Studies on corneal polysaccharides. IV. Chromatography of corneal glycosaminoglycans on ECTEOLA cellulose using formate buffers as eluting solvents

Articular cartilage, blood serum glycosaminoglycans and glycoproteins in osteoarthritis deformans

Glycosaminoglycans in articular cartilage from human femoral heads have been isolated and fractionated by means of a cellulose microscale technique. The glucosaminoglycans have been identified by different procedures as keratan sulphate, hyaluronic acid, heparitin sulphate, chondroitin 4-sulphate, chondroitin 6-sulphate and dermatan sulphate. Osteoarthritic cartilage showed a significant reduction of dermatan sulphate, chondroitin 6-sulphate, keratan sulphate and heparitin sulphate. The content of glycoprotein carbohydrate components in the cartilage (neuraminic acid derivatives, hexoses, 6-deoxyhexoses) also appeared to be reduced. It has been shown that chondroitin 4-sulphate, keratan sulphate and dermatan sulphate content was considerably increased in osteoarthritic serum. Among serum glycoprotein carbohydrate constituents only the content of 6-deoxyhexoses was slightly increased.

Water vapor sorption of keratan sulfate

Keratan sulfate was isolated from bovine cornea. The water vapor sorption isotherms were obtained on both sodium and calcium salts of keratan sulfate at different temperatures. Deuterated water sorption isotherms were obtained on sodium keratan sulfates. The infrared spectra of the keratan-sulfate was monitored as a function of water and D2O uptake. The results are discussed in terms of an open polymer matrix that exists in the solid state of keratan sulfate.

The biosynthesis in vitro of keratan sulphate in bovine cornea

1. Bovine corneas were incubated in vitro with [U-(14)C]glucose. 2. The glycosaminoglycans of corneal stroma were isolated and fractionated on cetylpyridinium chloride-cellulose columns. The major components were keratan sulphate (71%), chondroitin 4-sulphate (17%) and chondroitin 6-sulphate (4%). 3. The acid-soluble nucleotides and intermediates of glycosaminoglycan biosynthesis of corneal stroma were separated on Dowex 1 (formate form) and the tissue content and cellular concentrations were determined. 4. The rates of synthesis of the intermediates of glycosaminoglycan biosynthesis in corneal stroma were determined. 5. The incorporation of radioactivity from [U-(14)C]glucose into the uronic acid and hexosamine components of the glycosaminoglycans present in corneal stroma were measured and the turnover rates of these polymers were calculated. It was found that keratan sulphate was turning over in about 723h and chondroitin 6-sulphate in 251h.