Examination of surface-bound Ku-DNA complexes in an aqueous environment using MAC mode atomic force microscopy

Biosens Bioelectron. 2004 Nov 15;20(5):918-24. doi: 10.1016/j.bios.2004.06.023.

Abstract

In the development of biosensors, it is essential to understand how the signal-transducing element may perturb surface-bound proteins and nucleic acids. The tip of the atomic force microscope is such an element in atomic force microscopy. In this paper, we describe the influence of tip-sample interactions on the measured height of the DNA repair protein, Ku, that has been adsorbed onto a mica surface which was submerged in aqueous solution. We find that the measured height of the Ku molecule depends critically on whether or not it is associated with DNA. Additionally, we observed that the conditions (time and concentration) under which Ku is incubated with DNA, affect the appearance (number and type) of the DNA-Ku complexes observed.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biosensing Techniques / instrumentation
  • Biosensing Techniques / methods*
  • Coated Materials, Biocompatible / analysis
  • Coated Materials, Biocompatible / chemistry
  • DNA Helicases / analysis
  • DNA Helicases / chemistry*
  • DNA Helicases / ultrastructure*
  • DNA-Binding Proteins / analysis
  • DNA-Binding Proteins / chemistry
  • DNA-Binding Proteins / ultrastructure
  • Image Interpretation, Computer-Assisted / methods
  • Ku Autoantigen
  • Microscopy, Atomic Force / methods*
  • Nucleic Acid Conformation
  • Plasmids / analysis
  • Plasmids / chemistry*
  • Plasmids / ultrastructure*
  • Protein Binding
  • Protein Conformation
  • Surface Properties
  • Water / analysis
  • Water / chemistry*

Substances

  • Coated Materials, Biocompatible
  • DNA-Binding Proteins
  • Water
  • DNA Helicases
  • XRCC5 protein, human
  • Ku Autoantigen