Kinetic Studies on Antibody–Hapten Reactions. II. Reactions with Antibodies and their Polypeptide Chains

1973 ◽  
Vol 51 (10) ◽  
pp. 1355-1364 ◽  
Author(s):  
K. A. Kelly ◽  
A. H. Sehon ◽  
A. Froese

Kinetic and equilibrium studies were performed on the reactions of the hapten ε-dinitrophenyl-lysine with specific intact antibodies, reduced, alkylated, and polyalanylated antibodies, and reduced, alkylated, and polyalanylated γ-chains. No reaction was detected between the hapten and light chains. The γ-chains were found to have 0.5 combining sites per chain, and thin layer gel chromatography revealed that they existed as monomers. The rate constant of association for the reaction of γ-chains with hapten was found to be almost 1000 times lower than that for the corresponding reaction with the parent antibody. Differences in the rate constants of dissociation were much less pronounced. These results suggested that the combining site in the separated γ-chain had undergone a change in conformation.

1973 ◽  
Vol 133 (4) ◽  
pp. 827-836 ◽  
Author(s):  
G. T. Stevenson

1. The binding of haptens by the polypeptide chains derived from two rabbit immunoglobulin G antibodies was examined by gel chromatography and equilibrium dialysis. 2. The γ chains were examined in a dilute sodium acetate buffer, pH5.4, in which they exist as a monodisperse solution of dimers; aggregation of the protein promoted by some haptens had to be avoided. These chains exhibited variable extents of binding, reflecting the specificities of the parent antibody molecules, usually with only small increments above the binding by γ chains from normal immunoglobulin G. 3. The light chains existed as an interconverting mixture of monomers and dimers in all buffers of near neutral pH that were examined. They bound small amounts of hapten, again broadly reflecting the specificities of the parent antibody molecules. 4. For both the γ and light chains the dimeric state appeared necessary for appreciable binding of hapten. Apparently in each case the partners in the dimer interact in a manner analogous to the γ chain–light chain interaction in the parent antibody molecule, to give a site analogous to the antibody site. This implies that the binding of antigens by isolated chains has a large fortuitous element, providing no reliable indication of their contributions to the original antibody sites.


1964 ◽  
Vol 42 (10) ◽  
pp. 2250-2255 ◽  
Author(s):  
D. M. Graham ◽  
R. L. Mieville ◽  
R. H. Pallen ◽  
C. Sivertz

Kinetic studies have been made of the addition of methanethiol to ethylene, propylene, and butene-2. The results obtained are consistent with the mechanism postulated for the isomerization reaction (1). The overall activation energy was found to be negative and could be explained in terms of two competing reactions of the adduct radical: thermal decomposition leading to [Formula: see text] and olefin and dehydrogenation of thiol yielding addition product. Only the ratio of the rate constants for these two reactions could be determined. The method of intermittent illumination was used to evaluate the termination rate constant for the combination of two [Formula: see text] radicals which was found to be (2.5 ± 0.7) × 1010 l mole−1 s−1.


1997 ◽  
Vol 325 (1) ◽  
pp. 177-182 ◽  
Author(s):  
Mokdad MEZNA ◽  
Francesco MICHELANGELI

Thimerosal, a thiol-reactive reagent, has been shown to increase the cytosolic Ca2+ concentration in a variety of cells by sensitizing inositol 1,4,5-trisphosphate (InsP3) receptors. Thimerosal can have both sensitizing (at concentrations of < 2 μM) and inhibitory (at concentrations of > 2 μM) effects on InsP3-induced Ca2+ release (IICR) from cerebellar microsomes. Transient kinetic studies were performed by employing a fluorimetric stopped-flow approach using fluo-3. IICR was found to be a bi-exponential process with a fast and a slow component. At a maximal InsP3 concentration (20 μM), the fast phase had a rate constant of 0.9 s-1 and the slow phase had a rate constant of 0.4 s-1. The amplitudes of the two phases were 60% and 40% respectively. When the rate constants for the two phases were plotted as Hill plots, the processes were found to be non-co-operative in both cases (Hill coefficient of 1.0), thus arguing for a simple mechanism linking InsP3 binding to channel opening. At a submaximal InsP3 concentration (0.2 μM), where the sensitizing effects of thimerosal are most pronounced, thimerosal increased the rate constants of both phases in a sigmoidal fashion, with a Hill coefficient of 4.0, suggesting that several cysteine residues (up to four) need to be modified in order for maximum sensitization to occur. The rate constants remained elevated even at thimerosal concentrations that inhibited IICR. The amplitude or extent of Ca2+ release was, however, elevated to a much greater extent in the slow phase, suggesting that the two phases respond differently. At maximal InsP3 concentrations, thimerosal has no effect upon the rate constants but inhibits the amplitude of Ca2+ release.


1983 ◽  
Vol 48 (5) ◽  
pp. 1358-1367 ◽  
Author(s):  
Antonín Tockstein ◽  
František Skopal

A method for constructing curves is proposed that are linear in a wide region and from whose slopes it is possible to determine the rate constant, if a parameter, θ, is calculated numerically from a rapidly converging recurrent formula or from its explicit form. The values of rate constants and parameter θ thus simply found are compared with those found by an optimization algorithm on a computer; the deviations do not exceed ±10%.


1999 ◽  
Vol 64 (4) ◽  
pp. 585-594 ◽  
Author(s):  
Barbara Marczewska

The acceleration effect of p-toluidine on the electroreduction of Zn(II) on the mercury electrode surface in binary mixtures water-methanol and water-dimethylformamide is discussed. The obtained apparent and true forward rate constants of Zn(II) reduction indicate that the rate constant of the first electron transfer increases in the presence of p-toluidine. The acceleration effect may probably be accounted for by the concept of the formation on the mercury electrode an activated complex, presumably composed of p-toluidine and solvent molecules.


1995 ◽  
Vol 73 (12) ◽  
pp. 2137-2142 ◽  
Author(s):  
A.J. Elliot ◽  
M.P. Chenier ◽  
D.C. Ouellette

In this publication we report: (i) the rate constants for reaction of the hydrated electron with 1-hexyn-3-ol ((8.6 ± 0.3) × 108 dm3 mol−1 s−1 at 18 °C), cinnamonitrile ((2.3 ± 0.2) × 1010 dm3 mol−1 s−1 at 20 °C), and 1,3-diethyl-2-thiourea ((3.5 ± 0.3) × 108 dm3 mol−1 s−1 at 22 °C). For cinnamonitrile and diethylthiourea, the temperature dependence up to 200 °C and 150 °C, respectively, is also reported; (ii) the rate constants for the reaction of the hydroxyl radical with 1-hexyn-3-ol ((5.5 ± 0.5) × 109 dm3 mol−1 s−1 at 20 °C), cinnamonitrile ((9.2 ± 0.3) × 109 dm3 mol−1 s−1 at 21 °C), and diethylthiourea ((8.0 ± 0.8) × 108 dm3 mol−1 s−1 at 22 °C). For cinnamonitrile, the temperature dependence up to 200 °C is also reported; (iii) the rate constant for the hydrogen atom reacting with 1-hexyn-3-ol ((4.3 ± 0.4) × 109 dm3 mol−1 s−1 at 20 °C). Keywords: radiolysis, corrosion inhibitors, rate constants.


2010 ◽  
Vol 171-172 ◽  
pp. 15-18
Author(s):  
Zeng Quan Ji ◽  
Tian Hai Wang ◽  
Kai Hong Luo ◽  
Yao Qing Wang

An extracellular biopolymer (PFC02) produced by Pseudomonas alcaligenes was used as an alternative biosorbent to remove toxic Cd(II) metallic ions from aqueous solutions. The effect of experimental parameters such as pH, Cd(II) initial concentration and contact time on the adsorption was studied. It was found that pH played a major role in the adsorption process, the optimum pH for the removal of Cd(II) was 6.0. The FTIR spectra showed carboxyl, hydroxyl and amino groups of the PFC02 were involved in chemical interaction with the Cd(II) ions. Equilibrium studies showed that Cd(II) adsorption data followed Langmuir model. The maximum adsorption capacity (qmax) for Cd(II) ions was estimated to be 93.55 mg/g. The kinetic studies showed that the kinetic rates were best fitted to the pseudo-second-order model. The study suggestted that the novel extracellular biopolymer biosorbent have potential applications for removing Cd(II) from wastewater.


1975 ◽  
Vol 105 (2) ◽  
pp. 317-321 ◽  
Author(s):  
J.N. Miller ◽  
O. Erinle ◽  
Janet M. Roberts ◽  
Christine Thirkettle

1991 ◽  
Vol 69 (2) ◽  
pp. 363-367
Author(s):  
Guoying Xu ◽  
Jan A. Herman

Ion/molecule reactions in mixtures of ethyl chloride with C1–C4 alkylamines were studied by ICR mass spectrometry. Ethyl cation transfer to C1–C4 alkylamines proceeds mainly through diethylchloronium ions with rate constants ~3 × 10−10cm3 s−1. In the case of s-butylamine the corresponding rate constant is 0.5 × 10−10 cm3 s−1. Key words: ICR mass spectrometry, ion/molecule reactions, ethylchloride, methylamine, ethylamine, propylamines, butylamines


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