Functional characterization and atomic force microscopy of a DNA repair protein conjugated to a quantum dot

Nano Lett. 2008 Jun;8(6):1631-7. doi: 10.1021/nl080316l. Epub 2008 Apr 30.

Abstract

Quantum dots (QDs) possess highly desirable optical properties that make them ideal fluorescent labels for studying the dynamic behavior of proteins. However, a lack of characterization methods for reliably determining protein-quantum dot conjugate stoichiometry and functionality has impeded their widespread use in single-molecule studies. We used atomic force microscopic (AFM) imaging to demonstrate the 1:1 formation of UvrB-QD conjugates based on an antibody-sandwich method. We show that an agarose gel-based electrophoresis mobility shift assay and AFM can be used to evaluate the DNA binding function of UvrB-QD conjugates. Importantly, we demonstrate that quantum dots can serve as a molecular marker to unambiguously identify the presence of a labeled protein in AFM images.

Publication types

  • Research Support, N.I.H., Intramural

MeSH terms

  • Binding Sites
  • DNA Repair Enzymes / chemistry*
  • DNA Repair Enzymes / ultrastructure*
  • Microscopy, Atomic Force / methods*
  • Protein Binding
  • Protein Interaction Mapping / methods*
  • Quantum Dots

Substances

  • DNA Repair Enzymes