Dear Shiva, It has happened many times. This paper (not about crystallography) is one example: http://onlinelibrary.wiley.com/doi/10.1111/j.1742-4658.2005.05047.x/abstract;jsessionid=864D79CC1089210C6A3CDDAC3AFE25DB.d03t04
Why don't you try SEC with high salt concentration? Yours, Clement On Jun 9, 2011, at 3:19 AM, Shiva Bhowmik wrote: > Dear All, > > I am working on a protein structure that yielded comparable diffraction > quality crystals from two different crystallization condition. One of the > crystallization condition conatins high conc. of salt pptant whereas the > oher one contains high conc. of organic pptant. There are some minor > differences in the stucture with respect to the backbone but what most > surprising is the oligomeric structure. AnSEC study suggest the protein to be > a tetramer in solution and a tetrameric assembly is observed in the > asymmetric unit of the space group of the crystal obtained from high conc. of > organic pptant. However, the crystal structure from the high conc. of salt > pptant does not reveal any oligomeric assembly - symmetry operations of the > space group does not suggest any oligomeric assembly. I believe the high salt > conc. disrupted the tetrameric assembly and enabled crystallization of the > protein as a monomer. > > Curious to know if there has been any similar precedence before. > > Cheers, > > Shiva #################################################### Clement Angkawidjaja, PhD. G30 Assistant Professor ------------------------------------------------------------------------------------------- Chemistry-Biology Combined Major Program International College, Osaka University 1-30 Machikaneyama-cho Toyonaka, Osaka 560-0043, Japan http://cmp.sci.osaka-u.ac.jp/CMP/ Tel. +81-6-6850-5952 Fax +81-6-6850-5961 ------------------------------------------------------------------------------------------- Laboratory of Molecular Biotechnology Graduate School of Engineering Osaka University 2-1 Yamadaoka U1E-804 Suita, Osaka 565-0871, japan http://www.mls.eng.osaka-u.ac.jp/~bio_ext/mlsbe123/clement.html Tel/Fax +81-6-6879-4157 ####################################################
