I have the unretained fraction of glycoprotein eluted by concanavalin-A. I need to separate forms with highly branched oligosaccharides from the ones with bisected chains, what lectin can you recommend for this?
Most of the commercially available lectins are to specific terminal sugars (sialic acid, fucose, etc). Vector Labs has a nice selection already conjugated to agarose if we can figure the correct one for you.
For your experiment, you already separated N-glycans from O-glycans since ConA doesnt bind to O-glycans. That gets rid of most of the highly branched glycans right of the start. Also ConA binds to biantennary chains very weakly, so you may have already eluted the bisected chains. So the question becomes what are you looking for with this experiment? Is your next step to analyze the chains by MS or are you interested in fishing out the glycoproteins with a certain structure.
If you are looking to fish out the biantennary chains, you might try WGA or Phytolacca americana mitogen with chiotriose as a inhibitor to show specificity. However I cant say that with any certainty.
That a start at least until we get some more info from your experimenta question.