Antibody: Difference between revisions
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<StructureSection load='1hzh' size='450' side='right' scene='Antibody/1hzh_starting_scene/3' caption=''> | |||
'''Antibodies''', also known as '''Immunoglobulins''' (Ig) are gamma globulin proteins, primarily found in the blood of vertebrates. These [[glycoproteins]] serve as a critical component of the immune system when the host fails to activate alternative compliment pathways or phagocytic cells in response to invading microorganisms or other [http://en.wikipedia.org/wiki/Antigen antigens]. The incredible specificity with which immunoglobulins bind to an antigen is based upon structural complementarity between the antigen and antibody <scene name='Antibody/1hzh_heavy_chains/1'>heavy </scene>and <scene name='Antibody/1hzh_light_chains/1'>light chains </scene>. It is this specificity that has made <scene name='Antibody/1hzh_starting_scene/3'>antibodies</scene> a critical component in laboratory and medical research. See more in [[IgA]], [[Monoclonal Antibody]]. For Anti-HIV Fab see [[Human Fab PG16]]. | '''Antibodies''', also known as '''Immunoglobulins''' (Ig) are gamma globulin proteins, primarily found in the blood of vertebrates. These [[glycoproteins]] serve as a critical component of the immune system when the host fails to activate alternative compliment pathways or phagocytic cells in response to invading microorganisms or other [http://en.wikipedia.org/wiki/Antigen antigens]. The incredible specificity with which immunoglobulins bind to an antigen is based upon structural complementarity between the antigen and antibody <scene name='Antibody/1hzh_heavy_chains/1'>heavy </scene>and <scene name='Antibody/1hzh_light_chains/1'>light chains </scene>. It is this specificity that has made <scene name='Antibody/1hzh_starting_scene/3'>antibodies</scene> a critical component in laboratory and medical research. See more in [[IgA]], [[Monoclonal Antibody]]. For Anti-HIV Fab see [[Human Fab PG16]]. | ||
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[[Image:230px-B cell activation2.png|270px|left|thumb| Production of Antibodies by Plasma Cells]] | [[Image:230px-B cell activation2.png|270px|left|thumb| Production of Antibodies by Plasma Cells]] | ||
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==Cellular Basis of Antibody Production== | ==Cellular Basis of Antibody Production== | ||
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==Structure of the Immunoglobulin== | ==Structure of the Immunoglobulin== | ||
<scene name='Antibody/1igt_starting_scene/3'>Refined Structure of an Intact IgG2a Monoclonal Antibody</scene> ([[1igt]]). | |||
The basic functional unit of an antibody is an immunoglobulin monomer, but antibodies secreted from plasma cells are typically dimeric with occasional higher order structures. Typical secreted antibodies have a basic four-peptide structure of two identical <scene name='Antibody/1igt_heavy_chains/1'>heavy chains </scene>and two identical <scene name='Antibody/1igt_light_chains/1'>light chains</scene> joined together by interchain <scene name='Antibody/1igt_disulfide_bonds/2'>disulfide bonds</scene>, forming a “Y” shaped molecule. The disulfide bonds are positioned within a flexible region called the <scene name='Antibody/1igt_hinge_region/1'>hinge region</scene>, which seperates the lobes of the antibody from one another and provides ample flexibility to bind antigens effectively. <ref name="Roit" /> Each domain (2 heavy and 2 light) contain between 70-110 amino acids and are classified into different categories according to size and function. <ref>PMID:10545762</ref> Both domains, heavy and light, contain variable and constant regions that are crucial to antibody function. <ref>PMID:107164</ref> | The basic functional unit of an antibody is an immunoglobulin monomer, but antibodies secreted from plasma cells are typically dimeric with occasional higher order structures. Typical secreted antibodies have a basic four-peptide structure of two identical <scene name='Antibody/1igt_heavy_chains/1'>heavy chains </scene>and two identical <scene name='Antibody/1igt_light_chains/1'>light chains</scene> joined together by interchain <scene name='Antibody/1igt_disulfide_bonds/2'>disulfide bonds</scene>, forming a “Y” shaped molecule. The disulfide bonds are positioned within a flexible region called the <scene name='Antibody/1igt_hinge_region/1'>hinge region</scene>, which seperates the lobes of the antibody from one another and provides ample flexibility to bind antigens effectively. <ref name="Roit" /> Each domain (2 heavy and 2 light) contain between 70-110 amino acids and are classified into different categories according to size and function. <ref>PMID:10545762</ref> Both domains, heavy and light, contain variable and constant regions that are crucial to antibody function. <ref>PMID:107164</ref> | ||
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[[Image:VDJ recombination.png|400px|left|thumb| Image of V(D)J Recombination]] | [[Image:VDJ recombination.png|400px|left|thumb| Image of V(D)J Recombination]] | ||
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<scene name='Antibody/Rituxan_starting_scene/1'>Crystal structure of Rituximab Fab in complex with an epitope peptide</scene> ([[2osl]]). | |||
=== Antibody Diversity === | === Antibody Diversity === | ||
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[[Image:FluorescentCells.jpg|300px|right|thumb| Direct Immuno fluorescence Antibody labeling]] | [[Image:FluorescentCells.jpg|300px|right|thumb| Direct Immuno fluorescence Antibody labeling]] | ||
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==Antibody Applications== | ==Antibody Applications== | ||
Detection of particular antibodies is very common in medical diagnostic testing. Numerous biochemical assays exist to detect whether antibodies for specific antigens are present in the blood or other bodily fluids such as antibodies against [http://en.wikipedia.org/wiki/Lyme_disease Lyme disease] or [http://en.wikipedia.org/wiki/HIV HIV], etc. Another common medical test involving antibodies is blood type detection in which an individual’s blood is screened against anti-A and anti-B antibodies to determine the identity of that individual’s [http://en.wikipedia.org/wiki/Blood_type blood antigen type]. <ref>PMID:13477267</ref> | Detection of particular antibodies is very common in medical diagnostic testing. Numerous biochemical assays exist to detect whether antibodies for specific antigens are present in the blood or other bodily fluids such as antibodies against [http://en.wikipedia.org/wiki/Lyme_disease Lyme disease] or [http://en.wikipedia.org/wiki/HIV HIV], etc. Another common medical test involving antibodies is blood type detection in which an individual’s blood is screened against anti-A and anti-B antibodies to determine the identity of that individual’s [http://en.wikipedia.org/wiki/Blood_type blood antigen type]. <ref>PMID:13477267</ref> | ||