By expressing a recombinant form of the N-terminal domain I of the protein and demonstrating that digestion of the peptide with either heparanase or chondroitinase did not lead to complete loss of the peptide's activity, it was shown that chondroitin sulfate chains can be added to human perlecan.
Researchers showed that adding chondroitin sulfate chains to human perlecan is possible by expressing a recombinant form of the N-terminal domain I of the protein and demonstrating that digestion with heparanase or chondroitinase did not completely destroy the peptide's activity.