We demonstrate that this expression system can be used to measure weak protein–glycan and protein–protein interactions using several well-established membrane and secreted proteins, including siglecs, the heparan sulfate-binding proteins FGF-1 (fibroblast growth factor 1) and BACE (β-site APP [amyloid precursor protein]-cleaving enzyme), and a pair of heterotypic junctional adhesion molecules (JAMs), JAM-B and JAM-C.