The catalytic activity of a mutant of Photobacterium leiognathi Cu,Zn superoxide dismutase in which the Glu59 residue, conserved in most bacterial variants of the enzyme, has been replaced by glutamine was investigated by pulse radiolysis. At neutral pH the enzyme was found to have a k(cat)/K(M) of 1.0 ± 0.1 x 1010 M-1 s-1 the highest value ever found for any superoxide dismutase. Brownian dynamics simulation suggests that such a high value is due to an enhanced substrate attraction by the modified electric field distribution. The mutant is also characterized by an active-site widely accessible for the solvent, since iodide is able to interact with the copper atom with an affinity constant twice as high as that found in the native enzyme. The large solvent accessible surface of the copper site together with a favorable distribution of the protein-generated electric field gives rise to the most efficient enzyme ever found with activity close to the diffusion limit.

Folcarelli, S., Venerini, F., Battistoni, A., O'Neill, P., Rotilio, G., Desideri, A. (1999). Toward the engineering of a super efficient enzyme. BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS, 256(2), 425-428 [10.1006/bbrc.1999.0211].

Toward the engineering of a super efficient enzyme

BATTISTONI, ANDREA;ROTILIO, GIUSEPPE;DESIDERI, ALESSANDRO
1999-01-01

Abstract

The catalytic activity of a mutant of Photobacterium leiognathi Cu,Zn superoxide dismutase in which the Glu59 residue, conserved in most bacterial variants of the enzyme, has been replaced by glutamine was investigated by pulse radiolysis. At neutral pH the enzyme was found to have a k(cat)/K(M) of 1.0 ± 0.1 x 1010 M-1 s-1 the highest value ever found for any superoxide dismutase. Brownian dynamics simulation suggests that such a high value is due to an enhanced substrate attraction by the modified electric field distribution. The mutant is also characterized by an active-site widely accessible for the solvent, since iodide is able to interact with the copper atom with an affinity constant twice as high as that found in the native enzyme. The large solvent accessible surface of the copper site together with a favorable distribution of the protein-generated electric field gives rise to the most efficient enzyme ever found with activity close to the diffusion limit.
1999
Pubblicato
Rilevanza internazionale
Articolo
Sì, ma tipo non specificato
Settore BIO/10 - BIOCHIMICA
English
Con Impact Factor ISI
copper zinc superoxide dismutase; enzyme variant; glutamic acid; iodide; article; catalysis; electric field; enzyme activity; enzyme kinetics; genetic conservation; genetic engineering; molecular dynamics; nonhuman; pH; photobacterium leiognathi; priority journal; pulse radiolysis; Amino Acid Substitution; Anions; Binding Sites; Catalysis; Computer Simulation; Copper; Diffusion; Electrostatics; Hydrogen-Ion Concentration; Iodides; Kinetics; Osmolar Concentration; Photobacterium; Protein Engineering; Protons; Pulse Radiolysis; Solvents; Superoxide Dismutase; Titrimetry; Water; Bacteria (microorganisms); Felis catus; Negibacteria; Photobacterium leiognathi
Folcarelli, S., Venerini, F., Battistoni, A., O'Neill, P., Rotilio, G., Desideri, A. (1999). Toward the engineering of a super efficient enzyme. BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS, 256(2), 425-428 [10.1006/bbrc.1999.0211].
Folcarelli, S; Venerini, F; Battistoni, A; O'Neill, P; Rotilio, G; Desideri, A
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2108/55141
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