Carbamoylation of Cu,Zn‐superoxide dismutase by cyanate

FEBS Letters

Barra, Donatella¹  Bossa, Francesco²  Rossi, Luisa²  Cocco, Dina²  Rotilio, Giuseppe² 

[1] Institute of Biological Chemistry, University of Camerino, Camerino, Italy;Gruppo di Chimica Biologica e Strutturistica Chimica and CNR Center for Molecular Biology, University of Rome, Italy

关键词: Superoxide dismutase;    Carbamoylation;    Lysine neutralization;    Electrostatic interactions;    in enzyme catalysis;    Ionic strength;    effect on enzymes;   

DOI  :  10.1016/0014-5793(82)80756-4

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Reaction with cyanate leads to a reversible change of the EPR spectrum of Cu,Zn-superoxide dismutase and to time-dependent carbamoylation of the lysine residues of the enzyme, producing a stable covalent derivative with more negative charge. The carbamoylated enzyme is less active than the native enzyme in spite of unaltered EPR spectra. The extent of this inactivation is much less when the enzyme activity is measured at low ionic strength. These results show that integrity of the active site is not the sole factor playing a role in the enzyme mechanism and that the ionic strength effect is related to electrostatic interactions between O⁻ ₂ and surface charges of the protein.

【 授权许可】

Unknown