Hi Greg,
I am not sure why you are so surprised! If the zinc is altering the
conformation and/or folding of your protein, this might change the
accessibility of trypsin cleavage sites, thus changing your limited
proteolysis pattern.
Eg:
Metal-ion induced conformational changes in alkaline phosph
To add more information:
The proteolysis buffer was 50 mM Tris / HCl pH 8.0, 150 mM NaCl, 0.5 mM ZnCl
and 0.1 mM TCEP; protein concentration was ~ 25 µM. Proteolysis was carried
out at 4°C over 2 hours.
Thank you very much for the literature, Mark - I'll look into it.
Greg
2011/3/16 Matthias
Dear all,
I was working with a protein which is known to bind zinc. I tried to make a
limited proteolysis (with trypsin) after purification (metal affinity, ion
exchange and gel filtration; last step uses EDTA to remove bound metal ions)
in the presence and absence of zinc ions and I was quite sur
