Skip to main content
. Author manuscript; available in PMC: 2013 Jul 2.
Published in final edited form as: J Carbohydr Chem. 2012 Jul 2;31(4-6):325–352. doi: 10.1080/07328303.2012.676118

Figure 8.

Figure 8

Strategy to capture the in situ trans ligands of CD22. N-acetylneuraminic acid modified with an aryl azide at the C9 position (9-AAz-NeuAc) was metabolically incorporated into cellular glycoproteins. B cells deficient in sialic acid biosynthesis (BJAB K20) convert exogenously added 9-AAz-NeuAc into its CMP-activated form inside the nucleus. Upon transport into the Golgi, CMP-9-AAz-NeuAc can be utilized as a substrate by glycosyltransferases for incorporation into cell-surface glycoproteins. These 9-AAz-NeuAc-modified B cells are then overlaid onto a CHO cell monolayer expressing CD22 with a V5 tag and UV irradiated to induce photocrosslinking. Anti-V5 immunoprecipitated complexes can be immunoblotted for candidate proteins identified previously by mass spectrometry-based proteomics.