Competition kinetics for the reaction of HSA sulfenic acid with hydrogen sulfide. HSA-SOH (0.5 μm) was incubated with TNB (66 μm) and increasing concentrations of Na2S in phosphate buffer (0.1 m, pH 7.4, 0.1 mm DTPA, 25 °C). A, time courses of TNB consumption at 412 nm. B, correlation of kobs
versus concentration of Na2S.