Table 3 Chemical nature of glycosaminoglycans

Names of glucosaminoglycans	Disaccarides	Bounds between monomeres	The place of sulphuric acid
Hyaluronic acid	Glucuronic acid + acetylglucosamin	b-1,3-glicoside	-
Chondroitinsulfate A	Glucuronic acid + acetylgalactosamine sulfate	b-1,3-glicoside	C4
Chondroitinsulfate C	Glucuronic acid + acetylgalactosamine sulfate	b-1,3-glicoside	C6
Chondroitinsulfate B	Iduronic + acetylgalactosamine sulfate	b-1,3-glicoside	C4
Keratansulfate	Galactose + acetylglucosamin	b-1,4-glicoside	C6
Heparin	Glucuronic acid + acetylglucosaminsulfate	b-1,4-glicoside	C2, C6

Glycosaminoglycans can be to present not only in the proteoglycans, but in the three form and in the such form they performance very important biological role in the animal body. They bond near 70-80% of extracellular water, they are polyanions, have very large negative charge, and they bound cations. They take part in the formation fibrillar structure, basal membranes, in the diffision of different substances. Glycosaminoglycans regulate the growth and differentation of cells and fibrillogenes. They regulate the begining and the ending mitogenesis. So, Hyaluronic acid stimulate but chondroitinsulfates and heparin inhibite the growth of cells.

Glycosaminoglycans have short chain of disaccarides (near 100). They are bounded to hydroxil group of serine in protein molecule. So we received molecule of proteoglycans. Such complexes are bounded to hyaluronic acid ( from 100-20000 disaccarides). The huge macromolecules are formed they are bounded with structural proteins, collagen, elastin. All together they forme molecular sieve which regulate diffusion of water and metabolites: aminoacids, lipids, especially in the unvessels tissues – wall of vessels, valves of heart, cartilags, cornea.

The changes the ratio between hyaluronic acids and chondroitin sulfates during the aging are the couse of atherosclerosis development.

There are a few kinds of proteoglycans: proteoglycans from a cartilages, consist from 5-10% of proteins and 90-95% of chondroitin sulfates.

Proteoglycans from synovial fluid contains 2,2-3,0 % proteins and hyaluronic acid 97,7-97,8% .

Hyaluronic acid has a big molecular mass and links water, is a main intercellular cement substance is placed in a vitreous humor of the eye, synovial fluid has property of lubrication and forms hyaluronic acid barrier against the invading agents and many bacteria.

Enzyme hyaluronidase which break up hyaluronic acid are produced by many bacteria, by the sting of bees and shake venom and different tissues of man-testes, synovial fluid. The hyaluronidase destroys the intercellular hyaluronic acid barrier and permits the invanding agents to penetrate into the tissues. In the seminal fluid hyaluronidase to facilitate fertitization of the ovum.

Chondroitin sulfates have a large significance in the fibrillogeneses and calcification.

Heparin is syntetized by the most cells in connective tissue. It found in liver, spleen, lungs, thymus and regulates the coagulation as a anticoagulant and lipid metabolism (it is activator of lipase and lipoproteinlipase. That is why it has antiatherogenic action. Heparin reduces the metabolism of cells, due to change electical potential of cellular membranes, that inhibites the growth of immunocytes and blocade of phagocytoses. Heparin inhibites some lysosomal enzymes, hyaluronidase reduces the penentration, reduces the quantaty of histamine that is why heparin has antiinflammation action.

<== попередня сторінка	\|	наступна сторінка ==>
Proteoglycans	\|	Nucleoproteins (NP)

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