Complementarity-determining region: Difference between revisions

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A single chain antibody fragment showing the positions of the three complementarity determining regions, CDR1, CDR2 and CDR3

Complementarity determining regions (CDR), are regions within antibodies or T cell receptors where these proteins complement an antigen's shape. Thus, CDRs determine the protein's affinity and specificity for specific antigens. The CDRs are the most variable part of the molecule, and contribute to the diversity of these molecules, allowing the antibody (also known as an immunoglobulin) and the T cell receptor to recognize a vast repertoire of antigens.

CDRs are composed of three variable regions (CDR1, CDR2, and CDR3) of amino acid sequence in immunoglobulins. CDR1 and CDR2 are found in the variable (V) domain, and CDR3 includes some of V, all of diverse (D) (heavy chains only) and joint (J), and some of the constant (C) domains. CDR3 is the most variable.

A hypervariable domain, known for its unusually high level of sequence variation, exists as a flexible loop in CDR1. The hypervariable loops from each domain are brought together to create the antigen-binding site and thus determines the molecule's specificity.^[1] Among these, CDR3 shows the greatest variability as it is encoded by a recombination of the VJ in the case of a light chain region and VDJ in the case of heavy chain regions.

References

^ Abbas AK and Lichtman AH (2003). Cellular and Molecular Immunology (5th ed. ed.). Saunders, Philadelphia. ISBN 0-7216-0008-5. {{cite book}}: |edition= has extra text (help)

External links

Complementarity+determining+regions at the U.S. National Library of Medicine Medical Subject Headings (MeSH)

[1] Abbas AK and Lichtman AH (2003). Cellular and Molecular Immunology (5th ed. ed.). Saunders, Philadelphia. ISBN 0-7216-0008-5. {{cite book}}: |edition= has extra text (help)

[1]

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 [[Image:ScFv-rotation.gif|right|300px|thumb|A single chain antibody fragment showing the positions of the three complementarity determining regions, CDR1, CDR2 and CDR3]]
-'''Complementarity determining regions''' (CDR), are [[antibody]] or [[T cell receptor]] ''regions'' where the molecule ''complements'' an antigen's conformation. Thus, CDRs determine the molecule's specificity and make contact with a specific antigen. CDR1 and CDR2 are found in the variable (V) domain, and CDR3 includes some of V, all of diverse (D) (heavy chains only) and joint (J), and some of the constant (C) domains. CDR3 is the most variable.
+'''Complementarity determining regions''' (CDR), are regions within [[antibody|antibodies]] or [[T cell receptor|T cell receptors]] where these proteins ''complement'' an [[antigen]]'s shape. Thus, CDRs determine the protein's affinity and specificity for specific antigens.  The CDRs are the most variable part of the molecule, and contribute to the diversity of these molecules, allowing the antibody (also known as an [[immunoglobulin]]) and the T cell receptor to recognize a vast repertoire of antigens.
-A ''hypervariable domain,'' known for its unusually high level of sequence variation, exists as a flexible loop in CDR1. The hypervariable loops from each domain are brought together to create the antigen-binding site and thus determines the molecule's specificity.
+CDRs are composed of three variable regions (CDR1, CDR2, and CDR3) of amino acid sequence in immunoglobulins. CDR1 and CDR2 are found in the variable (V) domain, and CDR3 includes some of V, all of diverse (D) (heavy chains only) and joint (J), and some of the constant (C) domains. CDR3 is the most variable.
+A ''hypervariable domain,'' known for its unusually high level of sequence variation, exists as a flexible loop in CDR1. The hypervariable loops from each domain are brought together to create the antigen-binding site and thus determines the molecule's specificity.<ref>{{cite book | author = Abbas AK and Lichtman AH | title = Cellular and Molecular Immunology | edition = 5th ed. | publisher =  Saunders, Philadelphia |year = 2003 |isbn = 0-7216-0008-5}}</ref> Among these, CDR3 shows the greatest variability as it is encoded by a recombination of the VJ in the case of a light chain region and [[V(D)J recombination|VDJ]] in the case of heavy chain regions.
 ==References==
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 ==External links==
 * {{MeshName|Complementarity+determining+regions}}
 [[Category:Amino acids]]
 [[Category:Immune system]]