Rapid and Oriented Immobilization of Laccases on Electrodes via a Methionine-Rich Peptide
Haiyang Cui, Lingling Zhang*, Dominik Söder, Xiaomei Tang, Mehdi D. Davari, and Ulrich Schwaneberg*. ACS Catalysis, 2021. 11, 4, 2445-2453.
MetRich is a valuable binding motif for the rapid immobilization and high performance of laccases and other oxidoreductases in bioelectrocatalytic applications.
Nowadays, enzymatic bioelectrocatalysis has found wide applications ranging from electrochemical biosensing platforms, implantable enzymatic fuel cells, to bioelectrosynthetic reactors. Nonetheless, insufficient electron-transfer rates and long-term instabilities of enzyme electrodes are still challenging issues. Herein, we reveal that MetRich (methionine-rich segment) plays an important role in rapid immobilization of copper efflux oxidase (CueO from Escherichia coli) on electrodes by studying the adsorption and bioelectrocatalysis behavior of CueO, a truncated CueO (ΔMetRich CueO), and a serine-rich substituted CueO (SerRich CueO). Atomic molecular dynamics (MD) simulations demonstrate that the synergistic effect of π–π stacking and hydrophobic interactions contribute to the high affinity of MetRich to carbon nanotubes (CNT). To demonstrate the broad applicability, MetRich was also fused to spore coat protein A (CotA), another bacterial laccase from Bacillus licheniformics. It is known that the T1 Cu active site of CotA is around the C-terminus and the entry site of electrons in the laccase-catalyzed oxygen reduction. Fusion of MetRich to the C-terminus of CotA is found to endow CotA with the properties of rapid and oriented adsorption at the electrode surface, “draws” the T1 Cu active site close to the CNT electrode, and thereby increases the electron-transfer rate. The finding and validation make MetRich a valuable binding motif for the rapid immobilization and high performance of laccases and perhaps other oxidoreductases in bioelectrocatalytic applications.
L. Zhang acknowledges the support from the Alexander von Humboldt Foundation. Haiyang Cui is financially supported by the China Scholarship Council (CSC) scholarship. This work was realized in the division Hybrid Catalysis and High Throughput Screening and was supported by division Computational Biology and computing resources granted by JARA-HPC from RWTH Aachen University (JARA0169 and JARA0187).
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Cui, H.; Zhang, L.*; Söder, D.; Tang, X. M.; Davari, M. D.; Schwaneberg, U.*, Rapid and oriented immobilization of laccases on electrodes via a methionine-rich peptide. ACS Catalysis, 2021. 11, 4, 2445-2453. https://doi.org/10.1021/acscatal.0c05490Copyright: ACS Catalysis