Chondroitin Sulfate Proteoglycans Are De Facto Cellular Receptors for Human Papillomavirus 16 under High Serum Conditions

And these are the different potential sulfation sites within these different disaccharides. There are six S sites that are the same, and two S sites that could be the same. However, heparin sulfate has an additional 23 S sites, and as I mentioned before, conjoined sulfate also has a four S site. These sites are important because they introduce different binding properties to the polysaccharide, resulting in different molecules. Although they have a similar structure and perform similar functions, they also have a similar parallel biosynthesis pathway diagram. We won't go into detail here, but this diagram illustrates the numerous enzymes involved in the synthesis of heparin sulfate and chondroitin sulfate.