Characterization of Sulfated Glycoconjugates in Human Gastric Mucosa

Radiolabeled glycoconjugates were prepared by incorporation of [35S]sulfate and [3H]glucosamine into the gastric mucosa of human gastric resection specimens, using organ culture techniques. Specimens which incorporated higher amounts of [35S]sulfate into high molecular glycoconjugates (Fr-1) were designated as group I. The average specific activity in Fr-1 of group I was 30 times that of group II, but the glucosamine uptake remained about the same in all cases. All specimens in group I were positive to intestinal metaplasia in their adjacent mucosal area. The sulfated glycoproteins in Fr-1 of group I were found to incorporate 80% of the 35S and the remaining 20% by sulfated glycosaminoglycans. But the glycoconjugates constituting all the Fr-1 of group II were identified as glycoproteins and incorporating 35S only to a small extent were identified as sulfated glycoproteins. The susceptibility of the glycoproteins from group I mucosa to pronase digestion was different from that of group II. The glycoproteins synthesized in group I mucosa were as sulfated glycoproteins as well as nonsulfated glycoproteins and glycosaminoglycans, while the group II glycoproteins consisted primarily of nonsulfated glycoproteins.