Mucopolysaccharides of rabbit bone marrow cells. Identification and properties

• 1.1. Glycosaminoglycans were isolated from rabbit bone marrow cells (consisting to 90% or more of granulocytes at various stages of maturity). The largest part was identified as chondroitin 6-sulfate and a minor part was probably hyaluronic acid.
• 2.2. Among the subcellular fractions the granule fraction contained the bulk of the glycosaminoglycans. For release of the polysaccharide from the granules salt solutions were required.
• 3.3. The glycosaminoglycans and the proteins of extracts from the granule fraction were separated by equilibrium sedimentation in cesium chloride. Gel chromatography on Sephadex G-200 of the polysaccharide material before and after proteolytic digestion with papain indicated that part of it consisted of chondroitin sulfate proteoglycan while another part consisted of free chondroitin sulfate chains. Experiments where ³⁵S was injected prior to preparation of bone marrow cells demonstrated that the largest chondroitin sulfate molecules had the highest specific activity of ³⁵S, indicating a turnover of the polysaccharide in the granules.
• 4.4. Recombination of glycosaminoglycans and proteins obtained by equilibrium sedimentation in cesium chloride yielded a precipitate depending on the ionic strength and the pH of the mixture. It is suggested that the function of glycosaminoglycans in leucocytes might be to provide an acid matrix to bind and neutralize the highly cationic proteins of the granules.