FIG. 4.

Biochemical membrane association of AH-GFP and cytochrome b5 proteins to trypsin-treated Huh7-derived membranes. (a and b) Isolated Huh7-derived membranes were either mock treated or treated with 0.1% trypsin on ice for 30 min before the addition of 0.1% soybean trypsin inhibitor. The in vitro-translated AH-GFP and cytochrome b5 proteins were incubated with either the mock-treated or the trypsin-treated Huh7 membranes and were subjected to membrane flotation assays as described for Fig. 1. (c) Membrane association of the proteins determined in three independent experiments was quantified by phosphorimager analysis and plotted. Note that in contrast to that of cytochrome b5, the amount of the membrane-bound AH-GFP was decreased when the trypsin-treated membrane was used.