Afshan Begum wrote:
Dear All,
I have a severe prob lam to performed my ligand binding study with
corresponding protein. I have taking the native diffraction data at
1.75 A and after that i have performed soaking as well
co-crystallization experiment with my inhibitors.
Problem is that at the active site phosphate ion always bind instead
of inhibitors. I have used 1.6 M ammonium phosphate conc at the
crystallization recipe which is a very weak inhibitor of my protein
whereas the ligand is already clinically applicable but due to the
very high conc. of phosphate i have not achieved my target. If some
one can suggest me what else i can replace with ammonium phosphate or
any other suggestions would be appreciated.
I have tried to grown crystals some other condition but the crystal
was not diffracted beyond 3.5 A.
Best Regards
AFSHAN
I think you could get some hints from the following publication, J.
Appl. Cryst. (1988) 21, 426. The transfer of protein crystals from their
original mother liquor to a solution with a completely different
precipitant, Schreuder H et al.
http://scripts.iucr.org/cgi-bin/paper?ms0234
The aim would then be to (try to) transfer your crystals to another
mother liquor that does not contain any phosphate.
HTH,
Fred.
