Hapten for

The reaction product 136 is not an appropriate hapten for generating catalytic antibody as it does not closely resemble the reaction intermediate 135. Antibody 1E9 was prepared against hapten 137, a stable analog of 135, and the catalyst promoted the Diels-Alder reaction with multiple (> 50) turnovers. 

Fig. 21 Cationic P( VI) hapten for biomimetic photo synthetic studies...

Another commonly used ELISA format is the immobilized antibody assay or direct competitive assay (Eigure 3). The primary anti-analyte antibody is immobilized on the solid phase and the analyte competes with a known amount of enzyme-labeled hapten for binding sites on the immobilized antibody. Eirst, the anti-analyte antibody is adsorbed on the microtiter plate wells. In the competition step, the analyte and enzyme-labeled hapten are added to microtiter plate wells and unbound materials are subsequently washed out. The enzyme substrate is then added for color production. Similarly to indirect competitive immunoassay, absorption is inversely proportional to the concentration of analyte. The direct competitive ELISA format is commonly used in commercial immunoassay test kits. 

Figure 8 Structure of immunogen haptens for pyrethroids with spacer arm attachment at the a-position of the alcohol moiety. Since the whole pyrethroid molecule is available for recognition by the antibody, assays resulting from these immunogens were selective for the parent pyrethroids...

A domino RCM of an ene-yne was also used by Granja and coworkers [250] for their synthesis of the B-bishomo-steroid analogue 6/3-70. Reaction of the substrate 6/3-69 with the ruthenium catalyst 6/3-13 led to 6/3-70 in 48% yield as a 6.5 l-mix-ture of the two C-10-epimers (Scheme 6/3.20). The aim of this study was to prepare haptenes for the production of catalytic monoclonal antibodies that could be used to study the mechanism of the physiologically important transformation of previtamin D3 into vitamin D3 [251]. 

In a further enterprise, compounds [63] and [64] (Fig. 24) were perceived as freely rotating haptens for application as TSAs for the same Diels-Alder addition. As expected, each proved capable of inducing both endo- and exo-adduct-forming abzymes. It can be noted that [63] produced more exo-catalysts (6 out of 7) whereas [64] favoured the production of endo-catalysts (7 out of 8), though it is difficult to draw any conclusion from this observation (Appendix entry 17.5) (Yli-Kauhaluoma et al., 1995). 

Fig. 9. Schematic representation of the noncompetitive immunoassay of triiodothyronine using a solid-phase immobilized hapten for masking an unoccupied antibody.

Figure 7.20 Examples of haptens for the creation of antibodies directed toward the 6-phosphor-ylserine tumor suppressive protein p53. ...

Phosphonates have been widely used as analogues of carboxylic acids. They have been particularly effective as analogues of tetrahedral transition states that occur in the course of enzyme-catalyzed reactions such as hydrolysis of the amide (peptide) bond. As such, they may be used as inhibitors of enzymes (e.g., 82, 83) or as haptens for producing antibodies that are catalytic (e.g., 84). A notable example is H203P— CH2—CH2—CH(—NH2)—COOH, which has effects that are likely to be due to its interference with glutamate as a neurotransmitter (85). 

Immunoadsorbents can be made with whole antigens or haptens. For example, Haber42 reported the preparation of a Diplococcus pneumoniae Type III immunoadsorbent. The capsular polysaccharide (S III) was p-nitrobenzylated to a low degree of substitution by the method of Avery and Goebel.43 The resultant ether was re-... 

Compoimd (35) has been synthesized to mimic the NADH/NAD 1 cofactor and product in the transition-state model (34) of hydride transfer in dehydrogenase enzymes.286 The intended use of (35) is to act as a hapten for the generation of catalytic antibodies with the potential to act as dehydrogenase mimics. 

To a solution of known titre antiserum is added a known concentration of radioactive or tracer hapten (antigen) and an aliquot of the plant extract. There will be a competition of the labelled hapten (added) and unlabelled (plant extract) hapten for the fixed number of antibody sites (antiserum of known titre) and this results in some of the labelled hapten being bound while the remainder remains free. The distribution of the radioactive hapten between the free and bound state will be a function of the amount of unlabelled hapten present in the assay tube. 

K. Balakrishnan, S. Q. Mehdi, and H. M. McConnell, Availability of dinitrophenylated lipid haptens for specific antibody binding depends on the physical properties of host bilayer membranes, J. Biol. 

First, an inert ligand is desirable because it allows the investigator to perform important preliminary experiments with ease. Binding measurements and assays of biological activity are straightforward and unusual experiments that might not be feasible with a chemically reactive molecule can be done. For example, photolabile molecules may be used as haptens for antibody production and the hapten-immunoglobulin interaction subsequently explored (Fleet et al., 1969). 

Figure 2. The structure of S-bioallethrin (1R, 3R, 4 S allethrin) and possible haptens for the formation of antigens for allethrin.

Pioneering work on immunochemical assays for pesticides involved the synthesis of haptens for DDT and malathion. Haas and Guardia (24) used the acid chlorides of malathion half ester and DDA (2,2-bis-[j)-chlorophenyl]acetic acid) for conjugation while Centeno et al. (25) used the anhydrides of DDA and malathion diacid (0,0-dimethyl S-[l,2-bis-carboxyethyl]phosphorodi-thioate). In retrospect, more specific antibodies of a higher titer may have been obtained had a spacer arm been used. 

M14. Monji, N., Malkus, H., and Castro, A., Maleimide derivative of hapten for coupling to enzyme A new method in enzyme immunoassay. Biochem. Biophys. Res. Commun. 85, 671-677 (1978). 

The aldol reaction catalyzed by Ab33F12 is outlined in Scheme 5.65. Regardless of the stereochemistry at C(2) of the aldehyde substrate shown (Scheme 5.65), its antibody catalyzed reaction with acetone resulted in a diastereoselective addition of acetone to the S/ -facc of the aldehyde. The products were formed with similar yields, and thus kinetic resolution was observed. However, the degree of facial stereochemical control of the reaction is surprising, since no stereochemical information was built into the hapten. For the... 

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