antibody (rus. антитело) — a protein (immunoglobulin), synthesised by B-lymphocytes in animals in response to the introduction of a foreign substance and having a specific affinity for the substance.

Description

Antibodies are used by the immune system to identify and neutralize foreign objects. A foreign molecule that causes the formation of an antibody is called an antigen, and its site that specifically binds to an antibody is called an antigenic determinant. Proteins, polysaccharides and nucleic acids are effective antigens. Small molecules do not induce an antibody response. The protective effect of antibodies is widely used in the treatment and prevention of infectious diseases. Antigen-antibody reactions are used in the treatment and diagnostics of various diseases, for isolation and purification of biological substances. In nanomedicine, antibodies against human antigens can be used for the targeted delivery of nanoparticles to specific cell populations (including molecular vectors). For example, magnetic nanoparticles, conjugated with antibodies to tumour markers may be used for diagnostics by magnetic resonance imaging and for hyperthermia therapy (in the latter case, the particles are heated by an external magnetic field and cause local cell death).

Illustrations

Structure of an antibody (G2a immunoglobulin). the antibody is made up of four polypeptide chains

Structure of an antibody (G2a immunoglobulin). the antibody is made up of four polypeptide chains - two light and two heavy chains. Light chains binds with foreign antigens, which is why they have an unstable structure and are flexible. By contrast, heavy chains have a relatively stable structure while they support the light chains and interact with the immune system of a host organism.


Author

  • Kurochkin Ilya N.

Sources

  1. B. Glick, J. Pasternak. Molecular Biotechnology: Principles and Applications of Recombinant DNA. — 3rd ed. Sigma Publishing, 2003, 784 pp.
  2. Lubert Stryer. Biochemistry. — W. H. Freeman, 1981. — 949 pp.
  3. Jain K.K. The Handbook of Nanomedicine. — Humana Press, 2008. — 403 p.

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