CuCoO Nanoparticles as a Nanoprotease for Selective Proteolysis with High Efficiency at Room Temperature.

Many nanoproteases contain tetravalent metal ions and catalyze peptide-bond hydrolysis only at high temperature (60 °C). Here, we report a new and effective strategy to explore nanoproteases from nanoparticles containing low valent metal ions. We found that flower-like CuCoO nanoparticles (CuCoO NPs) containing low valent Cu possessed excellent catalytic activity towards selective cleavage of peptide bonds with hydrophobic residues in bovine serum albumin (BSA) at room temperature. CuCoO NPs exhibited excellent stability and had great reusability. CuCoO NPs also hydrolyzed heat-denatured and surfactant-denatured BSA. Mechanism analysis revealed that the high Lewis acidity of Co and the low valence of Cu were both essential for the high protease activity of CuCoO NPs. The flower-like structure of CuCoO NPs and the strong nucleophilicity of Cu -bound hydroxyl endow them with excellent catalytic performance. The findings open a new way for the design and discovery of high-efficiency nanoproteases.