Carriers for enzymatic attachment of glycosaminoglycan chains to peptide.

In the previous study, we have found that the endo-beta-xylosidase from Patinopecten had the attachment activities of glycosaminoglycan (GAG) chains to peptide. As artificial carrier substrates for this reaction, synthesis of various GAG chains having the linkage region tetrasaccharide, GlcA beta 1-3Gal beta 1-3Gal beta 1-4Xyl, between GAG chain and core protein of proteoglycan was investigated. Hyaluronic acid (HA), chondroitin (Ch), chondroitin 4-sulfate (Ch4S), chondroitin 6-sulfate (Ch6S), and desulfated dermatan sulfate (desulfated DS) as donors and the 4-metylumbelliferone (MU)-labeled hexasaccharide having the linkage region tetrasaccharide at its reducing terminals (MU-hexasaccharide) as an acceptor were subjected to a transglycosylation reaction of testicular hyaluronidase. The products were analyzed by high-performance liquid chromatography and enzyme digestion, and the results indicated that HA, Ch, Ch4S, Ch6S, and desulfated DS chains elongated by the addition of disaccharide units to the nonreducing terminal of MU-hexasaccharide. It was possible to custom-synthesize various GAG chains having the linkage region tetrasaccharide as carrier substrates for enzymatic attachment of GAG chains to peptide.