dissociation constant


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dissociation constant

[də‚sō·sē′ā·shən ‚kän·stənt]
(physical chemistry)
A constant whose numerical value depends on the equilibrium between the undissociated and dissociated forms of a molecule; a higher value indicates greater dissociation.
References in periodicals archive ?
Furthermore, the ANS quenching assay and quantitative TSA evaluated the selected compounds/extracts bound to hPPAR[beta]/[delta] LBD, providing dissociation constant values.
These plots reveal if the ligand has the ability to form a slowly dissociating step and what the on- and off-rate constants of the slowly dissociating step are, the dissociation constant of the fast step ([K.sub.A]), and the inhibition constant of the other ligand.
The following inhibitory complexes are allowed: EI, E[I.sub.2], ESI, and ES[I.sub.2]; [K.sub.i1], [K.sub.i2], [K.sub.i3], and [K.sub.i4] are the corresponding dissociation constants of these complexes (inhibitor constants).
For those complexes that are modified from relevant monomers, we will assume that the association and dissociation constants are the same as those for the monomer associations or dimer dissociations, respectively.
(1974) Ca-Maleic Acid 2.43 Martell and Smith (1974) Ca-itaconic Acid 1.20 Martell and Smith (1974) Fe-Maleic Acid 5.15 Martell and Smith (1974) Fe-itaconic Acid <5.15 Present study Al-Maleic Acid 5.47 Martell and Smith (1974) Al-Itaconic Acid <5.47 Present study AlP[O.sub.4] x 2[H.sub.2]O 22.1 Lindsay(1979) FeP[O.sub.4] x 2[H.sub.2]O 19.2 Lindsay (1979) U-Maleic Acid 5.15 Ramamoorthy and Santappa (1969) U-Itaconic Acid 4.86 Ramamoorthy and Santappa (1969) (A) 'K' refers to dissociation constant of cation-chelate or solubility-product constant of solid water-insoluble compound.
Another polyphenolic compound, the flavonolignan silibinin, has been previously showed to bind PDIA3 with a dissociation constant within micromolar range [47].
By such a simple experiment, the dissociation constant of the complex between the saccharide and ConA can be determined as an inhibition constant ([K.sub.I]) according to Eq.
The acid dissociation constants were determined by titrating 50.00 mL of ligands with standardized NaOH solution and three titrations were performed for each ligand.
ANS displacement studies have frequently been used to determine dissociation constants for potential ligands of TTR (Cao et al.
[22.] Lineweaver, H and Burk, D, "The determination of enzyme dissociation constants", Journal of the American Chemical Society 1934; 56: 658-666.
The values of apparent dissociation constants [pK.sub.m.sup.H] at [alpha]= 0.5 and the empirical n-value, given in table 3, in good agreement with those of the literature data [2-6].
Therefore, if [alpha] = 1, there is no difference between the enzyme-substrate dissociation constants on the first and on the second step.