you can derivatize the protein before crystallization. By mass you can check the amount as most derviatives bind covalent. Moreover you can remove metal that doesn't bind.
Best of luck Kornelius On Tue, 17 Apr 2007 13:49:33 -0400 [EMAIL PROTECTED] wrote: > 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 > > ---------------------------------------------- Kornelius Zeth Max Planck Institute for Developmental Biology Dept. Protein Evolution Spemannstr. 35 72076 Tuebingen, Germany [EMAIL PROTECTED] Tel -49 7071 601 323 Fax -49 7071 601 349
