4 replies to this topic

[arctos]

Dera folks
Can TCA and aceton percipitate glycoprotein? The proteins including glycoproteins are in 15% sugar solution. I want to isolate the total protein.
And did anyone use the total glycoprotein isolation kit from Qiagen. Is it efficient or not. I am worried about the sugar in the solution might interfere the glycoprotein binding onto the immobilized lectin. Any suggestions?

[K.B.]

It should work, although I don't know how would sugar behave. Add TCA to sugar solution (without protein) to see what happens.

I don't know what principle this kit is based on - if it's lectin based, sugar in solution may interfere. Kit manual should give you acceptable limits of additives in sample. Anyway, it's not a problem - you may simply dialyse your sample to remove sugar.

[mdfenko]

sugar makes the solution dense so it will be difficult to pellet the precipitate. as recommended by k.b., you should dialyze the solution.

[arctos]

Thank you for your replies. I tried dialyze the solution. As the protein conc. is only 20ug/ml and mostly are glycoprotein, they could bind onto semi-permeable membrane. I lost a lot. Do you think whether pretreating the  membrane with tween 80 can save  a little or not?

[mdfenko]

adding salt (0.15-0.2M) to the solution should prevent binding to the membrane.