Biomaterial Database

Cooperative binding of a complement component to antigen-antibody complexes. III. Complexes containing IgM antibodies. 1976

C Y Kuo, and J J Thompson, and L G Hoffmann

The first component of guinea pig complement (C1)2) is bound in a cooperative manner to antigen-antibody complexes containing rabbit IgM antibodies, as was previously shown to be the case for IgG antibodies. The shape of the binding curves is consistent with an allosteric mechanism involving clusters of 10 interacting C1 binding sites. Similar results were obtained with IgM antibodies against an artificial hapten and against a natural constituent of the erythrocyte membrane.

UI	MeSH Term	Description	Entries
D007075	Immunoglobulin M	A class of immunoglobulin bearing mu chains (IMMUNOGLOBULIN MU-CHAINS). IgM can fix COMPLEMENT. The name comes from its high molecular weight and originally was called a macroglobulin.	Gamma Globulin, 19S,IgM,IgM Antibody,IgM1,IgM2,19S Gamma Globulin,Antibody, IgM
D009578	Nitrobenzenes	BENZENE derivatives carrying nitro group substituents.
D011485	Protein Binding	The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.	Plasma Protein Binding Capacity,Binding, Protein
D003165	Complement System Proteins	Serum glycoproteins participating in the host defense mechanism of COMPLEMENT ACTIVATION that creates the COMPLEMENT MEMBRANE ATTACK COMPLEX. Included are glycoproteins in the various pathways of complement activation (CLASSICAL COMPLEMENT PATHWAY; ALTERNATIVE COMPLEMENT PATHWAY; and LECTIN COMPLEMENT PATHWAY).	Complement Proteins,Complement,Complement Protein,Hemolytic Complement,Complement, Hemolytic,Protein, Complement,Proteins, Complement,Proteins, Complement System
D003172	Complement C1	The first complement component to act in the activation of CLASSICAL COMPLEMENT PATHWAY. It is a calcium-dependent trimolecular complex made up of three subcomponents: COMPLEMENT C1Q; COMPLEMENT C1R; and COMPLEMENT C1S at 1:2:2 ratios. When the intact C1 binds to at least two antibodies (involving C1q), C1r and C1s are sequentially activated, leading to subsequent steps in the cascade of COMPLEMENT ACTIVATION.	C1 Complement,Complement 1,Complement Component 1,C1, Complement,Complement, C1,Component 1, Complement
D005577	Forssman Antigen	A glycolipid, cross-species antigen that induces production of antisheep hemolysin. It is present on the tissue cells of many species but absent in humans. It is found in many infectious agents.	Antigen, Forssman
D006241	Haptens	Small antigenic determinants capable of eliciting an immune response only when coupled to a carrier. Haptens bind to antibodies but by themselves cannot elicit an antibody response.	Hapten,Contact-Sensitizing Agents,Agents, Contact-Sensitizing,Contact Sensitizing Agents
D000494	Allosteric Regulation	The modification of the reactivity of ENZYMES by the binding of effectors to sites (ALLOSTERIC SITES) on the enzymes other than the substrate BINDING SITES.	Regulation, Allosteric,Allosteric Regulations,Regulations, Allosteric
D000936	Antigen-Antibody Complex	The complex formed by the binding of antigen and antibody molecules. The deposition of large antigen-antibody complexes leading to tissue damage causes IMMUNE COMPLEX DISEASES.	Immune Complex,Antigen-Antibody Complexes,Immune Complexes,Antigen Antibody Complex,Antigen Antibody Complexes,Complex, Antigen-Antibody,Complex, Immune,Complexes, Antigen-Antibody,Complexes, Immune