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.如近期Exertier等人（2025）的研究报道所示，与血红素结合的牙龈卟啉单胞菌（Porphyromonas gingivalis）HmuY蛋白（HmuY protein）复合物已完成还原处理；本研究通过监测423 nm波长处的吸光度衰减来追踪该自氧化反应——该波长对应还原减氧化差光谱的峰值，实验分别在5℃与20℃条件下随时间进行。实验采用搭载JASCO EHC 716型帕尔贴控温单元的JASCO V650型紫外-可见分光光度计（光程10 mm），每5秒采集一组时间点数据。针对从亚铁-HmuY-血红素向三价铁-HmuY-血红素转变对应的吸光度变化，本研究借助QtiPlot软件（https://qtiplot.com）以单指数函数进行拟合，以计算自氧化半衰期。实验原始数据、拟合计算结果及对应的指数拟合曲线均收录于Excel文件中。