Application of a Metal-Mediated Base Pair to the Detection of Medicinally Relevant Single Nucleotide Polymorphisms

A highly stabilizing metal-mediated base pair formed from the canonical nucleobase cytosine (C), the transition metal ion Ag-I, and the artificial nucleobase 1H-imidazo[4,5-f]-[1,10] phenanthroline (P) was used in the generation of molecular beacons for the detection of medicinally relevant single nucleotide polymorphisms (SNPs) based on either a C -> T or a T -> C transition (T: thymine). The beacons exploit the fact that a P-C pair is strongly stabilized in the presence of Ag-I, whereas a P-T pair is significantly destabilized. A direct correlation of oligonucleotide sequence, duplex stability prior to the addition of Ag-I, stabilization due to metal-mediated base pair formation, and performance of the molecular beacon was not observed. Nonetheless, the data show for the first time that metal-mediated base pairing can be applied in the detection of medicinally relevant SNPs.