Selective protein hydrolysis catalyzed by LaCoO3 nanoparticles

Many nanoproteases contain quadrivalent metal ions and catalyze peptide-bond hydrolysis only at high temperature (60 °C). Their catalytic efficiency is much less than natural proteases. It leaves a great challenge to develop efficient and reusable nanoproteases with high protease activity at room temperature. Here, we have explored nanoproteases from eight low valent metal oxide nanoparticles . Among these nanoparticles, only perovskite LaCoO 3 nanoparticles (LaCoO 3 NPs) selectively hydrolyze bovine serum albumin (BSA) at X-Lys peptide bonds at 20 °C, producing fragments of 10–45 kDa, which are adapted to middle-down proteomics. LaCoO 3 NPs have high stability and excellent reuse performance. LaCoO 3 NPs also hydrolyze surfactant-denatured and heat-denatured BSA. Preliminary mechanism analysis indicates that the low valency of Co 2+ and the strong Lewis acidity of La 3+ played key roles in the high protease activity of LaCoO 3 NPs. This work demonstrates that LaCoO 3 NPs are a high promising nanoprotease to selectively hydrolyze insoluble and soluble proteins at 20 °C. More importantly, our findings highlight that manufacture of low valent metal ions-contained nanoparticle is an effectual strategy for fabricating high-efficiency nanoprotease.