Analytical methods
The optical density at 600 nm (OD600) was measured using a spectrophotometer. ATP, APS, and PAPS were quantified by high-performance liquid chromatography (HPLC). The analysis was performed with an HPLC system equipped with an polyamine column (YMC-Pack PolyamineⅡ, 250 mm×4.6 mm) and 0.7 mM of KH2PO4 as the mobile phase. The flow rate of the mobile phase was 0.6 mL/min and oven temperature was maintained at 30℃ throughout the operation with an UV detector at 254 nm. Meanwhile, the product APS and PAPS were also analyzed by ESI-MS and the molecular weight was in accordance with that of standard.
More materials and methods are shown in Supporting Information.