Contribution to study the glycoprotein ligands of the cerebellar soluble lectin in human K562 tumour cells

Abstract

Many cancer cells over-express significantly the glycoproteins specific to the endogenous cerebellar soluble lectin or CSL. These ligands may present the same electrophoretic profiles regardless of the specie or tissue. We purified a large amount of the active CSL using an immuno-affinity chromatography, which was used to isolate the CSL ligands from human tumour K562 cell lines. After protease digestion of these ligands, we analyzed the obtained peptides using reverse phase chromatography and isolated an overrepresented group that carried N-glycans and was relatively hydrophobic. Thus, we suggested that the CSL ligands have a common pepetide sequence specifically recognized by the CSL, who could direct the production of these CSL-recognized N-glycans. Moreover, we speculated that the expression deregulation of a specific exon encoding this peptide sequence alters the glycosylation in K562 tumour cells.