constant region

1. The portion of the amino acid sequence of an antibody's heavy or light chains that determines the class of the antibody and does not vary within a given class. The constant region terminates in a free carboxyl group (COOH). Unlike the variable region, the constant region does not interact with antigens.

2. Compare variable region

Example Sentences

The FG loop structure5 of TCRβ’s constant region controls the lifetime of a TCR–pMHC bond and also the extension of the TCRαβ heterodimer when it transitions from a compact to an extended form under force during antigen recognition6,9.

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Targeted deletion of the IgA constant region in mice leads to IgA deficiency with alterations in expression of other Ig isotypes.

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