Heparin Sulphate Proteoglycans

Resident mouse peritoneal macrophages synthesise and secrete equivalent amounts of heparan sulphate and chondroitin sulphate proteoglycans (Kolset 1987). 

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Libeu, C.P., Lund-Katz, S., Phillips, M.C., et al. (2001) New insights into the heparin sulphate proteoglycan-binding activity of apolipoprotein E. J. Biol. Chem., 276, 39138-39144. 

The structure of PTPo is consistent with its role in binding ligands on the surface of other cells or in the extracellular matrix. It interacts with heparin sulphate proteoglycan in the basement membrane (Sajnani-Perez et al. 2003). It may also bind to the C-terminal domain of cell surface-exposed nucleolin, a normally nuclear protein that is presented on the surface of developing muscle cells (Alete et al. 2006). However, these complexes seem to mediate structural or long-term regulatory interactions rather than short-term signaling to the neuronal secretory machinery. 

C. Proteoglycans can be found in all basement membranes. Proteoglycans with three-heparin sulphate attached to the core protein perlecan predominate. A decrease in the glomerular content of heparin sulphate proteoglycans occurs in a number of renal diseases. 

The glycosaminoglycans family is composed of hyaluronic acid, chon-droitin sulphates, dermatan sulphate, heparan sulphate, heparin and keratan sulphate. They are present in diverse tissues, mainly as branches of very large proteoglycans, in which the core is constituted by proteins. Glycosaminoglycans are water-soluble or highly swollen. In this family, heparin itself constitutes a subfamily, as its composition and the resulting activities are diverse. For this reason, it may be more properly designated as heparins . 

A polyprenyl derivative of 2-acetamido-2-deoxy-4-0-(D-glucopyranosyluronic acid)-D-glucopyranose isolated from human fibroblasts transformed by simian virus 40 may be involved in the synthesis of the disaccharide rep>eating-unit of such proteoglycans as heparin. Heparan sulphate has been identified as the principal sulphated glycosaminoglycan synthesized in vitro by acinar cells from rat pancreas in the presence of sulphate ions, although the levels of heparan sulphate synthesized were very low. ... 

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