You add various amounts of (NH₄)₂SO₄, centrifuge the precipitated protein, remove the supernatant and then resuspend and dialyze the pellet against buffer to lower the ammonium sulfate concentration below 0.1%, as too much salt may inhibit the enzyme. You assay the dialysate (from the pellet) for endonuclease activity. The results are shown in the table below:

Based on this, what ammonium sulfate cut would you use, if you wanted to maximize both yield and purity?

(e.g., A cut of 50% - 70% means that you add ammonium sulfate to 50%, get rid of what precipitates, and then add more ammonium sulfate to 70%, and collect the precipitate, throwing away what remains soluble. In other words, you collect what is soluble at 50% ammonium sulfate but insoluble at 70% ammonium sulfate.)

Your answer:

Group of answer choices

a- 10% - 40%

b- 10% - 50%

c- 10% - 80%

d- 50% - 80%

e- 40%-50%

f- There is no point using ammonium sulfate precipitation approach because your enzyme becomes inactive during this procedure.

g- There is no point using ammonium sulfate precipitation approach because your enzyme precipitates together with the rest of E. coli proteins.

[(NH4)2SO4] during precipitation Activity in dialysate of pellet (U) Proteins in dialysate of pellet (mg) 10% 8 90 20% 13 105 30% 5 120 40% 25 150 50% 870 300 60% 890 350 70% 885 390 80% 897 440