Influence of Albumin Configuration by the Chiral Polymer-Grafted Gold Nanoparticles

The interaction between nanoparticles (NPs) and proteins is a topic of high relevance for the medical application of NPs. This study reveals the molecular chirality on NP surfaces as an indirect regulator of the interaction between proteins and NPs. Poly(N-acryloyl-valine) (PAV) polymers with D- and L-configurations were conjugated onto gold NPs with a size of 5 nm to obtain the L-PAV-AuNPs and D-PAV-AuNPs, respectively. They had same chemical composition and surface grafting density but different surface chirality. The isothermal titration calorimetry results showed that adsorption of bovine serum albumin onto the L-PAV-AuNPs and D-PAV-AuNPs was primarily driven by electrostatic interaction. Dynamic light scattering, circular dichroism spectroscopy, fluorescence quenching, and isothermal titration calorimetry characterizations revealed that bovine serum albumin molecules adopted both side-on and end-on configurations on the D-PAV-AuNPs, whereas only end-on configuration on the L-PAV-AuNPs.