Fig 1.

Urea and elevated temperature each induce the 19-kDa GP Ecto to bind to liposomes at low pH. (A) GPΔ Ecto was cleaved with thermolysin to 19-kDa GP Ecto and incubated with liposomes in the presence of urea at pH 7.5 or pH 5.0 at 37°C for 10 min. The amount of 19-kDa GP Ecto bound to liposomes was then determined as described in Materials and Methods. The average percentage of total 19-kDa GP Ecto bound (% GP1 on beads) from duplicate samples is shown. Error bars indicate standard deviations (SD). The gels on the right are from one set of samples. (B) 19-kDa GP Ecto was incubated with liposomes at the indicated temperature and either pH 7.5 or pH 5.0, and the percentage of total 19-kDa GP Ecto bound to liposomes was measured as for panel A. Data are the averages from six to eight determinations. Error bars indicate SD. Representative gel samples are shown on the right.