Perlecan and Basement Membrane-Chondroitin Sulfate Proteoglycan (Bamacan) Are Two Basement Membrane Chondroitin/Dermatan Sulfate Proteoglycans in the Engelbreth-Holm-Swarm Tumor Matrix

John R. Couchman, Rajesh Kapoor, Meenakshi Sthanam, Rong-Rong Wu
1996 Journal of Biological Chemistry  
The presence of proteoglycans bearing galactosaminoglycan chains has been reported, but none has been identified previously in the matrix of the Engelbreth-Holm-Swarm tumor, which is a source of several basement membrane components. This tumor matrix contains perlecan, a large, low buoyant density heparan sulfate proteoglycan, widespread in many basement membranes and connective tissues. We now identify two distinct proteoglycan species from this tumor source, which are substituted with
more » ... ituted with galactosaminoglycans and which show basement membrane localization by immunohistochemistry. One species is perlecan but, in addition to being present as a heparan sulfate proteoglycan, it is also present as a hybrid molecule, with dermatan sulfate chains. A minor population of perlecan apparently lacks heparan sulfate chains totally, and some of this is substituted with chondroitin sulfate. The second species is immunologically related to basement membrane-chondroitin sulfate proteoglycan (BM-CSPG) and bears chondroitin sulfate chains. No BM-CSPG was detectable which was substituted with heparan sulfate chains. A combination of immunological and molecular approaches, including cDNA cloning, showed that perlecan and BM-CSPG are distinct in core protein structure. Both are, however, basement membrane components, although there are tissue-specific differences in their distribution.
doi:10.1074/jbc.271.16.9595 pmid:8621634 fatcat:6452ooffdfchbo35yuewxbozom