constant region

American  

noun

1. Immunology. the part of the polypeptide sequence in a heavy or light chain of an antibody forming the C-terminal portion of the chain and is the same for all members of the class it specifies. Compare variable region.

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constant region Scientific  

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

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