Polysaccharides acid and

Sephadex. Other carbohydrate matrices such as Sephadex (based on dextran) have more uniform particle sizes. Their advantages over the celluloses include faster and more reproducible flow rates and they can be used directly without removal of fines . Sephadex, which can also be obtained in a variety of ion-exchange forms (see Table 15) consists of beads of a cross-linked dextran gel which swells in water and aqueous salt solutions. The smaller the bead size, the higher the resolution that is possible but the slower the flow rate. Typical applications of Sephadex gels are the fractionation of mixtures of polypeptides, proteins, nucleic acids, polysaccharides and for desalting solutions. 

Polymers are examples of organic compounds. However, the main difference between polymers and other organic compounds is the size of the polymer molecules. The molecular mass of most organic compounds is only a few hundred atomic mass units (for reference, atomic hydrogen has a mass of one atomic mass unit). The molecular masses of polymeric molecules range from thousands to millions of atomic mass units. Synthetic polymers include plastics and synthetic fibers, such as nylon and polyesters. Naturally occurring polymers include proteins, nucleic acids, polysaccharides, and rubber. The large size of a polymer molecule is attained by the repeated attachment of smaller molecules called monomers. 

Volume 203. Molecular Design and Modeling Concepts and Applications (Part B Antibodies and Antigens, Nucleic Acids, Polysaccharides, and Drugs) Edited fey John J. Langone... 

S. Xu and M. Yonese, in Charge Densities and Nanoparticle Formation of Complexes Composed of Acid Polysaccharides and Protein, Nagoya, Japan, 1998, p. E1076. 

Big molecules of life include the proteins, nucleic acids, polysaccharides, and a few other more exotic constrncts of nature. Generally, it is the interactions between big molecules and small ones that nnderlie really interesting things taste or smeU or the beneficial actions of drugs, for example. 

The crude gum tragacanth is a mixture of the salt of a complex acid polysaccharide and a neutral polysaccharide composed principally of L-arabinose residues. Starch is also present in the gum. The acid character of this gum is due to units of D-galacturonic acid and not D-glucuronic acid and it is of interest to note that in its ability to form gels it resembles pectin and the plant mucilages, which also contain D-galacturonic acid. 

Hydrogen bonds and ionic, hydrophobic (Greek, water-fearing ), and van der Waals interactions are individually weak, but collectively they have a very significant influence on the three-dimensional structures of proteins, nucleic acids, polysaccharides, and membrane lipids. 

Fourteen chapters, each by a different author, cover (at an advanced level) the structure of water and its interactions with proteins, nucleic acids, polysaccharides, and lipids. 

In our study, formation of isoluble complexes between pectin, a heterogeneous mixture of a number of neutral and acidic polysaccharides, and lipoprotein was studied. The basic limitation with the formation of insoluble complexes is that it is difficult to quantitate the said interaction. Furthermore, the observed interaction between pectic polysaccharides and lipoprotein is at a pH which is not physiological. We, therefore, are attempting to study this interaction under physiological conditions and by use of buffer systems which are devoid of cations, in order to facilitate formation of soluble complexes. In addition, by using labelled pectic polysaccharides, studies resulting in the elucidation of kinetics, specificity and nature of the interaction between labelled pectic polysaccharides and lipoprotein will be performed. 

Cui and Mazza (1996) reported that neutral polysaccharides have a larger molecular size than acidic polysaccharides and flaxseed gum showed superior moisture retention properties compared to carboxymethylcellulose, Arabic, guar, and xanthan gums. Acidic polysaccharides show more shear... 

The separation of neutral and acidic polysaccharides, and of polysaccharide and nucleic acid, can be effected with cationic detergents separation of polysaccharide and protein is frequently made by the well established method of Sevag. ... 

A separation of the nucleic acid, polysaccharide and protein fractions of tuberculin was effected by the Tiselius electrophoretic technique, which was developed for large scale work in this field by Seibert and Watson. The polysaccharide was relatively immobile and thus was easily removed from the protein and nucleic acid. At pH 5.0 (or less), the nucleic acid and protein traveled in the electrophoretic tube as a single component. At higher pH values, the two tended to move independently. It was probable that some of the protein and nucleic acid was present as nucleoprotein. 

Calcified scales formed inside the Golgi and then extruded have so far only been found in coccolithophorids. In other forms, the matrix is formed in the Golgi but calcification takes place in the cytoplasm. In some cases, the plates of coccolithophorids calcify inside the T-shaped cisternae where the stem is associated with the Golgi stack while the scale is already forming with its future distal surface facing the stack. The scales of coccolithophorids always consist of two layers of a cellulose network of microfibrils radially and concentrically arranged. The outer layer of the scale is made up of acidic polysaccharides and small amounts of protein, probably containing hydroxy-... 

Three of the main active components of Echinacea, cichoric acid, polysaccharides, and alkylamides, were separated and tested at various doses in rats for phagocytic activity in alveolar macrophages and splenocytes. The alveolar macrophages from the group of rats treated with the alkylamides were the only cells to show any significant increases in phagocytic activity, phagocytic index, TNF-cx, and nitric oxide. None of the components tested had any activity on splenocytes (7). 

Dietary fibre consists of all components of plant cell walls not digested by human alimentary enzymes. Chemically, fibre is a mixture of cellulose, lignin, heteropoly-saccharides (hemicelluloses), acidic polysaccharides and pectin. In the colon, bacteria hydrolyse up to 15% of cellulose and 70-95% of other polysaccharides giving rise to volatile gases and low molecular weight fatty acids (acetic, butyric etc.) which have weak laxative activity. In addition the cellulosic and non-cellulosic polysaccharides are hydrophilic and absorb large amounts of fluid from the gut lumen, increasing in bulk as they do so. This is exactly the... 

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