An engineered lactate oxidase based electrochemical sensor for continuous detection of biomarker lactic acid in human sweat and serum.

Autor:	He Q; Department of Biomedical Engineering, University of Houston, United States., Wang C; Department of Biomedical Engineering, University of Houston, United States., Jain R; Biomolecular Structure and Integration of Sensors (BioSIS) Program, Department of Nutrition, School of Medicine, Case Western Reserve University, United States.; Center for Proteomics and Bioinformatics, School of Medicine, Case Western Reserve University, United States.; Center for Synchrotron Biosciences, School of Medicine, Case Western Reserve University, United States., Byrnes J; National Synchrotron Light Source II, Brookhaven National Laboratory, United States., Farquhar ER; Biomolecular Structure and Integration of Sensors (BioSIS) Program, Department of Nutrition, School of Medicine, Case Western Reserve University, United States.; Center for Synchrotron Biosciences, School of Medicine, Case Western Reserve University, United States., Reed E; Biomolecular Structure and Integration of Sensors (BioSIS) Program, Department of Nutrition, School of Medicine, Case Western Reserve University, United States.; Sensate Biosystems LLC, Cleveland, OH, United States., Berezovsky E; Biomolecular Structure and Integration of Sensors (BioSIS) Program, Department of Nutrition, School of Medicine, Case Western Reserve University, United States.; Sensate Biosystems LLC, Cleveland, OH, United States., Chance MR; Biomolecular Structure and Integration of Sensors (BioSIS) Program, Department of Nutrition, School of Medicine, Case Western Reserve University, United States.; Center for Proteomics and Bioinformatics, School of Medicine, Case Western Reserve University, United States.; Center for Synchrotron Biosciences, School of Medicine, Case Western Reserve University, United States.; Sensate Biosystems LLC, Cleveland, OH, United States., Lodowski D; Biomolecular Structure and Integration of Sensors (BioSIS) Program, Department of Nutrition, School of Medicine, Case Western Reserve University, United States.; Center for Proteomics and Bioinformatics, School of Medicine, Case Western Reserve University, United States.; Sensate Biosystems LLC, Cleveland, OH, United States., An R; Department of Biomedical Engineering, University of Houston, United States.; Biomolecular Structure and Integration of Sensors (BioSIS) Program, Department of Nutrition, School of Medicine, Case Western Reserve University, United States.; Department of Biomedical Sciences, University of Houston, United States.
Jazyk:	angličtina
Zdroj:	Heliyon [Heliyon] 2024 Jul 09; Vol. 10 (14), pp. e34301. Date of Electronic Publication: 2024 Jul 09 (Print Publication: 2024).
DOI:	10.1016/j.heliyon.2024.e34301
Abstrakt:	Lactate levels in humans reveal intensity and duration of exertion and provide a critical readout for the severity of life-threatening illnesses such as pediatric sepsis. Using the lactate oxidase enzyme (Lox) from Aerococcus viridians , we demonstrated its functionality for lactate electrochemical sensing in physiological fluids in a lab setting. The structure and dynamics of LOx were validated by crystallography, X-ray scattering, and hydroxyl radical protein footprinting. This provided a validated protein template for understanding and designing an enzyme-based electrochemical sensing elements. Using this template, LOx enzyme variants were generated and compared. Comparison of the variants demonstrates that one exhibits effective lactate sensing at significantly reduced operating voltages. Additionally, we demonstrate that the four hexahistidine-tags on each enzyme tetramer are sufficient for immobilization to create a durable, functional sensor, with no need for a covalent attachment, enabling self-immobilization and eliminating the need for additional immobilization steps. The functionality of the LOx enzyme variants was verified at physiological lactate concentrations in both human serum (0-4 mM) and artificial sweat (0-100 mM) using 3-electrode setups for analysis of the three variants in parallel. Accuracy of measurement in both artificial sweat and human serum were high. Employing a microfluidic flow cell, we successfully monitored varying lactate levels in physiological fluids continuously over a 2h period. Overall, this optimized LOx enzyme, which self-immobilizes onto gold sensing electrodes, facilitates efficient and reliable lactate detection and continuous monitoring at reduced operating voltages suitable for further development towards commercial use. Competing Interests: The authors disclose that a provisional patent application related to the findings of this paper has been filed by Ran An, David Lodowski, and Mark Chance. (© 2024 Published by Elsevier Ltd.)
Databáze:	MEDLINE
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