Figure 4.

Ion exchange chromatography of [³⁵S]sulfate-labeled PRPg2. Secreted PRPg2 labeled as described in Figure 3 was loaded onto a DEAE (DE 52) cellulose column and eluted with a 0.05 M to 0.6 M NaCl gradient as described in MATERIALS AND METHODS. Equal amounts of each fraction were analyzed by SDS-PAGE, and [³⁵S]sulfate-labeled PRPg2 was quantitated by phosphorimager analysis. •, PRPg2 expressed alone; ○, PRPg2 coexpressed with basic PRP.