Targeting the Surface of the Protein 14-3-3 by Ultrasmall (1.5 nm) Gold Nanoparticles Carrying the Specific Peptide CRaf

Chembiochem. 2021 Apr 16;22(8):1456-1463. doi: 10.1002/cbic.202000761. Epub 2021 Jan 28.

Abstract

The surface of ultrasmall gold nanoparticles with an average diameter of 1.55 nm was conjugated with a 14-3-3 protein-binding peptide derived from CRaf. Each particle carries 18 CRaf peptides, leading to an overall stoichiometry of Au(115)Craf(18). The binding to the protein 14-3-3 was probed by isothermal titration calorimetry (ITC) and fluorescence polarization spectroscopy (FP). The dissociation constant (KD ) was measured as 5.0 μM by ITC and 0.9 μM by FP, which was close to the affinity of dissolved CRaf to 14-3-3σ. In contrast to dissolved CRaf, which alone did not enter HeLa cells, CRAF-conjugated gold nanoparticles were well taken up by HeLa cells, opening the opportunity to target the protein inside a cell.

Keywords: Gold; nanoparticles; peptides; proteins; supramolecular chemistry.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 14-3-3 Proteins / chemistry*
  • Gold / chemistry*
  • HeLa Cells
  • Humans
  • Metal Nanoparticles / chemistry*
  • Particle Size
  • Peptides / chemistry*
  • Surface Properties

Substances

  • 14-3-3 Proteins
  • Peptides
  • Gold