The Concept of Receptor and Molecule Interaction in Drug Discovery and Development

Abstract

The mechanisms by which drugs act are different and unique to each class as they involve interactions with pharmacological receptors, enzymes, ion channels, and cellular transport processes. Hormones, neurotransmitters, and autocoids are natural chemical messengers that have a role in physiological and pathological regulatory processes. The interpretation of their action is determined by the localization and functional capacity of the specific receptor with which the �first messenger� interacts and the concentration of the chemical to which the receptor is exposed. This chapter focuses on physiological receptors where many of the drugs act in a manner similar to endogenous agonists or interfere with their interaction at the target to alleviate the symptoms of a disease. While doing so, many of these molecules have shown selectivity for receptor subtypes and signaling pathways. This is based on pharmacological scales such as affinity and intrinsic efficacy, and methods to quantify them are described within a theoretical concept. Based on these two drug properties, the overt action of a drug may be agonism or antagonism. Added to this gallery are allosteric modulators (positive or negative), partial agonists, inverse agonists, and biased agonists and antagonists. These are discussed with examples. Such new drug development is believed to improve the treatment of diseases with fewer adverse effects as a drug�s therapeutic and adverse effects are mediated by distinct pathways. In this chapter, we have extended the classical concept of the initiation of a pharmacological response with the binding of a drug to a receptor to the complexity of selectivity for receptor subtypes and signaling pathways. � Springer Nature Singapore Pte Ltd. 2021.