Remodeling of heparan sulfate by cell surface enzymes
Heparan sulfate (HS) present on cell surfaces may be remodeled by extracellular sulfatase enzymes (Sulfs). These enzymes remove a fraction of the 6-O-sulfate groups on HS, thereby altering the manner in which the chains bind to protein partners. The loss of 6-O-sulfate groups alters cell responses to growth factors signaling through binding to HS, including Wnts, bone morphogenic proteins and fibroblastic growth factors. The question remains regarding the HS sequence context for Sulf recognition and activity, as well as the differences associated with different cellular phenotypes. We investigated remodeling of HS chains by Sulf2 at the disaccharide level. The results demonstrated that Sulf2 acts in a different manner at the chain non-reducing end, relative to the interior regions of the chain.