Immunoglobulin hypervariable regions

Chothia C, A M Lesk, A Tramontano, M Levitt, S Smith-Gill, G Air, S Sheriff, E A Padlan and D Davies 1989. Conformations of Immunoglobulin Hypervariable Regions. Nature 342 877-883. 

C Chothia, AM Lesk. Canonical structures for the hypervariable regions of immunoglobulins. J Mol Biol 196 901-917, 1987. 

T-cell receptors have variable and constant immunoglobulin domains and hypervariable regions... 

Chothia, C., et al. Conformations of immunoglobulin hypervariable regions. Nature 343 877-883, 1989. 

In summary, for all the immunoglobulin molecules within one class, the amino acid sequence in the constant region of the chains is identical the massive number of different molecules within each class is accounted for by the amino acid sequences in the variable and hypervariable regions of both the light and heavy chains. 

Figure 33.7. Immunoglobulin Sequence Diversity. A plot of sequence variability as a function of position along the sequence of the amino-terminal immunglobulin domain of the H chain of human IgG molecules. Three regions (in red) show remarkably high levels of variability. These hypervariable regions correspond to three loops in the immunoglobulin domain structure. [After R. A. Goldsby, T. J. Kindt, and B. A. Osborne, Kuby Immunology, 4th ed. (W. H. Freeman and Company, 2000), p. 91.]...

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