Bonds drug-receptor

This equation shows that the most relevant computational information on the drug-receptor complex is encoded both in reactivity (hydrogen bond donor propensity) and in shape descriptors. 

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 ... 

Thus, non-covalent hydrophobic interactions, hydrogen bonds, and electrostatic bonds all contribute to the overall shape of a protein (Figure 13.3). As we shall see (Section 13.3.2), many pertinent properties of a protein are then provided by the appropriate combination of the remaining amino acid side-chains that reside on the surface, allowing specific binding to various molecules. This is the essence of enzymic activity and drug-receptor interactions. 

Noncovalent bond. There is no formation of a shared electron pair. The bond is reversible and typical of most drug-receptor interactions. Since a drug usually attaches to its site of action by multiple contacts, several of the types of bonds described below may participate. 

Kenakin TP. Pharmacological Analysis of Drug-receptor Interaction. New York Lippincott-Raven, 1993. Kenakin TP, Bond RA, and Bonner TI. Definition of pharmacological receptors. Pharmacol Rev 1992 44 351-362. 

P. A. Kolhnan (1980). The nature of the drug-receptor bond. In M. F. Wolff (Ed.). The Basis of Medicinal Chemistry, 4th ed. Part 1. New York Wiley-Interscience, pp. 313-329. 

SIGNIFICANCE OF CHEMICAL BONDING IN DRUG-RECEPTOR INTERACHONS... 

Significance of chemical bonding in drug-receptor 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. 

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