Synthesis of chondroitin sulfate oligosaccharides using enzymatic reconstruction

Glycosaminoglycan (GAG) has many kinds of structural domains, and is known to participate in physiological functions such as anticoagulation and antithrombotic activities. It is important to prepare GAG oligosaccharides as investigation models in order to analyze their relationship between structure and function. In this review, I describe the methods of synthesis for the reconstruction of chondroitin sulfate oligosaccharides using testicular hyaluronidase, which is an endo-beta -N-acetylhexosaminidase. The reaction occurs with changing combinations of chondroitin (Ch), chondroitin 4-sulfate (Ch4S), chondroitin 6-sulfate (Ch6S) and the other GAGs as an acceptor and a donor of transglycosylation, which reconstructs the sugar chain. Thus, it is possible to custom-synthesize oligosaccharides by controlling their combinations (Fig. 1). Therefore, it was possible to prepare many libraries of chondroitin sulfate oligosaccharides including chimeric unnatural GAGs. I expect that these libraries will contribute to new developments in glycotechnology in the future.