Capture of unstable protein complex on the streptavidin-coated single-walled carbon nanotubes

Purification of unstable protein complexes is a bottleneck for investigation of their 3D structure and in protein-protein interaction studies. In this paper, we demonstrate that streptavidin-coated single-walled carbon nanotubes (Strep center dot SWNT) can be used to capture the biotinylated DNA-EcoRI complexes on a 2D surface and in solution using atomic force microscopy and electrophoresis analysis, respectively. The restriction enzyme EcoRI forms unstable complexes with DNA in the absence of Mg2+ Capturing the EcoRI-DNA complexes on the Strep center dot SWNT succeeded in the absence of Mg2+, demonstrating that the Strep center dot SWNT can be used for purifying unstable protein complexes.