Fig. 5.
AL-I-NOH sulfonation by human SULTs. AL-I-NOH (0.5–50 μM) was incubated for 1–30min with each of the following enzymes, (A) SULT1B1, (B) SULT1A1 and (C) SULT1A2 in the presence of PAPS. Time course of AL-I-N-OSO3H formation was monitored by Time of Flight LC/MS. Initial rates were calculated using linear regression analysis in Sigma Plot and plotted against dose of AL-I-NOH. Product formation was linear up to 20min. Results are shown as mean values with standard deviations for at least three independent experiments. (D) Kinetic parameters of human SULTs with AL-I-NOH as a substrate. Apparent kinetic parameters were obtained by fitting curves to Michaelis–Menten equation.