A calorimetric procedure was developed for assaying the enzyme activity of chondroitinase AC from Flavobacterium heparinum and of chondroitinase ABC from Proteus vulgaris when chondroitin 4-sulfate is used as a substrate. The enzymatic digestion product, 2-acetamido-2-deoxy-3-0-(/3-Dgluco-4-enepyranosyluronic acid)-4-0-s&o-D-galactose, is oxidized with periodic acid to yield, among other produc...

Composition and architecture of the extracellular matrix dictate cell behavior. Proteoglycans bind multiple components of the extracellular matrix by serving as important regulators of cell behavior. Given the influence of culture architecture on cell function, we investigated whether switching NIH3T3 fibroblasts from growth on type 1 collagen in monolayer to a collagen gel might influence derm...

Extraction of stage 22-23 chick embryo limb buds that had been metabolically labeled with [35S]sulfate yielded heparan sulfate proteoglycan, small chondroitin sulfate proteoglycan, and large chondroitin sulfate proteoglycan (designated PG-M). PG-M constituted over 60% of the total macromolecular [35S]sulfates. It was larger in hydrodynamic size, richer in protein, and contained fewer chondroiti...

In the native state, the polysaccharides of cartilage act as if they were linked to protein by bonds labile to alkali such as ester bonds. This thought was more or less clearly expressed by Krukenberg (I), Schmiedeberg (2), and Levine (3) and was based on the ease of extraction of the polysaccharides from cartilage by alkali and on their resistance to extraction by water. Practically the entire...

Recent analyses of tears indicate the presence of glycosaminoglycans as their components, but their origin remains unknown. To further understand the origin of these tear components, we investigated by immunohistochemical techniques the localization of glycosaminoglycans and CD44 human lacrimal glands obtained from 20 cadavers at autopsy. Monoclonal antibodies to CD44, a receptor for hyaluronic...

In autoradiograms of slices of costal cartilage, incubated for 4 hours in a salt solution containing S(35)-sulfate and then washed extensively and dehydrated, about 85 per cent of the radioactivity was assignable to the chondrocytes. From alkaline extracts of similarly prepared slices of cartilage, 64 to 83 per cent of the total sulfur-35 in the slices was isolated as chondroitin sulfate by chr...

The extracellular matrix is a diverse composition of glycoproteins and proteoglycans found in all cellular systems. The extracellular matrix, abundant in the mammalian central nervous system, is temporally and spatially regulated and is a dynamic "living" entity that is reshaped and redesigned on a continuous basis in response to changing needs. Some modifications are adaptive and some are mala...