FIGURE 7.

N^α-terminal acetylation did not affect initial peroxidase activity. A, peroxidase activities of hPrx II and rPrx II were monitored by NADPH oxidation in the presence of thioredoxin system (see “Experimental Procedures”). An initial linear portion of the absorbance change (10 s) was used for the calculation of these activities. The results shown are the means of three independent assays. Samples from the assay mixtures were taken out 150 s after the reaction start and subjected to two-dimensional PAGE (B) and SDS-PAGE (C) analysis to identify and quantitate C_P-SO₃H, respectively. Immunoblots were visualized by anti-Prx II and anti-C_P-SO₃H antisera. r, rPrx II; h, hPrx II. D, graphical representation of the Tsa1p-SO₃H immunoblot signal of C. The band intensities were quantitated by a densitometer (Gel Doc XR system, Bio-Rad).