1. Proteoglycans were extracted from sclera with 4 M-guanidine hydrochloride in the presence of proteinase inhibitors and purified by ion-exchange chromatography and density-gradient centrifugation. 2. The entire proteoglycan pool was characterized by compositional analyses and by specific chemical (periodate oxidation) and enzymic (chondroitinases) degradations. The glycan moieties of the mole...

To determine the time course of synaptic differentiation, we made successive observations on identified, nerve-contacted muscle cells developing in culture. The cultures had either been stained with fluorescent alpha-bungarotoxin, or were maintained in the presence of a fluorescent monoclonal antibody. These probes are directed at acetylcholine receptors (AChR) and a basal lamina proteoglycan, ...

Corneal transparency is dependent upon the development of an organized extracellular matrix containing small diameter collagen fibrils with regular spacing, organized as orthogonal lamellae. Proteoglycan-collagen interactions have been implicated in the regulation of collagen fibrillogenesis and matrix assembly. To determine the role of dermatan sulfate proteoglycan in the development and organ...

Polyclonal antibodies were raised in a rabbit against the major proteoglycan of chick sternal cartilage. A total of six antisera was obtained, three after the first booster injection (A1, A2, and A3) and three after the second booster injection (A4, A5, and A6). The A1 antiserum, which was characterized in most detail, immunoprecipitated native as well as chondroitinase ABC-digested or chondroi...

Monoclonal antibodies were raised against proteoglycan core protein isolated after chondroitinase ABC digestion of human articular cartilage proteoglycan monomer. Characterization of one of the monoclonal antibodies (1/20/5-D-4) indicated that it specifically recognized an antigenic determinant in the polysaccharide structure of both corneal and skeletal keratan sulfate. Enzyme immunoassay anal...

Heparin proteoglycan formed by incubation of purified rat peritoneal mast cells with [3KS]sulfate has previously been shown to be a proteoglycan with an approximate average molecular weight of 750,000 by gel filtration. This proteoglycan which was isolated in the absence of proteases has now been shown to contain approximately equal amounts of serine and glycine which together account for 82% o...

Corneal transparency is dependent upon the development of an organized extracellular matrix containing small diameter collagen fibrils with regular spacing, organized as orthogonal lamellae. Proteoglycan-collagen interactions have been implicated in the regulation of collagen fibrillogenesis and matrix assembly. To determine the role of dermatan sulfate proteoglycan in the development and organ...

An in-vitro study has been made of the response of aged human articular cartilage to the catabolic agent retinol. Weight bearing cartilage from the femoral condyle degrades and releases proteoglycan with an associated reduction of sulphate incorporation. Similar cartilage from the femoral head responds to the retinol with an inhibition of sulphate incorporation but no degradation or loss of pro...

The subendothelial retention of LDLs through their interaction with proteoglycans has been proposed to be a key process in the pathogenesis of atherosclerosis. In vitro studies have identified eight clusters of basic amino acids in delipidated apo-B100, the protein moiety of LDL, that bind the negatively charged proteoglycans. To determine which of these sites is functional on the surface of LD...

Cytotactin is an extracellular matrix protein that is found in a restricted distribution and is related to developmental patterning at a number of neural and non-neural sites. It has been shown to bind specifically to other extracellular matrix components including a chondroitin sulfate proteoglycan (cytotactin-binding [CTB] proteoglycan) and fibronectin. Cell binding experiments have revealed ...