scholarly journals Characterization of the tissue-specific proteoglycans synthesized by chondrocytes from nanomelic chick embryos.

1982 ◽  
Vol 201 (2) ◽  
pp. 387-394 ◽  
Author(s):  
P J McKeown-Longo ◽  
P F Goetinck
Keyword(s):  
Gradient Analysis ◽  
Chondroitin Sulphate ◽  
Guanidine Hydrochloride ◽  
Sucrose Density Gradient ◽  
Void Volume ◽  
Normal Cartilage ◽  
Controlled Pore Glass ◽  
Pore Glass

Cartilage from the avian mutant nanomelia has been reported to synthesize cartilage-specific proteoglycans, PGS(SC)-I, at 1-2% of normal values [McKeown & Goetinck (1979) Dev. Biol. 71, 203-215]. Proteoglycans were endogenously labelled with [35S]sulphate and extracted from cartilage in 4 M-guanidine hydrochloride and chromatographed on controlled-pore glass 1400. PGS(SC)-I was obtained from the void volume of these columns. Dissociative sucrose-density-gradient analysis revealed a greater than normal polydispersity in the nanomelic PGS(SC)-I. Fractions from both the controlled-pore glass 1400 void volume and sucrose gradients were tested for their ability to bind specific antibody against cartilage proteoglycan monomer. In all instances, binding of normal fractions was greater than 90%, whereas binding to nanomelic fractions ranged from 20 to 65%. Chromatography of PGS(SC)-I on controlled-pore glass 2500 resulted in 70% of the normal and 25% of the mutant proteoglycans eluting as aggregates. Chondroitin sulphate chains from mutant PGS(SC)-I appeared slightly larger than normal when chromatographed on controlled-pore glass 500. In addition, PGS(SC)-I from nanomelic cartilage is more susceptible to proteolysis in vitro than the PGS(SC)-I from normal cartilage. This evidence suggests that the small amount of cartilage-specific proteoglycan synthesized by nanomelic cartilage is not normal.

scholarly journals Biosynthesis of proteoglycans in cartilage slices. Fractionation by gel chromatography and equilibrium density-gradient centrifugation

1972 ◽  
Vol 126 (4) ◽  
pp. 791-803 ◽  
Author(s):  
T. E. Hardingham ◽  
Helen Muir
Keyword(s):  
Density Gradient ◽  
Density Gradient Centrifugation ◽  
Chondroitin Sulphate ◽  
Gradient Centrifugation ◽  
Guanidine Hydrochloride ◽  
Specific Radioactivity ◽  
Equilibrium Density ◽  
Gel Chromatography ◽  
Sulphate Content

The kinetics of incorporation of [35S]sulphate into slices of pig laryngeal cartilage in vitro was linear with time up to 6h. The specific radioactivities of the extracted proteoglycans (containing about 80% of the uronic acid of the cartilage) and the glycosaminoglycans remaining in the tissue after extraction were measured after various times of continuous and ‘pulse–chase’ radioactivity incorporation. Radioactivity was present in the isolated chondroitin sulphate after 2 min, but there was a 35min delay in its appearance in the extractable proteoglycan fraction. Fractionation of the proteoglycans by gel chromatography showed that the smallest molecules had the highest specific radioactivity, but ‘pulse–chase’ experiments over 5h did not demonstrate any precursor–product relationships between fractions of different size. Equilibrium density-gradient centrifugation in 4m-guanidine hydrochloride showed that among the proteoglycan fractions the specific radioactivity increased as the chondroitin sulphate content decreased, but with preparations from ‘pulse–chase’ experiments there was again no evidence for precursor–product relationships between the different fractions. Differences in radioactive incorporation would seem to reflect metabolic heterogeneity within the proteoglycans extracted from cartilage. This may be due either to a partial separation of different types of proteoglycans or to differences in the rates of degradation of the molecules of different size and composition as a result of the nature and specificity of the normal degrading enzymes. The results suggest that molecules of all sizes were formed at the same time.

scholarly journals Proteoglycans in normal and severely osteoarthritic human cartilage

1980 ◽  
Vol 187 (3) ◽  
pp. 781-787 ◽  
Author(s):  
N Vasan
Keyword(s):  
Core Protein ◽  
Chondroitin Sulphate ◽  
Binding Capacity ◽  
Osteoarthritic Cartilage ◽  
Human Cartilage ◽  
Controlled Pore Glass ◽  
Pore Glass ◽  
Proteoglycan Aggregates ◽  
Two Peaks ◽  
Two Populations

Proteoglycans from osteoarthritic cartilage were compared with those from normal articular cartilage. Normal proteoglycan aggregates are larger in size and more homogeneous than those in osteoarthritis. Proteoglycan monomers from both sources gave two peaks on controlled pore glass-bead chromatography. Although the retarded material from normal cartilage showed an affinity for hyaluronate, the same material from osteoarthritic cartilage did not. The hyaluronate-binding capacity of the material which is partly in the void volume and partly retarded was similar in both types of cartilage. These results suggest that in osteoarthritic cartilage the proteoglycan aggregates are smaller and more heterogeneous and that the chondroitin sulphate side chains are shorter. They also indicate that there are two populations of proteoglycan, one with its hyaluronate-binding-protein region of core protein intact and the other either possessing an inactive binding region or totally lacking it.

scholarly journals The Characterization of Scintillons

1968 ◽  
Vol 51 (1) ◽  
pp. 105-122 ◽  
Author(s):  
Richard DeSa ◽  
J. Woodland Hastings
Keyword(s):  
Intact Cell ◽  
Gradient Centrifugation ◽  
Sucrose Density Gradient ◽  
Sucrose Density Gradient Centrifugation ◽  
Chemical Treatments ◽  
New Type ◽  
Physical And Chemical ◽  
Biological Particle

A new type of biological particle, isolated from the marine dinoflagellate Gonyaulax polyedra, has been partially purified and characterized. When the pH is lowered, the particle emits light in vitro in a fashion closely mimicking the flash of the living cell, and it is referred to as a scintillon (flashing unit). Scintillons are obtained by breaking the cells in buffer at pH 8.2 and purifying by differential and sucrose density gradient centrifugation. The particle has a density of about 1.23 g cc-1, and activity is quantitatively correlated with the number of crystal-like birhombohedral structures. These have been found to contain guanine, but since the density of authentic guanine is about 1.73 g cc-1, the scintillon is believed to comprise additional but as yet unidentified components. The properties of the scintillon and the effects of various physical and chemical treatments are described. The reasons for believing that this particle is responsible for the flash of the intact cell are discussed.

scholarly journals Isolation and characterization of high-buoyant-density proteoglycans from bovine femoral-head cartilage

1983 ◽  
Vol 213 (2) ◽  
pp. 355-362 ◽  
Author(s):  
M Lyon ◽  
J Greenwood ◽  
J K Sheehan ◽  
I A Nieduszynski
Keyword(s):  
Light Scattering ◽  
Femoral Head ◽  
Chondroitin Sulphate ◽  
Guanidine Hydrochloride ◽  
Buoyant Density ◽  
Radius Of Gyration ◽  
Gel Chromatography ◽  
Isolation And Characterization ◽  
Femoral Head Cartilage

Proteoglycans were extracted from bovine (15-18 months old) femoral-head cartilage. The heterogeneity of the A1D1 proteoglycan fraction was examined by gel chromatography, sedimentation velocity, sucrose rate-zonal centrifugation and CS2SO4 isopycnic centrifugation. In all cases polydisperse but unimodal distributions were obtained. Chemical analysis of the preparation yielded a galactosamine/glucosamine molar ratio of 7:1, and 13C n.m.r. spectroscopy showed that the chondroitin sulphate comprised equal proportions of the 4- and 6-sulphate isomers. Gel chromatography of a papain and Pronase digest of the proteoglycan indicated that the chondroitin sulphate chains had a Mn of approx. 10500. The mean buoyant density of the proteoglycan in pure CS2SO4 was 1.46 g/ml. Physical characterization of the proteoglycan preparation in 4M-guanidine hydrochloride, pH 7.4, by using conventional light-scattering gave a radius of gyration of 42 nm and a Mw of 0.96 × 10(6). Quasi-elastic light-scattering in the same solvent yielded a translational diffusion coefficient, D020, of 5.41 × 10(-8) cm2 × S-1, and ultracentrifugation gave a sedimentation coefficient, S020, of 12.0S. Thus from sedimentation-diffusion studies a Mw of 1.36 × 10(6) was calculated. The possible origins for the differences in the two molecular-weight estimates are discussed. It is concluded that the high-buoyant-density proteoglycans from bovine articular cartilage are significantly smaller than those from bovine nasal septum, and that this is largely due to the smaller size of their chondroitin sulphate chains.

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