association constant


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Related to association constant: dissociation constant

as·so·ci·a·tion con·stant

1. in experimental immunology, a mathematical expression of hapten-antibody interaction: average association constant, K = [hapten-bound antibody]/[free antibody][free hapten];
2. the equilibrium constant involved in the association of two or more compounds or ions into a new compound; the reciprocal of the dissociation constant.
Synonym(s): binding constant
References in periodicals archive ?
The standard free energy changes (IGAdeg) [22] associated with antihistamines complexes were calculated from the association constants by applying equation IGAdeg = -2.303 RT log Kc, where R is the gas constant (1.987 cal mol-1 deg-1), T is temperature in Kelvin and Kc is the association constant of drug-acceptor complexes.
The receptor also exhibits good interactions for [Cl.sup.-], HS[O.sub.4.sup.-], and [H.sub.2]P[O.sub.4.sup.-] with association constants of 3.1, 2.9 and 3.0 (in log K), respectively.
After interaction between BSA-carboxamide derivatives of amino acid, different association constant values at different pH obtained.
Generally, standard free energy changes become more negative as the association constants for molecular complex increase, because the bond between the components becomes stronger and thus the components are subjected to more physical strain or loss of freedom, so the values of AG[degrees] more negative.
(III) Association/dissociation of Cc-cC (association constant [k.sub.3]; dissociation constant [l.sub.3]):
The values of permeability P, initial flux [J.sub.0], (Table 2), association constant [K.sub.ass], and apparent diffusion coefficient [D.sup.*] (Table 3), relating to this facilitated extraction phenomenon of [VO.sub.2.sup.+] ions, clearly show that, for the same concentration of the extractive agent (0.01 M) and at the same temperature (293 K), the facilitated extraction of the substrate ([VO.sub.2.sup.+]) is more efficient through SLM containing trioctylamine (TOA) as extractive agent, compared with two other investigated membranes, containing, respectively, methyl cholate (MC) and resorcinarene (RESO).
Association constants were obtained by analyzing the individual titration experiments as described above, and the values obtained at different temperatures are given in Fig.
In order to explain the nature of the interaction between isoimperatorin and HSA, the association constant of HSA-isoimperatorin complex was determined at four different temperatures (298, 303, 308, and 313 K).
We hypothesized that 5-diol, whose association constant for SHBG (1.5 x [10.sup.9] L/mol) (7) is practically the same as that of testosterone for SHBG (1.6 x [10.sup.9] L/mol) (7), could modulate SHBG testosterone binding in men.
where [[P.sub.1]] is the concentration of propagator monomers, [[P.sub.k]] is the concentration of propagator aggregates consisting of k monomers, [T] is the concentration of terminators, K is the association constant, and i is a "diminution" parameter that has a value between zero and unity.
Table 3: Association rate constants for ferrocene-alkyl chloride CTCs Acceptor Donor Association constant at 310 nm (L/mol) Ferrocene Dichloromethane 39.25 Benzyl chloride 1.04 Methoxyferrocene Dichloromethane 15.73 Benzyl chloride 0.0724 Cyanoferrocene Dichloromethane 26.08 Benzyl chloride 9.87
For the Scatchard analysis, binding affinity of BSA and 4-HP2OTP and 2-HP2STP is expressed as an association constant or binding constant which is derived from the law of mass action.

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