Abstract
Glycosylation is a ubiquitous post-translational modification that decorates proteins and lipids with glycans. These glycans can play critical roles in regulating biological events, and therefore, the discovery of strategies that target these molecules represent an important advancement toward understanding and controlling glycan-mediated cellular phenotypes. We describe the use of a small molecule, surfen, to temporarily silence the functions mediated by heparan sulfate glycosaminoglycans in mouse embryonic stem cells. Surfen binds heparan sulfate to antagonize growth factor interactions, thereby inhibiting signal transduction events that lead to differentiation. The strategies outlined in this chapter allow the characterization of resulting antagonistic effects caused by glycan-small molecule binding events toward maintaining embryonic stem cell pluripotency, curbing differentiation, and inhibiting signaling events.