Immunoglobulins heavy chains

Delassus, S., et al. Ontogeny of the heavy chain immunoglobulin repertoire in fetal liver and bone marrow, J. Immunol., 160, 3274, 1998. 

Heavy chain immunoglobulin G2 variable region [synthetic construct] ... 

The messenger RNA coding for mouse heavy chain immunoglobulin has been isolated from myeloma cells [250]. 

Stevens, R.H., Williamson, A.R. Isolation of messenger RNA coding for mouse heavy-chain immunoglobulin. Proc. nat. Acad. Sci. (Wash.) 70, 1127-1131 (1973)... 

The basic structure of all immunoglobulin (Ig) molecules comprises two identical light chains and two identical heavy chains linked together by disulfide bonds (Figure IS.2a). There are two different classes, or isotypes, of light chains, X and k, but there is no known functional distinction between them. Heavy chains, by contrast, have five different isotypes that divide the immunoglobulins into different functional classes IgG, IgM, IgA, IgD, and IgE, each with different effector properties in the elimination of antigen... 

In this chapter we will discuss immunoglobulins of the IgG class, which is the major type of immunoglobulin in normal human serum, and which has the simplest structure. Each chain of an IgG molecule is divided into domains of about 110 amino acid residues. The light chains have two such domains, and the heavy chains have four. 

The most remarkable feature of the antibody molecule is revealed by comparing the amino acid sequences from many different immunoglobulin IgG molecules. This comparison shows that between different IgGs the amino-terminal domain of each polypeptide chain is highly variable, whereas the remaining domains have constant sequences. A light chain is thus built up from one amino-terminal variable domain (Vl) and one carboxy-terminal constant domain (Cl), and a heavy chain from one amino-terminal variable domain (Vh), followed by three constant domains (Chi, Ch2. and Chs). 

The genes for MHC molecules, unlike immunoglobulin genes, do not undergo rearrangements to create structural diversity. The Pzm light chain is invariant, but the class I MHC heavy chain is the most genetically polymorphic... 

IgG antibody molecules are composed of two light chains and two heavy chains joined together by disulfide bonds. Each light chain has one variable domain and one constant domain, while each heavy chain has one variable and three constant domains. All of the domains have a similar three-dimensional structure known as the immunoglobulin fold. The Fc stem of the molecule is formed by constant domains from each of the heavy chains, while two Fab arms are formed by constant and variable domains from both heavy and light chains. The hinge region between the stem and the arms is flexible and allows the arms to move relative to each other and to the stem. 

Molecular chaperone (relative molecular mass 78 K) found in the lumen of the ER. BiP is related to the Hsp70 family of heat-shock proteins and was originally described as immunoglobulin heavy chain binding protein. 

Chaperones. Figure 2 The multiple roles of BiP in the biogenesis of the secretory proteins. BiP, immunoglobulin heavy chain binding protein ER, endoplasmic reticulum ERAD, ER-associated degradation ERj, resident ER protein with J-domain Sec61, core subunit of the protein translocase UPR, unfolded protein response that involves several signal transduction pathways that are activated in order to increase the biosynthetic capacity and decrease the biosynthetic burden of the ER... 

Haas, LG. Meo, T. (1988). cDNA cloning of the immunoglobulin heavy chain binding protein. Proc. Natl, Acad. Sci. USA 85,2250-2254. 

All Immunoglobulins Contain a Minimum of Two Light Two Heavy Chains... 

The Five Types of Heavy Chain Determine Immunoglobulin Class... 

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