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Updated: Jan 19, 2026

Mapping Metabolism: Monitoring Lactate Dehydrogenase Activity Directly in Tissue
Published on: June 21, 2018
Inhibited enzymatic reaction of crosslinked lactate oxidase through a pH-dependent mechanism
Hugo Cunha-Silva1, F Pires2, A C Dias-Cabral2
1Departmento de Química, Facultad de Ciencias, Universidad de Burgos, Plaza Misael Bañuelos s/n, 09001 Burgos, Spain.
Abstract:
Lactate oxidase (LOx), recognized to selectively catalyze the lactate oxidation in complex matrices, has been highlighted as preferable biorecognition element for the development of lactate biosensors. In a previous work, we have demonstrated that LOx crosslinking on a modified screen-printed electrode results in a dual range lactate biosensor, with one of the analysis linear range (4 to 50 mM) compatible with lactate sweat levels. It was advanced that such behavior results from an atypical substrate inhibition process. To understand such inhibition phenomena, this work relies in the study of LOx structure when submitted to increased substrate concentrations. The results found by fluorescence spectroscopy and dynamic light scattering of LOx solutions, evidenced conformational changes of the enzyme, occurring in presence of inhibitory substrate concentrations. Therefore, the inhibition behavior found at the biosensor, is an outcome of LOx structural alterations as result of a pH-dependent mechanism promoted at high substrate concentrations.
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