Dear Peter, it's a common phenomenon to create protein concentration gradients inside a protein concentrator. Simply take it all out of the concentrator, put it in a separate tube, and mix thoroughly/vortex. The 'slime' may very well redissolve and you'll a homogeneous distribution. What you describe happens a lot to us with proteins that don't precipitate and that crystallize afterwards.
Cheers Filip Van Petegem On Thu, Jul 2, 2009 at 8:53 AM, peter hudson <peter.hudson.pe...@gmail.com>wrote: > Hello all > > I am working with a small protein-protein complex. This complex express > quite well . I purify in a buffer of pH=9.0 with 150mM NaCl and 1% of > glycerol and able to concentrate upto 20 mg per ml. I have a two clones of > this protein complex. One is N-terminal His tagged and another C-terminal > His-tagged. While concentration of the N-terminal His tagged protein in > cnetricon it forms yellow color slimy deposition on the surface of membrane. > while C-terminal His tagged protein does form very highly viscous layere at > the surface of membrane but it is completly colourless.I aliquate the > concentrated protein by pippetting into different aliquate rather than > collection of whole protein by centrifugation. if i check the concentration > of the last aliqoute(which isbottommost viscous protein part) both prtoein > complex, it shows very high concentration compared to the first fraction. I > have not done DLS. > Is my both C-terminal His tagged tagged as well as N-terminal His tagged > protein are forming soluble aggregates. > > I would appreciate the help. > > Thanks in advance > > Peter > -- Filip Van Petegem, PhD Assistant Professor The University of British Columbia Dept. of Biochemistry and Molecular Biology 2350 Health Sciences Mall - Rm 2.356 Vancouver, V6T 1Z3 phone: +1 604 827 4267 email: filip.vanpete...@gmail.com http://crg.ubc.ca/VanPetegem/
