A unique approach to enhance catalytic performance of Lipase by in situ formation of silver nanoclusters

The purpose of this study was to design and engineer a simple approach to enhance the catalytic activity and thermal stability of Lipase. Lipase is an enzyme with exciting multifarious applications in the industry. In this respect, we observed that the catalytic activity of Lipase was enhanced when it was subjected to in situ synthesis of silver nanoclusters (AgNCs) within the enzyme structure. At alkaline pH, the in situ synthesis of AgNCs inside Lipase altered its activity, and the resulting nanohybrid showed enhanced enzymatic activity. Compared with the catalytic efficiency of free Lipase (72.33 min -1 mM -1 ), the Lipase clustered with silver nanoclusters (L-AgNCs) showed enhanced catalytic efficiency (109.22 min -1 mM -1 ). Thermodynamic parameters of free Lipase and L-AgNCs were determined by calculating activation energy (Ea) values to be 19.92 KJ mol-1 and 17.29 KJ mol-1, respectively. The lower activation energy of L-AgNCs designates it to be more stabilized and highly active to bind with the substrate having a higher rate of reaction instead of free Lipase. Molecular docking analysis showed that silver binds to amino acid residues of the Lipase enzyme, which was also supported by the XPS analysis. Therefore, L-AgNCs conjugate represented a novel Lipase preparation technique with attributes of high activity and stability that could be an attractive choice in diverse applications ranging from catalysis to diagnostics. The overall study proposed an innovative strategy to improve enzyme stability and catalytic activity.