Hi Norbert, are you talking about the non-enzymatic addition of sugars to proteins (e.g. glycation) or glycosylation, which is the enzymatic addition of sugars?
Anyway, as far as I know PES does not have free primary amines, so it will probably not interfere with glycation or glycosylation.
I'm talking about glycosilation of enzymes, sorry for the misspelling... So to be more exact i just want to know if the PES can modify the sugars added by the cellular machinery to enzymes so chaniging their surface and therefor maybe changing its recognition in a biotest.
Ok, chemical modification of glycosylated proteins by PES is unlikely. However, PES could be binding your protein of interest through hydrophobic interactions.