FIGURE 15.

HPLC analysis of product formed from TyrOOH-mediated oxidation of ebselen. A, HPLC traces of ebselen (Ebs; 0.1 mm), ebselen oxide (EbsOx; 0.1 mm), a mixture of ebselen (0.1 mm) with H₂O₂ (1 mm), and photolyzed mixtures of tyrosine and ebselen (1 mm). Samples were photolyzed in the presence of rose bengal (10 μm), phosphate buffer (50 mm), and DTPA (0.1 mm) for the indicated periods of time. B, HPLC traces of tyrosine mixtures photolyzed in the presence or absence of deuterium oxide and azide ions. Before adding ebselen (final concentration, 0.1 mm), photolyzed samples were preincubated with catalase (250 units/ml) for 5 min (as indicated). All samples were prepared in phosphate buffer (50 mm, pH 7.4) containing DTPA (0.1 mm). HPLC traces were collected using the absorption detector set at 282 nm.