ABSTRACT
Organic compounds including protein and non-protein fragments (the latter represent a prosthetic group) are called the conjugate proteins or proteids. Glycoproteids are biopolymers consisting of a protein and a carbohydrate fragments. Muconic compounds are belonged to these substances - the polymers including proteins, polysaccharides and lipids, linked by covalent and ionic bonds. Mucoproteids composed of proteins (the predominant component of the natural complex) and carbohydrates (oligo-or polysaccharides) are the components of mucous linings of the animal organs, blood and milk; mucopolysaccharides are the components of connective tissues, liver and lungs. Among glycoproteids are immunoglobulins (A, E, D, G, M), lg, produced by B-lymphocytes and plasmatic cells. Ig function as antibodies, which protect the organism from dangers of intervention of the aliensubstances - antigens. The structure of immunoglobulins is based on a dimer consisting of two light (L) and two heavy (H) polypeptide chains, to which oligosaccharide fragments are bound. lgM have five such fragments consisting of mannose and N-acetylglucosamine residues. The structures of lgA, lgE and lgD also include fucose, galactose and N-acetylneuraminic acid. Some immunoglobulins are freely disposed in the blood serum (IgE), intestinal and bronchial secretion, pituitary membrane (IgA) and so on; Ig(G, A, M, D and E) are found in the membrane (the surface) of B-lymphocytes.
