Selective protein hydrolysis catalyzed by LaCoO3 nanoparticles

Abstract

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 LaCoO3 nanoparticles (LaCoO3 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. LaCoO3 NPs have high stability and excellent reuse performance. LaCoO3 NPs also hydrolyze surfactant-denatured and heat-denatured BSA. Preliminary mechanism analysis indicates that the low valency of Co2+ and the strong Lewis acidity of La3+ played key roles in the high protease activity of LaCoO3 NPs. This work demonstrates that LaCoO3 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.