Binding constant

The measurement of binding constants (also called stability constants or formation constants) is of interest in many areas of chemistry. Quantitative information concerning the products of acid-base, metal-ligand or enzyme-substrate interactions is invaluable in analytical chemistry, industrial process chemistry, biochemistry, etc. 

The binding constants (illustrated here as metal-ligand formation constants) may be either stepwise formation constants (equation 22-1) or cumulative formation constants Pn (equation 22-2). Charges have been omitted for clarity. 

The relationship between stepwise and cumulative formation constants is 

Writing the equilibrium constant as a cumulative equilibrium constant does not indicate that two or more ligands are added simultaneously. All association reactions occur in a stepwise manner, although in a few cases the successive reactions overlap extensively. 

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Bdhm H-J 1994 The development of a simple empirical scoring function to estimate the binding constant for a protein-ligand complex of known three-dimensional structure J. Comp.-Aided Mol. Design 8 243-56... 

However, the B.E.T. and modificated B.E.T as well as isotherm of d Arcy and Watt fit the experimental data only in some range of the relative humidities up to about 80-85%. At the same time the adsorption in the interval 90-100% is of great interest for in this interval the A— B conformational transition, which is of biological importance, takes place [17], [18]. This disagreement can be the result of the fact that the adsorbed water molecules can form a regular lattice, structure of which depends on the conformation of the NA. To take into account this fact we assume that the water binding constants depend on the conformational variables of the model, i.e ... 

Absolute Binding Constants from First Principles ... 

Jedrzejas, M. J., Singh, S. Brouillette, W. J. Air, G. M. Luo, M. A. 1995. Strategy for theoretical binding constant, Ki calculation for neuraminidase aromatic inhibitors, designed on the basis of the active site structure of influenza virus neuraminidase. Proteins Struct. Funct. Genet. 23 (1995) 264-277... 

H-J 1998. Prediction of Binding Constants of Protein Ligands A Fast Method for the aritisation of Hits Obtained from De Novo Design or 3D Database Search Programs. Journal of nputer-Aided Molecular Design 12 309-323. 

One example has already been encountered in the form of the binding constants in Table 3.2. These data form one of the first examples of compelling evidence for the involvement of attractive arene -arene interactions in determining the outcome of enantioselective catalysis. These attractive interactions have been frequently invoked as explanations for the observed enantioselectivities of... 

Despite the availability of relevant mechanistic parameters in the form of the rate constants and binding constants in Table 3.2, rationalisation of the observed enantioselectivities is still rather complicated and therefore some additional information has been gathered. 

Orstan, A. Wojcik, J. F. Spectroscopic Determination of Protein-Ligand Binding Constants, /. Chem. Educ. 1987, 64, 814-816. 

The nature of the hormone—NP link is unclear. Although the binding is quite specific, it is sufficientiy weak, ie, binding constant 10 10 M (71), as to cast doubt upon a protective role. However, no compelling evidence for a biological function for the neurophysins, other than as hormone carriers, has been elucidated (59,72). 

The low detection limit, high sensitivity, and fast response times of chemoreceptor-based biosensors result primarily from the extremely high binding constants of the receptor R for the target substrate S. The receptor—substrate binding may be described... 

The binding constant is defined by the equiHbrium constant for the reaction... 

Receptor—substrate-binding constants are typically between 10 and 10, at equimolar ratios, implying that when a receptor—substrate... 

It was established that Ab to Klebsiella pneumoniae didn t demonstrate the cross-reactivity to antigens of the relative bacterial species so, it could be considered that antibodies investigated was highly specific only to the own antigen. The physical-chemical characteristics of the immunological interaction such as constants of formation of Ag-Ab complex were obtained. The binding constants of immune complex were Ka =(9.7 l.l)-10 and Ka,=(1.7+0.3)T0 (mg/ml)f... 

The mechanism of interaction with DNA is suggested. Ethidium bromide (EB) displacement assay was performed. We determine the binding constant of Tb-E to DNA to be in the order of Ig K = 6.47 0.4. The bathochromic and hypsochromic effects in the absorption spectra of investigated complex were observed and the interaction is assumed to be mainly of the mono-intercalating type. 

Distribution of benzodiazepines in system micellar pseudophase - water was investigated in micellar solutions of sodium dodecylsulfate. The protonization constants of benzodiazepines were determined by the UV-spectophotometry. Values of protonization constants increase with increasing of sodium dodecylsulfate concentration. The binding constants of two protolytic forms of benzodiazepines with a micellar pseudo-phase and P, values were evaluated from obtained dependence. 

To calculate the relative binding constants of the two ligands, Ligandl and Ligand2, we construct the following cyclic scheme. 

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