scholarly journals The effects of proteolytic enzymes on the hyaluronic acid complex of ox synovial fluid

1957 ◽  
Vol 66 (2) ◽  
pp. 342-346 ◽  
Author(s):  
B. S. Blumberg ◽  
A. G. Ogston
1951 ◽  
Vol 49 (5) ◽  
pp. 585-590 ◽  
Author(s):  
A. G. Ogston ◽  
J. E. Stanier

1956 ◽  
Vol 63 (4) ◽  
pp. 715-717 ◽  
Author(s):  
B. S. Blumberg ◽  
A. G. Ogston

1970 ◽  
Vol 11 (2) ◽  
pp. 139-155 ◽  
Author(s):  
Nils W. Rydell ◽  
Judson Butler ◽  
Endre A. Balazs

Cells ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 1606 ◽  
Author(s):  
Weifeng Lin ◽  
Zhang Liu ◽  
Nir Kampf ◽  
Jacob Klein

Hydration lubrication has emerged as a new paradigm for lubrication in aqueous and biological media, accounting especially for the extremely low friction (friction coefficients down to 0.001) of articular cartilage lubrication in joints. Among the ensemble of molecules acting in the joint, phosphatidylcholine (PC) lipids have been proposed as the key molecules forming, in a complex with other molecules including hyaluronic acid (HA), a robust layer on the outer surface of the cartilage. HA, ubiquitous in synovial joints, is not in itself a good boundary lubricant, but binds the PC lipids at the cartilage surface; these, in turn, massively reduce the friction via hydration lubrication at their exposed, highly hydrated phosphocholine headgroups. An important unresolved issue in this scenario is why the free HA molecules in the synovial fluid do not suppress the lubricity by adsorbing simultaneously to the opposing lipid layers, i.e., forming an adhesive, dissipative bridge between them, as they slide past each other during joint articulation. To address this question, we directly examined the friction between two hydrogenated soy PC (HSPC) lipid layers (in the form of liposomes) immersed in HA solution or two palmitoyl–oleoyl PC (POPC) lipid layers across HA–POPC solution using a surface force balance (SFB). The results show, clearly and surprisingly, that HA addition does not affect the outstanding lubrication provided by the PC lipid layers. A possible mechanism indicated by our data that may account for this is that multiple lipid layers form on each cartilage surface, so that the slip plane may move from the midplane between the opposing surfaces, which is bridged by the HA, to an HA-free interface within a multilayer, where hydration lubrication is freely active. Another possibility suggested by our model experiments is that lipids in synovial fluid may complex with HA, thereby inhibiting the HA molecules from adhering to the lipids on the cartilage surfaces.


1978 ◽  
Vol 173 (1) ◽  
pp. 237-243 ◽  
Author(s):  
M Isles ◽  
A R Foweraker ◽  
B R Jennings ◽  
T Hardingham ◽  
H Muir

An electric field causes partial alignment of macromolecules in a dilute solution. The accompanying changes in the solution birefringence offer a sensitive and quick means of monitoring the rates of particle orientation and hence the size of the solute molecules. Such measurements are reported for dilute solutions of proteoglycans in the absence and presence of added hyaluronic acid. The proteoglycan molecules are shown to be some 580 nm long. In the presence of hyaluronic acid they form aggregates that appear to be consistent with the model previously proposed in which the proteoglycans attach radially to the extended hyaluronic acid chain. The electric-birefringence relaxation rates indicate aggregates of similar length to that of the extended hyaluronic acid chain, with the proteoglycans spaced on average at 29nm intervals. A proteoglycan sample the cystine residues of which had been reduced and alkylated showed no evidence of aggregation with hyaluronic acid up to the concentrations of the acid corresponding to 1% of the total uronic acid content. The electric-birefringence method is shown to have a large potential in the study of associating polysaccharide solutions.


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