Lectin Affinity Chromatography (LAC)

Many proteins are glycosylated, that is to say they have bound sugars or glycans. Glycosylation is a non-template-driven posttranslation modification. It is now known that correct glycosylation is essential for the correct folding, solubility, stability, and immunogenicity of proteins. Here, we describe the technique of Lectin Affinity Chromatography (LAC), a procedure that has the ability to separate different glycans which are attached to proteins or lipids, termed glycoproteins or glycolipids, respectively. This method utilizes different immobilized lectins that have affinity for specific sugar substrates, to separate a wide range of glycan-attached complexes (Ambrosi et al., Org Biomol Chem 3:1593-1608, 2005). To further enhance the specificity of LAC, a corresponding free sugar may be used to produce a specific elution. In general, the conditions under which lectin affinity chromatography operates are relatively mild resulting in good biological recoveries of the glycoproteins.