly, Brownian dynamics simulations carried out as a function of pH reproduce well the pH dependence of the catalytic rate, when the experimentally determined pKs are assigned to Lys 120, Lys 134, and Arg 141.
Argese,
Electrostatic control of the rate-determining step of the copper, zinc superoxide dismutase catalytic reaction.
1987, Pubmed
Argese,
Electrostatic control of the rate-determining step of the copper, zinc superoxide dismutase catalytic reaction.
1987,
Pubmed
Bannister,
Aspects of the structure, function, and applications of superoxide dismutase.
1987,
Pubmed
Battistoni,
Temperature-dependent protein folding in vivo--lower growth temperature increases yield of two genetic variants of Xenopus laevis Cu,Zn superoxide dismutase in Escherichia coli.
1992,
Pubmed
,
Xenbase
Calabrese,
Involvement of the copper in the inhibition of Cu,Zn superoxide dismutase activity at high pH.
1991,
Pubmed
Calabrese,
Substitution of arginine for lysine 134 alters electrostatic parameters of the active site in shark Cu,Zn superoxide dismutase.
1989,
Pubmed
Cocco,
Carbamoylation of Cu,Zn-superoxide dismutase by cyanate. Role of lysines in the enzyme action.
1982,
Pubmed
Connolly,
Solvent-accessible surfaces of proteins and nucleic acids.
1983,
Pubmed
Cudd,
Electrostatic interactions in the reaction mechanism of bovine erythrocyte superoxide dismutase.
1982,
Pubmed
Desideri,
Evolutionary conservativeness of electric field in the Cu,Zn superoxide dismutase active site. Evidence for co-ordinated mutation of charged amino acid residues.
1992,
Pubmed
,
Xenbase
Djinovic Carugo,
Crystal structure of the cyanide-inhibited Xenopus laevis Cu,Zn superoxide dismutase at 98 K.
1994,
Pubmed
,
Xenbase
Fielden,
Mechanism of action of superoxide dismutase from pulse radiolysis and electron paramagnetic resonance. Evidence that only half the active sites function in catalysis.
1974,
Pubmed
Fisher,
The role of arginine 143 in the electrostatics and mechanism of Cu,Zn superoxide dismutase: computational and experimental evaluation by mutational analysis.
1994,
Pubmed
Getzoff,
Faster superoxide dismutase mutants designed by enhancing electrostatic guidance.
1992,
Pubmed
Klapper,
Focusing of electric fields in the active site of Cu-Zn superoxide dismutase: effects of ionic strength and amino-acid modification.
1986,
Pubmed
O'Neill,
The effects of pH and various salts upon the activity of a series of superoxide dismutases.
1988,
Pubmed
O'Neill,
Potential repair of free radical adducts of dGMP and dG by a series of reductants. A pulse radiolytic study.
1985,
Pubmed
Polticelli,
Mutation of Lys-120 and Lys-134 drastically reduces the catalytic rate of Cu,Zn superoxide dismutase.
1994,
Pubmed
,
Xenbase
Polticelli,
Modulation of the catalytic rate of Cu,Zn superoxide dismutase in single and double mutants of conserved positively and negatively charged residues.
1995,
Pubmed
,
Xenbase
Polticelli,
Identification of the residues responsible for the alkaline inhibition of the activity of Cu,Zn superoxide dismutase: a study of native and chemically modified enzymes.
1995,
Pubmed
Rotilio,
Properties of the apoprotein and role of copper and zinc in protein conformation and enzyme activity of bovine superoxide dismutase.
1972,
Pubmed
Tainer,
Determination and analysis of the 2 A-structure of copper, zinc superoxide dismutase.
1982,
Pubmed
