Carbohydrates macromolecular substances

AFFINITY CHROMATOGRAPHY OF MACROMOLECULAR SUBSTANCES ON ADSORBENTS BEARING CARBOHYDRATE LIGANDS... 

Affinity adsorbents having carbohydrate ligands have been used for the isolation and purification of many types of macromolecular substances. To illustrate, several types of antibodies, enzymes, lectins, and myeloma proteins have been obtained in highly purified form. All of the substances that have been purified by this procedure exhibit specificity for a particular carbohydrate moiety. It is the purpose of this article to assemble information on the methods for preparing affinity adsorbents having carbohydrate ligands, and to illustrate the use of these adsorbents for the purification of representative, macromolecular substances. 

In addition to water and inorganic solids (salts dissolved in cell fluids, shells, and bones), organisms consist of a mix of organic substances. Some of these are macromolecules (e.g., globular proteins, cellulose). Some combine to form subcellular and tissue structures built with combinations of lipids, proteins, carbohydrates, and some specialized polymers like cutin or lignin (Fig. 10.2). These diverse organic materials cause organisms to have diverse macromolecular, cellular, and tissue portions that may be apolar, monopolar, and/or bipolar. 

Homogeneous, transparent solutions of proteins, carbohydrates, and other compounds can separate into two layers, one depleted and one enriched with these compounds. The process of separation of macromolecules into discrete entities is termed coacervation. The layer rich in molecules of the dissolved substance, referred to as the coacervate layer, actually consists of liquid "drops" or spherical microcapsules. The equilibrium liquid, which is the medium adjoining the coacervate layer, always contains less substance than the original solutions. The discrete liquid droplets resulting from macromolecular interactions might be made to serve as pseudocells from which pseudo tissues might be derived to constitute a restructured food. 

Plasma lipoproteins are macromolecular complexes of such chemically diverse substances as proteins, various kinds of lipids and, to minor proportions, carbohydrates. They serve primarily as transport vehicles for lipids in the aqueous environment of blood and lymph and represent an enormously broad spectrum of compostions and particle sizes. Traditionally lipoproteins are classified upon the operationally useful characteristic of buoyant density initiated by the ultracentrifugal separation studies by DeLalla and Gofman (1954) (Table 1). A biochemically more specific nomenclature was pioneered by Alaupovic (1972), whereby lipoprotein families are defined by their specific apolipoproteins. This concept of lipoprotein families has proven particularly useful in relating certain biochemical functions of individual lipoprotein classes to their apoproteins. 

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