Divalent antigen

Antigenic divalent and multivalent conjugates per se, formed by polymerization of the drug or by chemical reactions between the drug and a pharmaceutical adjuvant or an additive ... 

Supramolecular Formation of Antibodies with Divalent Antigens 244... 

Here, we describe the design and preparation of antibody supramolecular complexes and their application to a highly sensitive detection method. The complex formation between antibodies (IgG) and multivalent antigens is investigated. When an antibody solution is mixed with divalent antigen, a linear or cyclic supramolecule forms [26-29]. With trivalent antigens, the antibody forms network structures. These supramolecular formations are utilized for the ampH-fication of detection signals on the biosensor techniques. 

Fig. 3. Haptens and multivalent antigens prepared in this syudy. The viologen derivative, 4,4 -bipyridinium, l-(carboxypentyl)-l -methyl-dichloride (1), divalent antigen 2, and trivalent antigen 3. Anti-porphyrin antibodies were elicited for [5-(4-carboxyphenyl)-10,15,20-tris-(4-methylpyridyl)]porphine (3MPylC) or meso-tetrakis(4-carboxyphenyl)porphine (TCPP). meso-Tetrakis(4-methylpyridyl)porphine (TMPyP) was used to investigate the specificity of the antibody dendrimer for porphyrins...

Scheme 1. Complex formation of antibodies (IgG) with divalent antigens...

An enhancement of SPR signal intensity was observed by the addition of the antibody to the divalent antigen-antibody complex immobilized onto the surface of the sensor chip, indicating the formation of linear supramolecules. An amplification method of the detection signals for a target molecule has been... 

The antiproliferative effects of arsenic are well documented. In vitro both divalent and pentavalent arsenicals inhibit murine [28] and bovine [18] phytohemaglutinin (PHA)-stimulated lymphoproliferation at concentrations of > 3 pM. Lymph node cells from arsenic treated, FTTC-sensitized mice displayed reduced lymphoproliferation in response to Con A, suggesting that the mechanism of antigen processing/presentation may be altered by arsenic exposure, inhibiting T-cell responsiveness [29], However, in vivo... 

Other adhesion receptors that are structurally and functionally related include the receptors for fibronectin, vitronectin, platelet glycoproteins 13b and Ilia and the VLA (very-late antigen) series. All molecules involved in adhesion recognise the RGD motif and require the divalent cations Ca2+ and Mg2+ for binding. All are dimers of glycosylated proteins with relative molecular masses 95-190 kDa. There is also some sequence homology between the /J-chain (CD18) and one chain of the fibronectin receptor. 

An IgG-antibody against an individual ribosomal protein binds specifically only to this protein in a ribosomal subunit. Since the antibody is divalent it can form a bridge between the identical proteins in two subunits, leading to a dimer that can be examined under Ae electron microscope. The location of the bound antibody on the subunit surface can be determined, defining the position of the antigenic determinant of a particular protein. The method relies on the fact that IgG-antibodies are able to react with specific proteins within the intact ribosomal subunits and that both subunits have discernible shapes with recognizable morphological landmarks. 

Fujisawa, K., Tani, P, and McMillan, R., Platelet-associated antibody to glycoprotein llb/Illa from chronic immune thrombocytopenia purpura patients often binds to divalent cation-dependent antigens. Blood l, 1284-1289 (1993). 

Antigens and their corresponding antibodies precipitate by cross-linking to form an insoluble network. Polysaccharides have multiple, repetitive immunodeterminants and virtually none have demonstrable tertiary structure in solution (except, perhaps, under viscous stress). The number of these immunodeterminant groupings on each macromolecule is large. In the case of dextran, for instance, there are several thousand of them (if the dextran has a molecular weight of several million), even if the determinant involves the hep-tasaccharide. There is, thus, ample opportunity to form a precipitating, crosslinked complex with divalent (or polyvalent) antibody molecules. 

It should also be noted that the valency of binding at equilibrium may also be influenced by antibody concentration (2). Thus, high divalent antibody concentrations drive binding to a predominantly monovalent state, whereas at lower concentrations, the binding may be predominantly divalent this obviously varies the antigen-antibody stoichiometry from near 2.1 to approaching 1 1. The best compromise when this effect is in operation may be to use an antibody concentration on the initial plateau of a saturation curve. Increases in... 

The dissociation rate constant of an antibody-antigen interaction is characteristic of individual antibodies, but as discussed above, the rate at which antibody falls off the cell also depends on the valency of binding. Monovalent dissociation rates are faster than divalent dissociation rates, and the reassociation of a divalent interaction (i.e., of an antibody already bound by one binding site) is favored in comparison with monovalent association from the fluid phase. This avidity effect means that divalently bound fluorochrome-labeled antibodies are shed more slowly when fluid-phase antibody is removed by washing. 

Roe, R., Robins, R. A., Laxton, R R., and Baldwin, R W (1985) Kinetics of divalent monoclonal antibody binding to tumor cell surface antigens using flow cytometry—standardization and mathematical analysis Mol Immunol. 22, 11—21... 

A unique synthetic molecule that can be used as a carrier is the so-called multiple antigenic peptide (MAP) (Tam, 1988 Bosnetteta/., 1988). The MAP core structure is composed of a scaffolding of sequential levels of poly-L-lysine. The matrix is constructed from a divalent lysine compound to which two additional levels of lysine are attached. The final MAP compound consists of a symmetrical, octavalent primary... 

This method is further divided into two major types. One type is competitive ELISA, which can be used for the analysis of both hapten and macromolecule the other is noncompetitive sandwich-type ELISA, which is only used for divalent and multivalent antigens. Two major types, i.e., direct competitive ELISA (dC-ELISA) and indirect competitive ELISA (inC-ELISA), are used most commonly in food analysis. 

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