ACTIVATION OF PHOSPHATES TO SUBSTITUTION(II) - COMPARISON OF CATALYZES INITIATED DIRECTLY BY VO2+ AND BY OXIDATION OF VO2+ BY MNO4-

被引：15

作者：

IMAMURA, T ^{[1
]}

HINTON, DM ^{[1
]}

BELFORD, RL ^{[1
]}

GUMPORT, RI ^{[1
]}

HAIGHT, GP ^{[1
]}

机构：

[1] UNIV ILLINOIS,SCH CHEM SCI,URBANA,IL 61801

来源：

JOURNAL OF INORGANIC BIOCHEMISTRY | 1979年 / 11卷 / 03期

基金：

美国国家卫生研究院;

关键词：

D O I：

10.1016/S0162-0134(00)80021-5

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

Vanadium(V)-induced hydrolyses of triphosphates in aqueous solutions were initiated in two ways: (1) oxidizing vanadium(IV)-polyphosphate complexes to produce metastable vanadium(V) complexes; (2) forming VO2+-polyphosphate complexes by acidification of solutions of VO43- and polyphosphate to yield equilibrium mixtures of V(V), polyphosphate, and their complexes. Hydrolysis rates for the complexes formed at 40°C ≥ T ≥ 25°C follow the order V2PPPi = 2(VPPPi) {all equal to} (VO2) ATP ≫ V(PPPi)2 {all equal to} PPPi. The hydrolysis of (V(V))2(PPPi) was not very temperature sensitive; the activation enthalpy appears small and the activation entropy large and negative. Mechanistic studies reveal that requirements for the activated state in metal-ion-catalyzed hydrolysis of polyphosphates include monodentate polyphosphate ligated cis to H2O or OH- in the coordination sphere of the metal ion: {A figure is presented}. © 1979.

引用

页码：241 / 259

页数：19

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