Hi, Without knowing exactly what you did, it's hard to guess however here are a few suggestions, in addition to the ideas already given by others:
a. try iodination. Simply place an iodine crystal near the drop (glue it to the cover slip using a tiny bit of grease) and let the vapors penetrate the drop gradually. Also you can add 0.1 mM of KI to the solution then add a speck of iodine - the KI will slowly transition the iodine via the KI3 complex to the protein. You have to experiment with timing - what worked for me was 1 day exposure. The crystals may or may not turn yellow - depends on your protein and on conditions. b. I am surprised that mercury derivatives did not work. Have you tried increasing amounts of ethyl mercury phosphate? c. Have you tried my favorite platinum derivative - KPt(NO2)3? You can add a LOT of this stuff - it's very mild on the protein. Artem > > > > Hey there, > > I have crystallised a protein in 30% MPD and it it gives nice native > data. However, it seems impossible to get heavy metal derivatives and > I read that MPD does chelate heavy metals. Did any of you make > similar experiences with xtals in MPD conditions? If so did you find > a good solution (introduction of selmet makes the protein ustable) > to make heavy metal derivatives? > > Best Regards > > Daniel
