Polysaccharides heparin

Proteoglycans are major components of the extracellular matrix in animal cells. They are composed of core proteins and glycosaminoglycan polysaccharides. Heparin and heparan sulfate are the most complex glycosaminoglycans, a family of molecules that also includes chon-... 

The sulfated polysaccharide, heparin, is used as a powerful anticoagulant and acts by inhibiting one of the later stages in the interaction cascades leading to clot development (20, ij). This action is intimately associated with the negative charge on the molecule, for a number of other sulfated polysaccharides are also effective (43-45), and polysaccharides and synthetic polymers with quartemary ammonium functions act as heparin antagonists (46). 

The dimethylamino sugar mycaminose is a constituent of riiacrolide antibiotics synthesized in Actinomycetes (D 4). 2-Methylamino-L-glucose and 2,6-diamino-D-glucose are building blocks of amino and guanidino cyclitol antibiotics (D 1.3). Also the polysaccharides heparin, chondroitin sulfate, and hyaluronic acid (Table 22) formed in animals contain amino sugars. 

The added polymers range from polysaccharides (heparin, chondroitin sulfate, dextran) to polyethylene oxide (PEO) and polystyrene (PS). 

As early as 1942, Cohen [9] observed, in a study directed at the isolation of TMV from infectious juice, that the addition of 5 mg/ml of the polysaccharide heparin to a dilute TMV suspension (2 mg/ml) in 0.1 M phosphate buffer (pH = 7.1) resulted in the production of needle-shaped paracrystals of length 5-20 pm... 

Macromolecular group-specific ligands include proteins that are used widely in the purification of biologically relevant macromolecules. Important macromolecular ligands are lectins (for the isolation of glycoproteins), protein A and protein G (for the purification of immunoglobulins), calmodulin (for Ca-dependent enzymes), and the polysaccharide heparin (for the purification of clotting factors and other plasma proteins). 

Another approach utilizes the grafting of the sulfate-containing polysaccharide heparin onto the blood-contacting surface. This material prevents coagulation and concomitant thrombosis. The strong anionic character of heparin enables it to bond ionically to cationic surfaces. The heparin is slowly released into the bloodstream. During this release process, the concentration of heparin near the surface is sufficiently high to prevent the formation of a thrombus for several days. Unfortunately, after this period of time, the release rate decreases. Thus, this approach is only suitable for use in short-term devices. 

Polysaccharides (heparin (in high concentrations), chondroitin sulfate)... 

Badr HA, Feiler J, Bachas LG. Response behavior of sodium-selective electrodes modified by surface attachment of the anticoagulant polysaccharides heparin and chondroitin sulfate. Talanta 2005 65(l) 261-6. 

It turned out that the dynamical behaviour of polyelectrolyte solutions is even more spectacular then theoretically anticipated. In the early 1970s mostly biopolymers such as DNA were studied and often two separate relaxations were observed which were then attributed to internal relaxations [197-202]. During the past twenty years numerous studies on synthetic polyelectrolytes (NaPSS, NaPMA, NaPAA, QPVP), proteins (BSA, PLL), polynucleotides (DNA, RNA) and charged polysaccharides (heparin, chondroitin-6-sulfate, proteoglycan hyal-onurate) have been performed. The dynamical behaviour of all these polymers exhibits common features which are attributed to the ionic character of the polyelectrolytes. So far, most studies have focused on the dependence of the apparent diffusion coefficient on polyelectrolyte concentration, salt concentra-... 

This protein can be mixed in the S5m.thetic material such as in aldehyde treated albumin natural rubber, coated over plastic material, or it can be in natural tissue. Not only protein but probably other biological components such as polysaccharides (heparin), have a similar effect. 

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