Triphosphates complexes

For example, Bachelard used [Mgtotai]/[ATPtotai ] = 1 in his rate studies, and he obtained a slightly sigmoidal plot of initial velocity versus substrate ATP concentration. This culminated in the erroneous proposal that brain hexokinase was allosterically activated by magnesium ions and by magnesium ion-adenosine triphosphate complex. Purich and Fromm demonstrated that failure to achieve adequate experimental control over the free magnesium ion concentration can wreak havoc on the examination of enzyme kinetic behavior. Indeed, these investigators were able to account fully for the effects obtained in the previous hexokinase study. ... 

Exotic and Troublesome Nuclei. - N MAS NMR of the nitrate ion and solid-state NMR of Mg(II) adenosine 5 -triphosphate complex have... 

ALA-dehydratase, and isocitrate dehydrogenase and decreases Na+, K -ATPase activity, Mg +-ATPase activity, and choline uptake into synaptosomes. In vitro, aluminum displaces magnesium from Mg +-ATP complexes, and it could thus antagonize virtually any phosphatetransferring reaction that uses Mg +-nucleotide triphosphate complexes. 

The a,7-coordinated triphosphate complex [(NH3)4CoP30io] has also been synthesized (121), but little has been reported on its hydrolytic reactivity. 

Kuntz, G. P. P., and Kotowycz, G. (1975). Biochemistry 14, 4144. A Nuclear Magnetic Resonance Relaxation Time Study of the Manganese(II)-Inosine 5 -Triphosphate Complex in Solution. 

Triphosphates and pyrophosphates can be estimated in the presence of each other and ortho and cyclic metaphosphates, with tris(ethylenediamine) cobalt chloride. At pH = 3.5, this latter reagent will form an insoluble triphosphate complex but not a pyrophosphate complex. Conversely at pH = 6.5, a pyrophosphate but not a triphosphate complex can be precipitated. Under either of these conditions ortho and cyclic metaphosphates will not give precipitates. 

As in the latter case the structure of the nucleotide base in the triphosphate complex was found to influence the metal ion environment... 

Rechnitz, G.A. and Mohan, M.S., 1970, Potassium-adenosine triphosphate complex formation constant measured with ion-selective electrodes. Science 168 1460. 

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