Synthesis of new aluminophosphate materials with the FAU and AFR structure-types

The structure of piperazinium l-tartrate, C4H12N22+.C4H4O62−, exhibits a complex three-dimensional network of hydrogen bonds. The divalent anions create puckered layers via two O—H⋯O hydrogen bonds and neighbouring layers are then crosslinked by four N—H⋯O interactions through the divalent cations.

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Tartrate

10.1107/s0108270195016374

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23Na NMR investigation of the interaction between DNA and divalent metallic cations

Journal of Biological Physics (1994)

Dan Vasilescu Seddik Ansiss G. Mallet

Divalent

10.1007/bf00700469

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Citations (8)

Biological Significance of Divalent Metal Ion Binding to 14-3-3 Proteins In Relationship to Nitrate Reductase Inactivation

Plant and Cell Physiology (1998)

Gurdeep S. Athwal Joan L. Huber Steven C. Huber

In this report we address two questions regarding the regulation of phosphorylated nitrate reductase (pNR; EC 1.6.6.1) by 14-3-3 proteins. The first concerns the requirement for millimolar concentrations of a divalent cation in order to form the inactive pNR: 14-3-3 complex at pH 7.5. The second concerns the reduced requirement for divalent cations at pH 6.5. In answering these questions we highlight a possible general mechanism involved in the regulation of 14-3-3 binding to target proteins. We show that divalent cations (e.g. Ca2+, Mg2+ and Mn2+) bind directly to 14-3-3s, and as a result cause a conformational change, manifested as an increase in surface hydrophobicity. A similar change is also obtained by decreasing the pH from pH 7.5 to pH 6.5, in the absence of divalent cations, and we propose that protonation of amino acid residues brings about a similar effect to metal ion binding. A possible regulatory mechanism, where the 14-3-3 protein has to be "primed" prior to binding a target protein, is discussed.

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Conformational change

10.1093/oxfordjournals.pcp.a029303

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Citations (55)

Computer modelling of divalent, trivalent and tetravalent ion doping in LiCaAlF₆and LiSrAlF₆

Journal of Physics Condensed Matter (2004)

Jomar B. Amaral Ashley Lewis Mário E.G. Valério Robert A. Jackson

This paper describes a computational study of the mixed metal fluorides LiCaAlF6 and LiSrAlF6, doped with divalent (Pb2+, Co2+ and Ni2+), trivalent (Cr3+, Fe3+ and Y3+) and tetravalent (Si4+) ions. For each of the frameworks, all three cation sites were considered, as well as a range of charge compensation mechanisms. For the divalent dopants, substitution at the divalent host site is preferred, whilst for the trivalent dopants, Co3+ and Fe3+ prefer the Al3+ site, and Y3+ shows behaviour similar to the rare earths. Finally, it is found that Al3+ is the preferred site for substitution by Si4+ in both host frameworks.

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10.1088/0953-8984/16/47/023

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Concerning the incorporation of divalent cations into the high-temperature modification of Li2SO4

Solid State Ionics (1996)

П. П. Федоров

Divalent

Tetrahedron

10.1016/s0167-2738(96)83013-x

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Citations (7)