Biomaterial Database

Flexibility of human IgG subclasses. 1997

K H Roux, and L Strelets, and T E Michaelsen

Department of Biological Science, Structural Biology Program, Florida State University, Tallahassee 32306, USA. roux@bio.fsu.edu

A variable region (Id)-matched set of genetically engineered human IgG1, -2, -3, and -4 subclass molecules was analyzed by electron microscopy for hinge-mediated differences in flexibility. The hinge-mediated bending was studied, as was the ability of the subclasses to form immune complexes with two anti-Id mAbs. The data show that the rank order (most to least flexible) of the IgG subclasses for hinge-folding mode of flexibility between Fab arms is IgG3 > IgG1 > IgG4 > IgG2. The mean Fab-Fab angles for the subclasses are IgG3, 136 degrees; IgG4, 128 degrees; IgG2, 127 degrees; and IgG1, 117 degrees. Fab-Fc angles were similarly analyzed. By sampling of equimolar mixtures of Id-bearing IgGs and each of two anti-Id mAb after incubation over time (1.5 min to 3.5 h), different kinetic profiles of immune complex formation of defined geometry were documented. Both anti-Id mAbs displayed unique kinetic profiles when complexed with the four IgG subclass molecules but also shared important features. Most notable was the higher propensity to form closed bivalent ring Id-anti-Id dimers with IgG3 than with IgG2 and IgG4. IgG1 was intermediate in its ability to form such dimers.

UI	MeSH Term	Description	Entries
D007074	Immunoglobulin G	The major immunoglobulin isotype class in normal human serum. There are several isotype subclasses of IgG, for example, IgG1, IgG2A, and IgG2B.	Gamma Globulin, 7S,IgG,IgG Antibody,Allerglobuline,IgG(T),IgG1,IgG2,IgG2A,IgG2B,IgG3,IgG4,Immunoglobulin GT,Polyglobin,7S Gamma Globulin,Antibody, IgG,GT, Immunoglobulin
D007130	Immunoglobulin Idiotypes	Unique genetically-controlled determinants present on ANTIBODIES whose specificity is limited to a single group of proteins (e.g., another antibody molecule or an individual myeloma protein). The idiotype appears to represent the antigenicity of the antigen-binding site of the antibody and to be genetically codetermined with it. The idiotypic determinants have been precisely located to the IMMUNOGLOBULIN VARIABLE REGION of both immunoglobin polypeptide chains.	Idiotypes, Immunoglobulin,Ig Idiotypes,Idiotype, Ig,Idiotype, Immunoglobulin,Idiotypes, Ig,Ig Idiotype,Immunoglobulin Idiotype
D007135	Immunoglobulin Variable Region	That region of the immunoglobulin molecule that varies in its amino acid sequence and composition, and comprises the binding site for a specific antigen. It is located at the N-terminus of the Fab fragment of the immunoglobulin. It includes hypervariable regions (COMPLEMENTARITY DETERMINING REGIONS) and framework regions.	Variable Region, Ig,Variable Region, Immunoglobulin,Framework Region, Immunoglobulin,Fv Antibody Fragments,Fv Fragments,Ig Framework Region,Ig Variable Region,Immunoglobulin Framework Region,Immunoglobulin Fv Fragments,Immunoglobulin V,Antibody Fragment, Fv,Antibody Fragments, Fv,Fragment, Fv,Fragment, Fv Antibody,Fragment, Immunoglobulin Fv,Fragments, Fv,Fragments, Fv Antibody,Fragments, Immunoglobulin Fv,Framework Region, Ig,Framework Regions, Ig,Framework Regions, Immunoglobulin,Fv Antibody Fragment,Fv Fragment,Fv Fragment, Immunoglobulin,Fv Fragments, Immunoglobulin,Ig Framework Regions,Ig Variable Regions,Immunoglobulin Framework Regions,Immunoglobulin Fv Fragment,Immunoglobulin Variable Regions,Regions, Immunoglobulin Variable,Variable Regions, Ig,Variable Regions, Immunoglobulin
D007140	Immunoglobulin Fab Fragments	Univalent antigen-binding fragments composed of one entire IMMUNOGLOBULIN LIGHT CHAIN and the amino terminal end of one of the IMMUNOGLOBULIN HEAVY CHAINS from the hinge region, linked to each other by disulfide bonds. Fab contains the IMMUNOGLOBULIN VARIABLE REGIONS, which are part of the antigen-binding site, and the first IMMUNOGLOBULIN CONSTANT REGIONS. This fragment can be obtained by digestion of immunoglobulins with the proteolytic enzyme PAPAIN.	Fab Fragment,Fab Fragments,Ig Fab Fragments,Immunoglobulins, Fab Fragment,Fab Immunoglobulin Fragments,Immunoglobulin Fab Fragment,Immunoglobulins, Fab,Fab Fragment Immunoglobulins,Fab Fragment, Immunoglobulin,Fab Fragments, Immunoglobulin,Fragment Immunoglobulins, Fab,Fragment, Fab,Immunoglobulin Fragments, Fab
D007143	Immunoglobulin Heavy Chains	The largest of polypeptide chains comprising immunoglobulins. They contain 450 to 600 amino acid residues per chain, and have molecular weights of 51-72 kDa.	Immunoglobulins, Heavy-Chain,Heavy-Chain Immunoglobulins,Ig Heavy Chains,Immunoglobulin Heavy Chain,Immunoglobulin Heavy Chain Subgroup VH-I,Immunoglobulin Heavy Chain Subgroup VH-III,Heavy Chain Immunoglobulins,Heavy Chain, Immunoglobulin,Heavy Chains, Ig,Heavy Chains, Immunoglobulin,Immunoglobulin Heavy Chain Subgroup VH I,Immunoglobulin Heavy Chain Subgroup VH III,Immunoglobulins, Heavy Chain
D007147	Immunoglobulin Light Chains	Polypeptide chains, consisting of 211 to 217 amino acid residues and having a molecular weight of approximately 22 kDa. There are two major types of light chains, kappa and lambda. Two Ig light chains and two Ig heavy chains (IMMUNOGLOBULIN HEAVY CHAINS) make one immunoglobulin molecule.	Ig Light Chains,Immunoglobulins, Light-Chain,Immunoglobulin Light Chain,Immunoglobulin Light-Chain,Light-Chain Immunoglobulins,Chains, Ig Light,Chains, Immunoglobulin Light,Immunoglobulins, Light Chain,Light Chain Immunoglobulins,Light Chain, Immunoglobulin,Light Chains, Ig,Light Chains, Immunoglobulin,Light-Chain, Immunoglobulin
D002460	Cell Line	Established cell cultures that have the potential to propagate indefinitely.	Cell Lines,Line, Cell,Lines, Cell
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D000888	Antibodies, Anti-Idiotypic	Antibodies which react with the individual structural determinants (idiotopes) on the variable region of other antibodies.	Anti-Antibodies,Anti-Idiotype Antibodies,Antibodies, Internal Image,Antigamma Globulin Antibodies,Antiglobulins,Anti Antibodies,Anti-gamma Globulin Antibodies,Anti Idiotype Antibodies,Anti gamma Globulin Antibodies,Anti-Idiotypic Antibodies,Antibodies, Anti,Antibodies, Anti Idiotypic,Antibodies, Anti-Idiotype,Antibodies, Anti-gamma Globulin,Antibodies, Antigamma Globulin,Globulin Antibodies, Anti-gamma,Globulin Antibodies, Antigamma,Image Antibodies, Internal,Internal Image Antibodies