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A DORFMAN

Publications and source records attributed to A DORFMAN.

At least 19 recordsLinked to original sources
PubMed1964

METABOLISM OF ACID MUCOPOLYSACCHARIDES.

The biosynthesis of the acid mucopolysaccharides, hyaluronic acid and chondroitin sulfuric acid, occurs by way of uridine nucleotides which contain the monosaccharide units of the respective polysaccharides. The mechanism of alternation of groups is as yet unknown. Certain of the acid mucopolysaccharides are covalently bound to protein by way of serine. In the case of the protein-polysaccharide complex of cartilage, there is evidence to suggest that the polysaccharide may be linked to the serine by way of galactose. Chondroitin sulfuric acid B may be isolated almost free of amino acids from the tissues and urine of patients with the Hurler syndrome without the use of proteolytic enzymes, acid, or alkali. This contrasts markedly with the tight binding of this compound to protein in normal tissue. It is suggested that the metabolic defect in this disease may reside in a defect of the peptide or linkage of the peptide to polysaccharide resulting in failure of the acid mucopolysaccharide to be fixed normally in connective tissue. Such a defect may result in interference with normal regulation of polysaccharide synthesis with a resultant increased synthesis. It is proposed that such a mechanism may obtain in other heritable connective tissue diseases as well as other storage diseases.

Carbohydrate Metabolism↗
PubMed1963

The occurrence of intracellular chondroitin sulfate.

Suspensions of chondrocytes were prepared by treatment with trypsin of the epiphyses of tibias and femurs of 13-day-old chick embryos. After washing to remove the matrix, such suspensions readily incorporate radioactive sulfate into both intracellular and extracellular chondroitin sulfate. Following disruption of the cells, the cell constituents were fractionated by centrifugation. Fractions obtained from cells incubated for 10 minutes showed a concentration of radioactivity in the material which sediments at 10,000 to 20,000 g. At this time the radioactivity of the extracellular chondroitin sulfate is low, but at 1 hour the radioactivity of the intracellular material is relatively unchanged, while that of the extracellular polysaccharide is markedly increased. Following incubation of the chondrocyte suspensions in a tissue culture medium, the intracellular chondroitin sulfate was isolated. This was compared with chondroitin sulfate isolated from the cartilage matrix. Chemical analysis and infrared spectroscopy indicated that both the intracellular and extracellular polysaccharides consist of a mixture of chondroitin sulfuric acids A and C. A portion of the chondroitin sulfate is not sulfated.

Animals↗