Tuning the Catalytic Activity and Substrate Specificity of Peptide‐Nanoparticle Conjugates

Abstract The immobilization of cysteine‐containing peptides onto the surface of gold nanoparticles (Pep‐Au‐MPCs) emerged as a promising strategy towards the development of artificial enzymes. In this context we studied the effect the location of the catalytic unit within the peptide‐monolayer relative to the nanoparticle surface has on the esterolytic activity and substrate specificity of three Pep‐Au‐MPCs, that only differ in the position of the catalytic unit (surface proximal, intermediate, surface distal). Rates of ester hydrolysis were found to correlate with the hydrophobicity of the substrate and the position of the catalytic unit. Highly hydrophobic ester substrates are cleaved more efficiently surface proximal, whereas less hydrophobic substrates showed higher rates of hydrolysis in the intermediate region of the monolayer. Our studies reveal the importance the position of the catalytic center has on the catalytic activity and substrate specificity of peptide‐nanoparticle conjugates.