Quantitative analysis of monovalent counterion binding to random-sequence, double-stranded DNA using the replacement ion method.

ABSTRACT: A variation of affinity capillary electrophoresis, called the replacement ion (RI) method, has been developed to measure the binding of monovalent cations to random sequence, double-stranded (ds) DNA. In this method, the ionic strength is kept constant by gradually replacing a non-binding ion in the solution with a binding ion and measuring the mobility of binding and non-binding analytes as a function of binding ion concentration. The method was validated by measuring the binding of Li+ ions to adenosine nucleotides; the apparent dissociation constants obtained by the RI method are comparable to literature values obtained by other methods. The binding of Tris+, NH4+, Li+, Na+, and K+ to dsDNA was then investigated. The apparent dissociation constants observed for counterion binding to a r

SUBMITTER: Stellwagen E 

PROVIDER: S-EPMC2532990 | biostudies-literature | 2007 Feb

REPOSITORIES: biostudies-literature