Lanthanide ions promote the hydrolysis of 2,3-Bisphosphoglycerate

ISSN： 0966-0844

Source： BioMetals, Vol.17, Iss.4, 2004-08, pp. : 423-433

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Abstract

The ³¹P NMR studies showed that lanthanide ions promote the site-specific hydrolysis of 2,3-Bisphosphoglycerate (BPG) at pH 7.4 by cleaving the 2′ phosphomonoester bond. The effect of fourteen trivalent lanthanide ions and Sc³⁺, and Y³⁺ were compared by the percentage of hydrolysis obtained by determining the inorganic phosphate produced. All the trivalent lanthanide ions promote the hydrolysis, but Sc³⁺ not. Among them, Ce³⁺ affects the reaction mostly. This was mainly attributed to the autooxidation of Ce³⁺ to Ce⁴⁺, since the promoting effect of Ce³⁺ is related to the increasing Ce⁴⁺ amount in the solution and depressed by adding sulphite. Ce⁴⁺ promotes the hydrolysis more efficiently than Ce³⁺ do. The pseudo first-order rate constant for the hydrolysis of BPG by Ce(SO₄)₂ (18.7 mM) at pH 1 and pH 2, 37 °C is 3.1 h⁻¹ and 0.65 h⁻¹ respectively. A mechanism with a hydroxo species as reactive intermediate was proposed for the trivalent lanthanide ions. The site-specificity was explainable by this mechanism.