# Critical cation balance in B \rightarrow Z transition: role of $Li^+$

Ramesh, N and Brahmachari, Samir K (1983) Critical cation balance in B \rightarrow Z transition: role of $Li^+$. In: FEBS Letters, 164 (1). pp. 33-37.

 PDF sdarticle.pdf Restricted to Registered users only Download (434Kb) | Request a copy

## Abstract

The sodium salt of poly(dG-dC) is known to exhibit a B \rightarrow Z transition in the presence of various previous termcationsnext term and 60% alcohol. We here show that the lithium salt of poly(dG-dC) does not undergo B \rightarrow Z transition in the presence of 60% alcohol since $Li^+$ with its large hydration shell cannot stabilize the Z-form. On the other hand, high concentrations of $Mg^{2+}$ or micromolar concentrations of the cobalt hexamine complex which are known to stabilize the Z-form can compete with $Li^+$ for charge neutralization and hence bring about a B \rightarrow Z transition in the same polymer. From the model building studies the mode of action of the cobalt—hexamine complex in stabilizing the Z-form is postulated.

Item Type: Journal Article Copyright of this article belongs to Elsevier. B → Z transition;Circular dichroism;Poly(dG-dC) Li salt;Cobalt—hexamine binding Division of Biological Sciences > Molecular Biophysics Unit 24 Jun 2008 19 Sep 2010 04:44 http://eprints.iisc.ernet.in/id/eprint/13565