The specific interaction between two C:C mismatch base pairs and silver (I) cation

Abstract

We have already found that a single silver (I) cation specifically binds to a single C:C mismatch base pair in heteroduplex, which increases the melting temperature of heteroduplex involving a single C:C mismatch base pair by about 4 degrees C. Here, to examine the thermodynamic properties involving two C:C mismatch base pairs, we analyzed the interaction between silver (I) cations and heteroduplex involving two C:C mismatch base pairs by isothermal titration calorimetry. The difference in the positions of the two C:C mismatch base pairs did not significantly affect the magnitudes of the stoichiometry and the thermodynamic parameters for the interaction between silver (I) cations and the two C:C mismatch base pairs. Two silver (I) cations bind with two C:C mismatch base pairs. The binding affinity for the second silver (I) cation was similar to that for the first silver (I) cation. Our results certainly support the idea that addition of the silver (I) cation is a promising strategy for the C:C mismatch base pair detection in the heteroduplex analysis and may eventually lead to progress in SNP genotyping.