TY - JOUR
T1 - Quantification of the effects of ionic strength, viscosity, and hydrophobicity on protein-ligand binding affinity
AU - Papaneophytou, Christos P.
AU - Grigoroudis, Asterios I.
AU - McInnes, Campbell
AU - Kontopidis, George
PY - 2014/8/14
Y1 - 2014/8/14
N2 - In order to quantify the interactions between molecules of biological interest, the determination of the dissociation constant (Kd) is essential. Estimation of the binding affinity in this way is routinely performed in "favorable" conditions for macromolecules. Crucial data for ligand-protein binding elucidation is mainly derived from techniques (e.g., macromolecular crystallography) that require the addition of high concentration of salts and/or other additives. In this study we have evaluated the effect of temperature, ionic strength, viscosity, and hydrophobicity on the Kd of three previously characterized protein-ligand systems, based on variation in their binding sites, in order to provide insight into how these often overlooked unconventional circumstances impact binding affinity. Our conclusions are as follows: (1) increasing solvent viscosity in general is detrimental to ligand binding, (2) moderate increases in temperature have marginal effects on the dissociation constant, and (3) the degree of hydrophobicity of the ligand and the binding site determines the extent of the influence of cosolvents and salt concentration on ligand binding affinity.
AB - In order to quantify the interactions between molecules of biological interest, the determination of the dissociation constant (Kd) is essential. Estimation of the binding affinity in this way is routinely performed in "favorable" conditions for macromolecules. Crucial data for ligand-protein binding elucidation is mainly derived from techniques (e.g., macromolecular crystallography) that require the addition of high concentration of salts and/or other additives. In this study we have evaluated the effect of temperature, ionic strength, viscosity, and hydrophobicity on the Kd of three previously characterized protein-ligand systems, based on variation in their binding sites, in order to provide insight into how these often overlooked unconventional circumstances impact binding affinity. Our conclusions are as follows: (1) increasing solvent viscosity in general is detrimental to ligand binding, (2) moderate increases in temperature have marginal effects on the dissociation constant, and (3) the degree of hydrophobicity of the ligand and the binding site determines the extent of the influence of cosolvents and salt concentration on ligand binding affinity.
KW - Affinity
KW - dissociation constant
KW - fluorescence spectroscopy
KW - ion strength
KW - solvent
KW - viscosity
UR - http://www.scopus.com/inward/record.url?scp=84906270193&partnerID=8YFLogxK
U2 - 10.1021/ml500204e
DO - 10.1021/ml500204e
M3 - Article
AN - SCOPUS:84906270193
SN - 1948-5875
VL - 5
SP - 931
EP - 936
JO - ACS Medicinal Chemistry Letters
JF - ACS Medicinal Chemistry Letters
IS - 8
ER -