Does Ammonium Sulfate Fraction of Protein and untrafiltration effect to enzyme a - (Oct/19/2006 )

Hello all,
I have extracted protein from leaves in order to measure enzyme activity but the amount of protein was quite low. From above, the concentrate protein by ammonium sulfate and ultrafiltration may be required. But I wondered that these process whether effect to the activity of emzyme. Please do me a favor give some advices. Thank you so much.

ammonium sulphate precipitation is a well accepted method of non-denaturizing precipitation of proteins; moreover, you lose bulk proteins if you optimize between specific precipitation and total amount of precipitated protein;

ultrafiltration has the disadvantage that it ttakes some time; even with cooling, specific but not total enzyme activity may rise; for technical reasons I have no good experience with ultrafiltartion; better use biochromatographical methods

With each purification step you will lose some specific enzyme activity, so diminish the number of purification steps

Thank you so much Kosmodom for your kind advice.