An enzymatic assay with formate oxidase for point‐of‐care diagnosis of methanol poisoning

Abstract

Gas chromatographic analysis for quantification of plasma methanol requires laboratory equipment and personnel, and it is typically unavailable in short time notice, especially in low-and middle-income countries. Detection of formate with the enzyme formate oxidase (FOX) is a promising method that can make the diagnosis of methanol poisoning simple and fast. The aims of this study were to test the sensitivity and specificity of a modified FOX-enzyme and to test the specificity of a point-of-care (POC)-model containing FOXenzyme with samples from patients with metabolic acidosis. The sensitivity and specificity of FOX-enzyme in aqueous solution were evaluated with a spectrometer and by visual detection for colour change. Formate concentrations between 1 and 20 mmol/L were used to test sensitivity, and 18 potentially interfering substances were tested for specificity. The sensitivity of the FOXenzyme was 100% and the specificity 97%. When specificity of the POC-model was tested, no false positives were detected. As such, the sensitivity and specificity of this modified FOX-enzyme for detection of formate were high. The results with this enzyme confirm the potential for its use in formate analysis as a fast diagnosis of methanol poisoning. K E Y W O R D S bedside testing, diagnosis, formate, methanol poisoning, point-of-care-testing

Mechanistic insights into the conversion of flavin adenine dinucleotide (FAD) to 8-formyl FAD in formate oxidase: a combined experimental and in-silico study

“…Furthermore, during the catalytic cycle, the flavin cofactor in FOx is reduced to hydroquinone, a form recently shown to be a highly controllable and effective radical source for light-driven enzyme-catalyzed reversible addition-fragmentation chain transfer (RAFT) polymerization. The high turnover rate of FOx holds promise for its extensive application in industrial biocatalysis (Heath and Turner 2022 ; Lao et al 2022 ; Tao et al 2024 ).…”