Monitoring the Instant Creation of a New Fluorescent Signal for Evaluation of DNA Conformation Based on Intercalation Complex


Uzumcu A. T., Güney O., Okay O.

JOURNAL OF FLUORESCENCE, vol.28, pp.1325-1332, 2018 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 28
  • Publication Date: 2018
  • Doi Number: 10.1007/s10895-018-2294-4
  • Journal Name: JOURNAL OF FLUORESCENCE
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.1325-1332
  • Istanbul Technical University Affiliated: Yes

Abstract

Here we report the monitoring the instant creation of a new fluorescent signal (FS) aroused from a positively charged water-soluble fluorogenic probe, ethidium bromide (EtBr) in the presence of a radical initiator, ammonium persulfate (APS) and an accelerator, tetraethylmetilendiamine (TEMED) for evaluation of deoxyribonucleic acid (DNA) conformation. The results revealed that the occurred FS ((ex)=430nm; (max)=525nm) is a reduced form of EtBr ((ex)=480nm; (max)=617nm) and it is completely distinct from hydroethidine ((ex)=350nm; (max)=430nm), which is two-electron reduced form of EtBr. It was noticed that EtBr was reduced to a new FS during the polymerization of N, N dimethyacrylamide (DMAA) too, at 25 degrees C in the presence of APS and TEMED or at 55 degrees C with only APS, and the rate of formation of FS was increased upon treatment time. The effect of nanoclays such as Laponite XLG (R) and Laponite XLS (R), which provide a protective environment for DNA in nature, were also investigated through the reduction process of EtBr in the absence and presence of a water soluble monomer DMAA. We demonstrated that DNA conformation might be evaluated by monitoring FS effectuated during the reduction of EtBr in the presence of nanoclays having positively and negatively charged surfaces. Protective property of DNA against the formation of reduced product was elucidated by carrying out the polymerization at 55 degrees C. The results revealed that the monitoring of formation of FS in the presence of radical initiator could lead to elucidate the conformation of DNA upon formation of intercalator complex.