Porphyromonas gingivalis HmuY autooxidation

Porphyromonas gingivalis HmuY protein in complex with heme was reduced, as reported recently (Exertier et al. 2025), and the autoxidation reaction was followed by monitoring the absorbance decrease at 423 nm, which corresponds to a maximum in the reduced-minus-oxidized difference spectrum, monitored at 5°C and 20°C over time. Time points were collected every 5 s using a JASCO V650 UV–visible spectrophotometer (10 mm light path) equipped with a JASCO EHC 716 Peltier unit. The variation in absorbance corresponding to the transition from ferrous to ferric HmuY-heme was fitted as a single exponential function using the QtiPlot software (https://qtiplot.com) to determine autoxidation half-times. Experimental data, calculations, and corresponding exponential fits are shown in the Excel files.