Intracellular distribution and sites of synthesis of glycosaminoglycans (mucopolysaccharides) in human leukocytes

The content of chondroitin sulfate was measured in leukocyte subcellular fractions prepared by differential centrifugation and density gradient centrifugation. The granule fraction contained the bulk of chondroitin sulfate while the microsomal fraction contained only small amounts of this polysaccharide.The biosynthesis of chondroitin sulfate was localized to microsomal structures since these exhibited the highest specific activity after incubation of the cells with ³⁵S-sulfate and ¹⁴C-glucosamine.The occurrence in the leukocyte granules of ionic interactions between chondroitin sulfate and other substances is indicated as NaCl of high ionic strength was needed for release from the granules of the polysaccharide.