Comparative studies on proteodermatan sulfate of bovine gastrointestinal tract

Proteodermatan sulfate was extracted from four areas of the bovine gastrointestinal tract (esophagus, stomach, small intestine and colon) with 4 M guanidine-HCl and then purified by ion-exchange and gel filtration chromatography. Dermatan sulfate chains which made up proteodermatan sulfate from each area were separately prepared by Pronase P and endo-beta-xylosidase digestion. The properties of the proteodermatan sulfate and dermatan sulfate chains were compared using electrophoresis and high-performance liquid chromatography. The molecular size of proteodermatan sulfate purified from each area was estimated to be greater than 8 x 10(5), and the molecular sizes of dermatan sulfate chains from esophagus, stomach, small intestine, and colon were 27,000, 24,500, 21,000, and 21,500, respectively. The dermatan sulfate chains from the esophagus were slightly undersulfated in comparison with the others. These results show that the molecular sizes of proteodermatan sulfate from different regions of the gastrointestinal tract are similar to each other, but are larger than those from other tissues. Dermatan sulfate chains differed from each other to a slight degree with respect to chain length and sulfation, that from the esophagus being the largest. These differences in proteodermatan sulfate structure seem to reflect the organ specificities of the gastrointestinal tract.