Magnetic isotope effect of magnesium in phosphoglycerate kinase phosphorylation
AUTOR(ES)
Buchachenko, Anatoly L.
FONTE
National Academy of Sciences
RESUMO
Phosphoglycerate kinase (PGK) is found to be controlled by a 25Mg2+-related magnetic isotope effect. Mg2+ nuclear spin selectivity manifests itself in PGK-directed ADP phosphorylation, which has been clearly proven by comparison of ATP synthesis rates estimated in reaction mixtures with different Mg isotopy parameters. Both pure 25Mg2+ (nuclear spin 5/2, magnetic moment +0.85) and 24Mg2+ (spinless, nonmagnetic nucleus) species as well as their mixtures were used in experiments. In the presence of 25Mg2+, ATP production is 2.6 times higher compared with the yield of ATP reached in 24Mg2+-containing PGK-based catalytic systems. The chemical mechanism of this phenomenon is discussed. A key element of the mechanism proposed is a nonradical pair formation in which 25Mg+ radical cation and phosphate oxyradical are involved.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1182455Documentos Relacionados
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