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R M Mason

Publications and source records attributed to R M Mason.

At least 163 records · Page 9Linked to original sources
PubMed1973

Extraction of cartilage protein-polysaccharides with inorganic salt solutions.

1. Bovine nasal cartilage was extracted with inorganic salt solutions of various ionic strengths. The efficiency of extraction of protein-polysaccharide from the tissue was determined for each extraction. The results confirm and enlarge earlier observations (Sajdera & Hascall, 1969). 2. The chloride salts of lanthanide metals extract high yields of protein-polysaccharide from the tissue at much lower concentrations than was achieved with univalent and bivalent salts. 3. The lanthanum salt of extracted protein-polysaccharide precipitates when the concentration of LaCl(3) is decreased. Precipitation is complete in the presence of 0.05m-LaCl(3). This finding is relevant to the interpretation of earlier observations on the effect of LaCl(3) on elastic recovery of articular cartilage after compression (Sokoloff, 1963). 4. A linear relationship was found between the concentration at which a particular salt is maximally effective in solubilizing protein-polysaccharide from the tissue and the enthalpy of hydration of the cation of the salt. On the basis of this relationship a hypothesis is proposed to explain the characteristic protein-polysaccharide-extraction profiles exhibited by inorganic salt solutions.

Animals↗
PubMed1973

The composition of cartilage proteoglycans. An investigation using high- and low-inonic-strength extraction procedures.

1. A proteoglycan fraction (the proteoglycan subunit fraction) was prepared from extracts, with 0.15m-KCl (low-ionic-strength) and 0.5m-LaCl(3), 2.0m-CaCl(2) and 4.0m-guanidinium chloride (high-ionic-strength), of bovine nasal cartilage by equilibrium-density-gradient centrifugation, essentially as described by Hascall & Sajdera (1969). 2. The use of different centrifugation times showed that near-equilibrium conditions were reached by 48h for the fractions prepared from the high-ionic-strength extracts. The fraction isolated from the low-ionic-strength extract required a longer centrifugation time to reach equilibrium conditions. 3. The composition of the proteoglycan fractions from the various extracts was compared by analyses of their carbohydrate and amino acid contents. Difference indices were calculated from the amino acid analysis to compare the degree of compositional relationship between the protein components of the proteoglycans. 4. Small compositional differences were found between the proteoglycans isolated from the various high-ionic-strength extracts. The protein content of the fractions from the CaCl(2) extract and the guanidinium chloride extract showed the greatest difference in this respect, although their amino acid analysis was similar. 5. The proteoglycan fraction isolated from the low-ionic-strength extract shows marked differences in composition from the fractions isolated from the high-ionic-strength extracts. Its protein and glucosamine contents were lower whereas its hexuronic acid and galactosamine contents were higher than those of the latter. It also exhibits major differences in its amino acid composition. The glucosamine:galactosamine ratio of the fraction from the low-ionic-strength extract indicates that it may be an almost exclusively chondroitin sulphate-proteoglycan. Its analysis correlates closely with that of a low-molecular-weight proteoglycan isolated from pig laryngeal cartilage by Tsiganos & Muir (1969). 6. The proteoglycan fractions from both the low- and high-ionic-strength extracts migrate as a single band in zone electrophoresis carried out in a sucrose-density gradient at both pH3.0 and pH7.0, although each showed evidence of band widening during the electrophoresis. All the proteoglycan fractions migrated with the same electrophoretic mobility at pH3.0, irrespective of the differences in composition between them. 7. The differences between the proteoglycans from the low- and high-ionic-strength extracts are discussed and the view is advanced that they may be due to association between predominantly chondroitin sulphate-proteoglycans and a keratan sulphate-enriched proteoglycan species.

Amino Acids↗
PubMed1971

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Delivery of Health Care↗
PubMed1970

The glycosaminoglycans of human tracheobronchial cartilage.

1. The glycosaminoglycans of human tracheobronchial cartilages from subjects of various ages were liberated by proteolysis of the tissue and purified by ion-exchange chromatography. Purified glycosaminoglycans were fractionated on Dowex 1 resin and cetylpyridinium chloride was used to separate chondroitin sulphates and keratan sulphates occurring in the same fraction. 2. The total chondroitin sulphate content of the cartilages decreased linearly with increasing age. Age-dependent changes in the chemical heterogeneity of chondroitin sulphate were observed, a low-sulphated compound making up 25% of the total glycosaminoglycan at birth but rapidly diminishing in content during the first 6 months of life. Of the total chondroitin sulphate the 6-isomer became rather more prominent than the 4-isomer with increasing age. 3. The total keratan sulphate content of the cartilages increased from trace amounts only at birth to a plateau value by the beginning of the fifth decade. Of the total keratan sulphate approx. 70% was due to a high-molecular-weight compound with a sulphate/hexosamine ratio of 1.5-1.8: 1.0. The degree of sulphation varied between compounds isolated from different individuals. The remaining 30% of the keratan sulphate appeared to be intimately associated with chondroitin 6-sulphate and could only be separated from it after treatment with 0.45m-potassium hydroxide. The hybrid glycosaminoglycans were of lower molecular weight and had a lower sulphate/hexosamine ratio than the major keratan sulphate compound.

Adolescent↗