Design of protein linkers for the controlled assembly of nanoparticles

Abstract

In this thesis, a peptide (-CHKKPSKSC-, named as STB1) with specific binding ability to TiO2 and SiO2 NPs was first isolated using phage surface display technique. The binding behavior of phage particles harboring STB1 was investigated using quartz crystal microbalance with energy dissipation measurement (QCM-D). And the binding mechanism was probed using a series of STB1 mutants. It was found that the binding of STB1 to TiO2 and SiO2 is largely governed by electrostatic interaction. Subsequently, STB1 was fused to a specific DNA-binding protein, lac repressor (LacI), by genetic engineering. The STB1-fused LacI (LacI-STB1) shows alerted binding behavior to TiO2 and SiO2 compared to wild-type LacI, and it is able to simultaneously bind to two different ligands: DNA and TiO2 (or SiO2) NPs. Finally, it was successfully demonstrated that TiO2 NPs were assembled on DNA strands using LacI-STB1 as an erector.