Fig. 6. Heparin-binding properties of cathepsin E. Recombinant cathepsin E was subjected to affinity chromatography on a heparin-Sepharose column, eluted with stepwise increasing concentrations of NaCl in PBS buffer of pH 6.0 (A) or pH 7.4 (B). For every NaCl concentration, four fractions containing 100 µl were collected and 30 µl from each fraction was subjected to western-blot analysis using an antibody specific for cathepsin E. dim, dimeric cathepsin E; FT, flow-through fraction; mon, monomeric cathepsin E.