Purification of amyloid-associated heparan sulphate proteoglycans and galactosaminoglycan free chains from human...

Basement membrane-associated heparan sulphate proteoglycans have been demonstrated immunohistochemically in organs from patients afflicted with various types of amyloidosis. In a recent report, we were able to isolate and partly characterize a basement membrane-associated heparin sulphate proteoglycan from human hepatic amyloid. In the present study proteoglycans were extracted with guanidine from human amyloid-laden kidney, spleen and lymph nodes. All tissues extracted with guanidine contained both heparan sulphate proteoglycan (HSPG) and galactosaminoglycan (CS/DS) free chains. Tissue staining using a monoclonal antibody against basement membrane HSPG revealed the presence of HSPG in amyloid deposits in kidney and spleen. Furthermore, following SDS-PAGE of HSPG from kidney after deaminative cleavage of the HS chains, a 15-kDa and 80-kDa protein appeared, probably representing the core protein(s). In lymph node HSPG, three core proteins of 65, 30 and 25 kDa could be demonstrated on SDS-PAGE, the first reacting with the anti-basement membrane HSPG antibody when subjected to Western blotting subsequent to SDS-PAGE. By immunohistochemistry, we failed to demonstrate any staining of the renal and splenic tissue sections employing an antibody against the decorin core protein.