Hi, I assume Se-Met is not possible for your protein? You don't say how well (or poorly) your native crystals diffract. Increasing number of people are getting their phases by S SAD. With such affinity to high NaCl concentrations, you could also try high salt (NaCl, NaBr, RbBr etc,) soaks for phasing. Good luck, Nukri
Ruslan Sanishvili (Nukri), Ph.D. GM/CA-CAT, Bld. 436, D007 Biosciences Division, ANL 9700 S. Cass Ave. Argonne, IL 60439 Tel: (630)252-0665 Fax: (630)252-0667 [EMAIL PROTECTED] -----Original Message----- From: CCP4 bulletin board [mailto:[EMAIL PROTECTED] On Behalf Of Priyank Maindola Sent: Thursday, June 28, 2007 12:28 PM To: [email protected] Subject: [ccp4bb] heavyatom soaking problem Hello all, I am struggling with getting the phases out for my protein. Heavyatom database shows that only mercury and samarium have the binding motifs in it. Sodium iodide soak is killing the crystal even as less as 0.2 Molar concentration for 30sec. With Potassium iodide crystal is okay upto 0.75M for 1 & a half min but the incorporation is not at relevent sites.(Iodide signal is not distinct and is weak) Hg & Au salts precipitate it. With Pt signal is weak. Somewhere I read that high salt causes problems for heavy atom to bind to protein.My protein needs high salt for stability (750mM NaCl) Please help with some suggestion!!
