Fig 6.

Cathepsin cleavage of GPΔ Ecto to 19 kDa is necessary for optimal liposome binding. (A) GPΔEcto (Δ, lane 1) was digested with Cat L (20 kDa, lane 2) or thermolysin (19 kDa, lane 3), separated on an SDS–15% polyacrylamide gel, and analyzed by Western blotting for GP1. (B) Uncleaved GPΔ Ecto, 20-kDa GP Ecto, and 19-kDa GP Ecto were incubated as indicated. Liposome binding was then assessed as described in the legend to Fig. 1. (C) The 20-kDa GP Ecto was incubated with liposomes at pH 5.0 for 5 min at either 50°C or 60°C, and binding was measured as for panel B. Data are the averages from duplicate samples. Error bars indicate SD.