Mechanism of Renaturation of Pyruvate Kinase of Saccharomyces carlsbergensis: Activation by L-Valine and Magnesium and Manganese Ions
AUTOR(ES)
Bornmann, Lothar
RESUMO
Pyruvate kinase (EC 2.7.1.40) of S. carlsbergensis is a tetrameric enzyme, composed of four identical subunits each of which contains 1 mole of L-valine noncovalently bound. The enzyme readily dissociates into monomeric units. L-Valine and magnesium or manganese ions are specific primers of the renaturation process of the enzyme. The amino acid induces renaturation with a K0.5 of 17 μM and a pseudo first-order rate constant of 0.019 min-1 at 25° with respect to the monomeric species, indicating that L-valine influences the folding of the monomeric form from a disordered state to its native conformation being followed by a spontaneous reassociation with formation of the tetrameric enzyme. Independently, magnesium and manganese ions induce the renaturation with a first-order rate constant of the same magnitude.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=388263Documentos Relacionados
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