Ethidium Bromide and SYBR Green I Interact with Lipid Micelles

AG, GARRO; PS, VELEZ; N, MIOTTI; RV, ALASINO; DM BELTRAMO

Chemical Sciences Journal

OMICS Internetional

Año: 2017 vol. 08

Ethidium Bromide and SYBR Green I are usual examples of ligands that specifically bindsto DNA by intercalation. Here we describe that micelles of gangliosides, alipidic family of sialoglycosphingolipids which are the most important lipidsin central nervous system, are able to interact with both, EtBr and SYBR Green I and fluoresce after UV lightexcitation.  The interaction isnot affected by the presence of high saline concentration (1M NaCl), a conditionwhich dissociate potential electrostatic interaction between amino andcarboxylic acid groups present in EtBr and GM1 respectively; instead, increasethe fluorescense of EtBr/GM1 micelles. This result suggests that the EtBr is located inside thehydrophobic core of the micelle. Moreover, theSYBR Green I associated ganglioside micelles does not emit green light as withDNA, but there was a change in the light spectrum towards higher wave lengths,now emitting orange light.It was alsofound that the interaction with these dyes is not affected when the micelleswere preloaded with other molecules (paclitaxel albumin). Moreover, furtherstudies showed that this interaction is not observed with other ionic andnonionic classic detergent micelles, and even the addition of these moleculesto GM1 micelles interferes with the described EtBr / GM1 interaction.