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Biomedical subjects

M Schubert

Publications and source records attributed to M Schubert.

At least 199 records · Page 11Linked to original sources
PubMed1970

The interaction of monosodium urate with connective tissue components.

Monosodium urate deposits almost exclusively in the connective tissues of patients with gout. Acetone dried homogenates of bovine nasal cartilage, but not of other tissues, markedly enhances the solubility of urate in buffers having molarities and hydrogen ion concentrations similar to that of most body fluids. The components of cartilage responsible for this effect are the proteinpolysaccharides, compounds of protein and chondroitin sulfate, called PPL. A progressive increase in PPL concentration results in a corresponding increase in urate solubility. If, on the other hand, unbound chondroitin sulfate or PPL digested by trypsin is used, then no significant augmentation of urate solubility occurs indicating that the integrity of the molecule is essential. One subfraction of PPL, PPL(5), causes an even more exaggerated response while another, PPL(3), causes a lesser one. These proteinpolysaccharide macro-molecules also inhibit the crystallization of urate from a supersaturated medium. The mechanism of the solubilizing phenomenon is not known. It is suggested that some type of physical or chemical binding is responsible. When, as a result of normal or accelerated connective tissue turnover, PPL is enzymatically destroyed, urate crystals then precipitate from the saturated tissue fluids.

Animals↗
PubMed1969

The proteinpolysaccharides of human costal cartilage.

Water-soluble proteinpolysaccharides, called PPL, can be extracted from bovine nucleus pulposus in yields of 45%, and from bovine nasal cartilage in yields of 37% of the dry tissue weight. From human costal cartilage only 7% can be extracted. The method used to separate PPL from each of the first two tissues into four distinct fractions separates the PPL of human costal cartilage into four fractions called PPL 3, PPL 4, PPL 5, and PPL 6, which show an increase in protein content, a decrease in chondroitin sulfate content, a nearly constant keratan sulfate content, and an increase in ease of sedimentability and molecular weight. From each of the three tissues mentioned. PPL 3 has a similar amino acid profile and so does PPL 5, but PPL 5 differs from PPL 3 in having a lower content of serine and higher contents of aspartic acid, tyrosine, and arginine. A more extensive effort to characterize these products has been made by analytical ultracentrifugation, and this has led to a further fractionation of PPL 5. Treatment of the cartilage residue or the water-insoluble protein polysaccharide called PPH, with neutral NH(2)OH solution releases water-soluble protein polysaccharides which in composition resemble PPL 4. The water-insoluble residue left after NH(2)OH treatment, when treated with collagenase, yields two soluble products, one resembling PPL 5 in composition, the other with a much lower chondroitin sulfate and much higher keratan sulfate content. The possibility is suggested that in human costal cartilage, binding of some forms of PPL to collagen may occur.

Age Factors↗