Effect of metal ions on the activity of cascein kinase II from Xenopus laevis

FEBS Letters

Hinrichs, María V.¹  Jedlicki, Ana¹  Allende, Catherine C.²  Gatica, Marta¹  Allende, Jorge E.¹ 

[1] Departamento de Bioquímica, Facultad de Medicina Universidad de Chile Casilla 70086, Santiago 7, Chile;Departamento de Biologiá, Facultad de Ciencias, Universidad de Chile Casilla 70086, Santiago 7, Chile

关键词: CaScin kinase II;    CaScin kinase II α and β subunits;    Divalent metal ion;    Xenopus laevis;   

DOI  :  10.1016/0014-5793(93)81157-U

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

CaSein kinase II purified from the nuclei of Xenopus laevis oocytes as well as the recombinant α and β subunits of the X. laevis CKII, produced in E. coli from the cloned cDNA genes, were tested with different divalent metal ions. The enzyme from both sources was active with either Mg²⁺, Mn²⁺, or Co²⁺. Optimal concentrations were 7–10 mM for Mg²⁺, 0.5–0.7 mM for Mn²⁺ and 1–2 mM for Co²⁺. In the presence of Mn²⁺ or Co²⁺ the enzyme used GTP more efficiently than ATP as a phosphate donor while the reverse was true in the presence ofMg²⁺. The apparent K _m values for both nucleotide triphosphates were greatly decreased in the presence of Mn²⁺ as compared with Mg²⁺. Addition of Zn²⁺ (above 150 μM) to an assay containing the optimal Mg²⁺ ion concentration caused strong inhibition of both holoenzyme and α subunit. Inhibition of the holoenzyme by 400 μM Ni²⁺ could be reversed by high concentrations of Mg²⁺ but no reversal of this inhibition was observed with the α subunit.

【 授权许可】

Unknown