Computational design of peptide-Au cluster probe for sensitive detection of αIIbβ3 integrin

We have designed a novel peptide-Au cluster probe to specifically bind to alpha(IIb)beta(3) integrin. As indicated by molecular dynamics (MD) simulations, the binding mode of the native ligand of alpha(IIb)beta(3) integrin, gamma C peptide, can be realized by the designed probe. More importantly, the peptide-Au probe can provide multiple coating peptides to form additional salt bridges with protein, and the binding stability of the probe is comparable to the native ligand. The designed probe was then successfully synthesized. The specific binding in a cellular environment was validated by colocalization analysis of confocal microscopy. In addition, the binding affinity was confirmed by atomic force microscopy (AFM) based single molecule force spectroscopy. Our results suggest the combination of computational design and experimental verification can be a useful strategy for the development of nanoprobes.