Figure 2.

Laboratory-isolated starch granules were incubated with thermolysin at the Ca²⁺ levels indicated (lanes 5–9). Lane 1 is a control with no additions. Lanes 2 through 9 each contained 0.1% thermolysin; however, in lane 2, starch granules were washed with 5 mm EDTA prior to the addition of thermolysin. In lane 3, starch granules were incubated with thermolysin in the presence of 5 mm EDTA. Lane 4 is a zero-time control containing thermolysin, but with both EDTA and Ca²⁺ omitted. Lanes 5 through 9 contained Ca²⁺ at the levels indicated with EDTA omitted. Proteins remaining associated with the starch granules were then extracted and analyzed by SDS-PAGE.