Heavy polypeptide chain

The antibodies are similar in structure to other globulin proteins which are present in serum of vertebrates [9], The antibody molecule consists of two light polypeptide chains and two heavy polypeptide chains [10]. The amino acids are present in all the chains but the number of residues and the sequence will vary in different antibody multiforms [9], Light chains contain approximately 220 amino add residues and heavy chains about 450 residues. The complete sequence of the chains of human IgG myeloma protein has been determined by Edelman [11], The chains are held together in the unique conformational structure of the antibody molecule by a few covalent disulfide bonds between the chains and many electrostatic bonds between the amino groups of one chain and the hydroxyl groups of another chain. The covalent bonds are represented in Formula 1, 2 and 3 [peptide, disulfide and... 

All immunoglobulins have a number of structural features in common.2 They possess two light polypeptide chains, each with an approximate molecular weight of 25 kDa, and two heavy polypeptide chains of 50 kDa each. These four chains are bound together in a single antibody molecule by disulfide bonds, and form a Y-shape with a central axis of symmetry (Fig. 5.2). The two halves of a natural immunoglobulin are identical. 

Also see color figure color coding is as the same as indicated in Fig. 35-7.) Immunoglobulin classes. The five immunoglobulin classes are determined by the amino acid sequences of the constant regions of the heavy polypeptide chains (see Table 35-2). 

All immunoglobulins have the same basic structure and consist of two identical light and two identical heavy polypeptide chains, held together by disulphide bridges (Fig. 1). The light chains may be cither of two types kappa or lambda. The heavy chains may be of five types alpha, gamma, delta, epsilon and mu. The immunoglobulins are named after their heavy chain type, as IgA. IgG. IgD. IgE and IgM. 

Comparison of Amino Acid Composition among Immunoglobulin Heavy Polypeptide Chains of Vertebrate Species ... 

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