Drug-receptor interactions, forces

Electrostatic forces are due to the ionic charges residing on the molecules, which attract or repel each other. The macromolecular structures of the receptors and enzymes mean that there are a number of ionic charges to attract the oppositely charged drug molecules. The forces of electrostatic interactions are weaker than covalent bonding. Electrostatic interactions are more common in drug-receptor interactions. There are two types of electrostatic interactions ... 

Formation of hydrophobic bonds between nonpolar hydrocarbon groups on the drug and those in the receptor site is also common. Although these bonds are not very specific, the interactions take place to exclude water molecules. Repulsive forces that decrease the stability of the drug-receptor interaction include repulsion of like charges and steric hindrance. 

Electrostatic bonding is much more common than covalent bonding in drug-receptor interactions. Electrostatic bonds vary from relatively strong linkages between permanently charged ionic molecules to weaker hydrogen bonds and very weak induced dipole interactions such as van der Waals forces and similar phenomena. Electrostatic bonds are weaker than covalent bonds. 

As for van der Waals forces, hydrophobic interactions are individually weak (0.1 to 0.2 kJ moF for every square angstrom of solvent-accessible hydrocarbon surface ), but the total contribution of hydrophobic bonds to drug-receptor interactions is substantial. Similarly, the overall strength of the hydrophobic interaction between two molecules is very dependent on the quality of the steric match between the two molecules. If this is not sufficiently close to squeeze all of the solvent from the interface, a substantial entropy penalty must be paid for each of the trapped water molecules. 

Parameters which encode certain structural features and properties are needed to correlate biological activities with chemical structures in a quantitative manner. Of special value are physicochemical properties which are directly related to the intermolecular forces involved in the drug-receptor interaction as well as to the transport and distribution properties of drugs. In this respect hydrophobic, polar, electronic, and steric properties are most important most often, polarizability parameters are considered as being closely related to steric parameters and are discussed together with these parameters, although they are definitely different (if structural variation is appropriate). 

Forces that Influence the Drug-Receptor Interactions. 85... 

There are three major types of chemical forces/bonds that are involved in drug-receptor interactions. 

Medicinal chemists and pharmacologists being forced to study drug-induced phenomena so poorly defined that they may be described as "happenings in a garbage can" are limited in the questions about drug-receptor interactions to which they can expect detailed answers at this time. 

Kier" " had shown that part of the drug-receptor interaction is due to long-range forces of dispersion and polarization, It is known that the polarizability of atoms in a molecule gives rise on one... 

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