Figure 4. Arylsulfatase activity of media. A: Arylsulfatase A (ARSA) products were analyzed with western blot. ARPE-19 cells were transfected with 5 μg ARSA-FLAG and 1 μg SUMF1-FLAG, and cultured in serum-containing media for 2 h and then in serum-free media for 22 h. Loaded was 12.5% of the total sample. B: The ARS activity of ARSA-FLAG was measured using 0.4% of the total medium. C: Arylsulfatase I (ARSI) products were analyzed with western blot. Transfected were 8 μg ARSI-FLAG, 8 μg ARSI-C93S-FLAG, and 1 μg SUMF1-FLAG into ARPE-19 cells. D: The trichloroacetic acid (TCA)-induced precipitate of the medium was analyzed with western blot. E: The ARS activity of ARSI-FLAG was measured using 20% of the total medium. F: The pH dependence of ARS activities was shown. The ARS activities in B, E, and F give the means of three independent experiments. Bars indicate standard deviations.