Self-assembled donor comprising quantum dots and fluorescent proteins for long-range fluorescence resonance energy transfer

J Am Chem Soc. 2008 Apr 9;130(14):4815-27. doi: 10.1021/ja078243f. Epub 2008 Mar 14.

Abstract

We report on the development of a self-assembled donor for long-range fluorescence resonance energy transfer (FRET). To this end, a three-chromophore FRET (3Ch-FRET) system was constructed, which consists of a luminescent quantum dot (QD), enhanced yellow fluorescent proteins (EYFP), and Atto647-dye-modified oligonucleotides. The system was assembled by electrostatic binding of covalent EYFP-ssDNA conjugate to the QD and subsequent hybridization with complementary oligonucleotides labeled with Atto647-dye. The final conjugates comprise three different two-chromophore FRET (2Ch-FRET) subsystems, QD/EYFP, QD/Atto647, and EYFP/Atto647, respectively, which were studied in detail by steady-state and time-resolved photoluminescence measurements. The helicity of DNA allowed us to control donor/acceptor separations and thus enabled the detailed analysis of the various FRET processes. We found that the 2Ch-FRET and the 3Ch-FRET (QD/EYFP/Atto647) systems revealed FRET efficiencies and transfer rates that were affected by the availability of distinct FRET pathways. The derived energy-transfer efficiencies and Förster radii indicated that within the 3Ch-FRET system, the 2Ch-FRET subsystem QD/EYFP showed highest FRET efficiencies ranging from 64 to 72%. Thus, it can be used as a powerful donor system that combines the intrinsic advantages of QDs (large and spectrally broad absorption cross section) and EYFP (high quantum yield) and enables long-distance FRET processes for donor-acceptor distances of up to 13 nm.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / chemistry*
  • DNA, Single-Stranded / chemistry*
  • Fluorescence Resonance Energy Transfer / methods*
  • Luminescent Measurements / methods
  • Luminescent Proteins / chemistry*
  • Models, Molecular
  • Oligonucleotides / chemical synthesis
  • Oligonucleotides / chemistry*
  • Quantum Dots*
  • Spectrometry, Fluorescence
  • Spectrophotometry, Ultraviolet

Substances

  • Bacterial Proteins
  • DNA, Single-Stranded
  • Luminescent Proteins
  • Oligonucleotides
  • yellow fluorescent protein, Bacteria