Interactions of fluorescent dye SYBR Green I with natural and 7-deazaguanine-modified DNA studied by fluorescence and electrochemical methods
| Authors | |
|---|---|
| Year of publication | 2016 |
| Type | Article in Periodical |
| Magazine / Source | Monatshefte fur Chemie |
| MU Faculty or unit | |
| Citation | |
| Web | http://link.springer.com/article/10.1007%2Fs00706-015-1578-5 |
| Doi | http://dx.doi.org/10.1007/s00706-015-1578-5 |
| Field | Physical chemistry and theoretical chemistry |
| Keywords | DNA; 7-Deazaguanine; PCR; Fluorescence; Quenching; DNA interaction; DNA modification; Electrochemical oxidation; Graphite electrode |
| Description | SYBR Green I (SG) is a fluorescent dye applied in various techniques of DNA analysis, including fluorescent staining of electrophoretic gels, quantitative polymerase chain reaction, etc. SG binds selectively to double-stranded DNA via intercalation and minor groove interactions, resulting in a considerable enhancement of fluorescence of the dye. Modification of DNA by partial or full replacement of natural purine nucleobase guanine (G) with its synthetic analog 7-deazaguanine (G*) or its derivatives was shown to cause the SG fluorescence quenching. In this paper, we present a comparative study of interactions of SG with natural DNA fragments and with DNA fragments modified with G* by means of fluorescence and electrochemical methods. Competition between unmodified (forming strongly fluorescent complex with SG) and fully G*-modified (not contributing significantly to overall fluorescence signal) DNA fragments for the dye was studied via changes in the fluorescence intensity. In addition, association interactions of natural or G*-modified DNA with SG in solution were monitored by adsorptive transfer stripping square wave voltammetry at a pyrolytic graphite electrode using a signal of SG electrooxidation. We show that SG binds both natural and G*-modified DNA with similar apparent affinity and selectivity for the double-stranded DNA. [GRAPHICS] . |