Hi Tom, Are your protein or related proteins known to dimerise?
Is the dimer perhaps the natural state, and are the high oligomers non-specific aggregation? That would be my first guess, knowing nothing about the protein you are working on. If you are absolutely certain that the protein should be a monomer, do you have any free cys residues you could mutate or reduce with TCEP to split a disulphide linked dimer? Just some thoughts, Dave On 27 Feb 2014 07:57, "Tom Wong" <[email protected]> wrote: > Hello everyone! > > I have run into a problem in a 55kD recombinant human protein > crystallization (expressed in E.Coil). The purity is pretty good. However, > it behaves as high oligomers in the buffer with 300mM NaCl and behaves as > dimers with a little high oligomers in the buffer with 2000mM (2M) NaCl. > I have already performed several screenings and tried several types of > buffer, salt or different pHs, etc. Only very small crystals could be > detected in the dimer drops. High oligomers seem could not be crystallized > under various of conditions. > > Has anyone ever met the same problem? Could anyone give me some > suggestions? > > Thanks very much! > > > Cheers > > > --------------------------------------- > Tom Wong > Structural Lab > --------------------------------------- >
