Single-strand Conformation Polymorphism Studied by Elimination Voltammetry - New Challenge in DNA Sensing
| Authors | |
|---|---|
| Year of publication | 2012 |
| Type | Article in Proceedings |
| Conference | 45th Heyrovsky Discussion Electrochemistry of Biopolymers and Bioactive Compounds, Book of Abstract |
| MU Faculty or unit | |
| Citation | |
| Field | Physical chemistry and theoretical chemistry |
| Keywords | SSCP; single-strand conformation polymorphism;cytosine;i-motif;LSV;EVLS;ODN |
| Description | Single-strand conformation polymorphism (SSCP) is defined as a conformational difference of single-stranded nucleotide sequences. For example, the cytosine (C)-rich single-stranded DNA can adopt i-motif structure consisting of intercalated hemiprotonated C–C+ base pairing [1,2]. Using linear sweep voltammetry (LSV) and elimination voltammetry with linear scan (EVLS) [3,4] we studied the effect of pH, the number and sequence of C in homo and hetero-ODN chains on the reduction signals on mercury electrodes in buffered and non-buffered solutions. The EVLS procedure in connection with adsorptive stripping techniques (AdS) was found to be capable of revealing the changed ODN structure on a mercury electrode surface and reflects the single-strand chain polymorphism. For this purpose the EVLS function E4 conserving the diffusion current and eliminating the kinetic and charging current components was used. Compared to common voltammetric methods, the EVLS E4 function is capable of providing 7-15 fold sensitivity and a better resolution of redox signals of the nucleobases in the ODN chain [5]. This benefit is particularly pronounced in the case of an adsorbed substance yielding a well-developed elimination signal (peak-counterpeak) which does not require a baseline correction. Changes in the nucleotide sequence, owing to a polymorphism, are expected to alter the secondary structure of the ODN molecules resulting in a shift in their redox and adsorption properties. Although SSCP analysis is primarily associated with the electrophoretic methods and the polymerase chain reaction [6] our AdS EVLS can quickly identify different conformers in solutions and on the electrode surface in dependence on experimental conditions such as temperature, pH, ionic strength and buffer components. |
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