Structure and functions of Glycosaminoglycans: a short review (with some personal scientific contributions)

Abstract

Abstract This present article wishes to underline the strong contribution to both structure and functions of living bodies of a group of acidic polysaccharides, the Glycosaminoglycans (GAGs), usually covalently linked to proteins to give Proteoglycans (PGs): GAGs and PGs are structural components of connective tissues and of tissue extracellular matrix, also present on cell membrane surface and in secretory granules. Their basic structure is very simple: a linear repeat of disaccharide units, each composed of uronic acid and hexosamine moieties. However, except unsulphated high molecular weight Hyaluronan, they show very high structural heterogeneity, due to the chemical nature of both uronic acid and aminosugar components, the degree of monosaccharide sulphation, the distribution of O- and N-sulphate groups, the length of the chain and its copolymeric degree, the nature of interacting protein in PGs. So they are able to interact with a large variety of molecular structures, including matrix proteins, growth factors, cytokines and chemokines, and enzymes. Many functions in connective tissues are known GAG-depending. Many others in the body are expected. In this short review, to each one of the selected topics, GAGs synthesis, distribution, catabolism and related inborn errors, PGs functions, some personal scientific contributions will be recalled.

Keywords

• glycosaminoglycans
• proteoglycans
• extracellular matrix
• mucopolysaccharidoses
• human plasma