scholarly journals Mode of degradation of the chondroitin sulphate proteoglycan in rat costal cartilage

1972 ◽  
Vol 130 (3) ◽  
pp. 729-738 ◽  
Author(s):  
Å. Wasteson ◽  
U. Lindahl ◽  
A. Hallén
Keyword(s):  
Molecular Weight ◽  
Tissue Culture ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Chondroitin Sulphate ◽  
Costal Cartilage ◽  
Radioactive Material ◽  
Sulphate Proteoglycan ◽  
Chondroitin Sulphate Proteoglycan

1. Chondroitin sulphate was isolated from different regions of rat costal cartilage after extensive proteolysis of the tissues. The molecular weight, determined by gel chromatography, of the polysaccharide obtained from an actively growing region (lateral zone) near the osteochondral junction was higher than that of the polysaccharide isolated from the remaining portion of the costal cartilage (medial zone). 2. In both types of cartilage the molecular weight of chondroitin sulphate, labelled with [35S]sulphate, remained unchanged in vivo over a period of 10 days, approximately corresponding to the half-life of the chondroitin sulphate proteoglycan. The molecular-weight distribution of chondroitin [35S]sulphate, labelled in vivo or in vitro, was invariably identical with that of the bulk polysaccharide from the same tissue. It is concluded that the observed regional variations in molecular-weight distribution were established at the time of polysaccharide biosynthesis. 3. In tissue culture more than half of the 35S-labelled polysaccharide–proteins of the two tissues was released into the medium within 10 days of incubation. The released materials were of smaller molecular size than were the corresponding native proteoglycans. In contrast, the molecular-weight distribution of the chondroitin [35S]sulphate (single polysaccharide chains) remained constant throughout the incubation period. 4. A portion (about 20%) of the total radioactive material released from 35S-labelled cartilage in tissue culture was identified as inorganic [35S]sulphate. No corresponding decrease in the degree of sulphation of the labelled polysaccharide could be detected. These findings suggest that a limited fraction of the proteoglycan molecules had been extensively desulphated. 5. It is suggested that the initial phase of degradation involves proteolytic cleavage of the proteoglycan, but the constituent polysaccharide chains remain intact. The partially degraded proteoglycan may be eliminated from the cartilage by diffusion into the circulatory system. An additional degradative process, which may occur intracellularly, includes desulphation of the polysaccharide, probably in conjunction with a more extensive breakdown of the polymer.

The role of glycosaminoglycans in anuran pigment cell migration

Development ◽  
1986 ◽  
Vol 92 (1) ◽  
pp. 145-164
Author(s):  
R. P. Tucker
Keyword(s):  
Chondroitin Sulphate ◽  
Pigment Cell ◽  
Ruthenium Red ◽  
Pigment Cells ◽  
Blue Staining ◽  
Alcian Blue Staining ◽  
Dorsal Margin ◽  
Sulphate Proteoglycan ◽  
Chondroitin Sulphate Proteoglycan

The migratory pathways of neural crest-derived pigment cells were examined in two anurans, Xenopus laevis and Discoglossus pictus, and correlated with the distribution of glycosaminoglycans (GAG) in the extracellular matrix (ECM) of these pathways. In Xenopus, melanophores in the trunk reach the dermis by initially migrating ventrally, between the neural tube and somites, and then by migrating through the somites to reach the subectodermal space. In Discoglossus, melanophores, iridophores, and xanthophores migrate laterally over the dorsal margin of the somites to reach the dermis. GAG was identified in the light microscope using alcian blue staining and in the electron microscope using ruthenium red staining. The ECM at the dorsal entrance to the lateral pathway in Xenopus and in young Discoglossus (at a stage prior to invasion by pigment cells) is filled with 25–50 nm chondroitin sulphate proteoglycan aggregates. When this ECM in Xenopus is digested in vivo with chondroitinase ABC, melanophores enter the lateral pathway. In older Discoglossus embryos, the migration of pigment cells into the lateral pathway is correlated with increases in the space between the ectoderm and somites and in the number of hyaluronate microfibrils. These observations suggest that chondroitin sulphate proteoglycan in the subectodermal ECM restricts the migration of pigment cells into the lateral pathway by limiting the amount of space for migration and possibly by acting as a less adhesive migratory substratum than the ventral pathway, and that in Discoglossus hyaluronate opens spaces permitting the migration of pigment cells directly over the dorsal margin of the somites.

scholarly journals The molecular-weight distribution of glycosaminoglycans

1973 ◽  
Vol 135 (4) ◽  
pp. 631-637 ◽  
Author(s):  
John J. Hopwood ◽  
H. Clem Robinson
Keyword(s):  
Molecular Weight ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Chondroitin Sulphate ◽  
Average Molecular Weight ◽  
Length Distribution ◽  
Accurate Estimation ◽  
Distribution Data ◽  
Gel Chromatography ◽  
Chain Length Distribution

1. A rapid and sensitive method for the accurate estimation of the molecular-weight distribution of keratan sulphate and chondroitin sulphate isolated from adult bovine nasal septum and intervertebral disc is described. The method utilizes gel chromatography of reductively labelled glycosaminoglycan and end-group estimation of number-average molecular weight for each fraction across the peak of eluted glycosaminoglycan. 2. Chain-length distribution data obtained by this procedure are used to evaluate mechanisms of chondroitin sulphate biosynthesis.

scholarly journals Studies on the polydispersity and heterogeneity of cartilage proteoglycans. Identification of 3 proteoglycan structures in bovine nasal cartilage

1975 ◽  
Vol 151 (3) ◽  
pp. 581-594 ◽  
Author(s):  
J J Hopwood ◽  
H C Robinson
Keyword(s):  
Molecular Weight ◽  
Density Gradient ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Chondroitin Sulphate ◽  
Relative Proportion ◽  
Average Molecular Weight ◽  
Nasal Cartilage ◽  
Cscl Density Gradient ◽  
Gradient Fractionation

1. Three chondroitin sulphate components were isolated from adult bovine nasal cartilage after treatment with alkaline NaB3H4. Average molecular weights of 13000, 18 600 and 28 000 were obtained for chondroitin sulphate species representing 10, 52 and 38% (w/w) of the total chondroitin sulphate respectively. Each chondroitin sulphate pool has a narrow molecular-weight distribution. 2. A proteoglycan subunit preparation, isolated from one nasal cartilage by extraction and density-gradient fractionation in dissociative solvents, partitioned on a CsCl density gradient according to size and composition. Variation of proteoglycan molecular weight across the gradient was directly related to the average chondrotin sulphate chain length, which in turn reflected the relative proportion of the three chondroitin sulphate pools in each proteoglycan fraction. Consideration of proteoglycan molecular parameters, compositions and behaviour on sedimentation leads to a proposal that nasal cartilage contains 3 distinct proteoglycan pools, each of which has a constant number of chondroitin sulphate side chains of different average molecular weight. 3. Molecular-weight distribution parameters for these proteoglycan preparations indicate that all serine residues on the protein core capable of initiating chondroitin sulphate biosynthesis are occupied and that proteoglycan polydispersity results directly from the polydispersity of the attached chondroitin sulphate component.

Studies on Metabolism of Urokinase and Mechanism of Thrombolysis by Urokinase

1979 ◽  
Vol 42 (03) ◽  
pp. 885-894 ◽  
Author(s):  
Tatsuo Ueno ◽  
Norio Kobayashi ◽  
Tadashi Maekawa
Keyword(s):  
Molecular Weight ◽  
Plasma Clearance ◽  
Radioactive Material ◽  
Optimal Dosage ◽  
Plasma Clot ◽  
Optimal Dosage Regimen ◽  
Arterial Thrombus ◽  
Contact Experiment

SummaryPharmacokinetics of intravenously injected 125I-labeled urokinase (125I-UK) of a molecular weight of 33,000 daltons in normal rabbits and patients with various diseases were investigated. The plasma clearance of 125I-UK in rabbits was described by a biexponential curve within six hours with a half-life of 8 minutes, 2.3 hours, respectively. The radioactivity in the liver and kidneys 15 minutes after iv injection with 125I-UK was 9.6% and 14.0% of the radioactivity injected, respectively. Approximately 80% of the total radioactive material injected was excreted in the urine in 18 hours. No increase in activator activity in the urine was observed after a large amount of UK injection. Activity uptake of 125I-UK by experimentally induced arterial thrombus was little. Lysis of the stasis thrombus was produced by injecting 7.5 × 104 IU of UK in only one out of 8 rabbits. In vitro contact experiment revealed that transfer of 125I-UK to plasma clot is slow (24 hours for 10% of 125I-UK by plasma clot). In 4 patients plasma clearance of 125I-UK was essentially similar to that in rabbits. From the results obtained optimal dosage regimen of UK administration for complete thrombolysis in vivo was discussed.

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