The link protein and proteoglycan amino-terminal globular domains have similar structures
Cartilage proteoglycan aggregates contain two components (proteoglycan monomer and link protein ) which interact with each other and with hyaluronic acid
Data from amino acid sequence analysis are presented that shows that a domain of the proteoglycan , the hyaluronic acid binding region , which interacts with link protein and hyaluronic acid is very similar to link protein in terms of its primary structure
However, the pattern of glycosylation in the hyaluronic acid binding region is different from that found in link protein
After removal of N-linked oligosaccharides, the tryptically prepared hyaluronic acid binding region from rat chondrosarcoma has a mass by sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of 43 +/- 2 kDa
The COOH-terminal two-thirds of rat chondrosarcoma link protein , starting at residue 105 , has 41.3% identity with a similar region in the hyaluronic acid binding region
We show that, in addition to the hyaluronic acid binding region , proteoglycan contains another region with similarity to the two repeating loop structures in the COOH-terminal two-thirds of link protein
This presumably corresponds to the second globular domain reported in rotary shadowing studies of cartilage proteoglycans
We have deduced the positions of all of the disulfide bonds in the hyaluronic acid binding region and find them to be in the same positions as would be expected from comparison of these sequences with link protein