|About this Abstract
||MS&T23: Materials Science & Technology
||Advanced Ceramics for Environmental Remediation
||Copper Oxide Nanoparticles as a Metal Ion Source for Enhanced Catalytic Stability of Laccase
||Olivia A. Graeve, F. Javier Suarez, Sergio Ojeda Santillán, Rafael Vazquez-Duhalt
|On-Site Speaker (Planned)
||Olivia A. Graeve
In this study, we describe a two-fold improvement in the catalytic rate (<i>k</i><sub>cat</sub>) of laccase immobilized on CuO nanoparticles. Specifically, laccase from <i>Coreolopsis gallica</i> was covalently immobilized into CuO nanoparticle surfaces, achieving complete coverage of the surfaces as determined from transmission electron microscopy. The affinity constant (<i>K</i><sub>M</sub>) during the catalysis process was not significantly affected. Interestingly, the total turnover number of the laccase-coated CuO nanoparticles reached 358 x 10<sup>6</sup> mol ABTS/mol laccase, which is four times higher than the free enzyme (88 x 10<sup>6</sup>). Inductively coupled plasma mass spectrometry was used to determine the loss of copper ions from free laccase during the catalytic cycle, suggesting this as the origin of enzyme inactivation. This work contributes to an improved understanding of the laccase-CuO interface and confirms that CuO nanoparticles are appropriate sources for copper ion replacement in laccase during the catalytic cycle, for potential applications in biocatalysis and environmental remediation.