HEPARAN-SULFATE - A PIECE OF INFORMATION

he sulfated glycosaminoglycans, heparan sulfate and heparin, are incre asingly implicated in cell-biological processes such as cytokine actio n, cell adhesion, and regulation of enzymic catalysis, These activitie s generally depend on interactions of the polysaccharides with protein s, mediated by distinct saccharide sequences, and expressed at various levels of specificity, selectivity, and molecular organization. The f ormation of heparin/heparan sulfate in the cell requires an elaborate biosynthetic machinery, that is conceived in terms of a novel model of glycosaminoglycan assembly and processive modification, Recent advanc es in the identification and molecular analysis of the enzymes and oth er proteins involved in the biosynthesis provide novel tools to study the regulation of the process, presently poorly understood, at the sub cellular and cellular levels, The potential medical importance of hepa rin-related compounds is likely to promote the biotechnological exploi tation of components of the biosynthetic machinery.