DRUG RECEPTORS
Introduction
At the heart of pharmacology lies the intricate dance between drugs and their biological targets.
These targets, predominantly proteins embedded within cell membranes or residing within the
cellular cytoplasm, are known as drug receptors. Understanding the nature of drug receptors,
their diverse structures, and their interactions with drug molecules is fundamental to
comprehending the mechanisms of drug action and the development of novel therapeutic
strategies.
What Are Drug Receptors?
Drug receptors are specialized protein molecules that serve as the initial point of interaction for
drug molecules within the body. These receptors possess specific binding sites, often referred to
as ligand-binding domains, that exhibit a high degree of affinity and selectivity for particular
drug molecules. The binding of a drug to its receptor initiates a cascade of biochemical events
that ultimately lead to a physiological or pharmacological response.
Types of Drug Receptors
Drug receptors are broadly classified into four major superfamilies, each characterized by
distinct structural features and signaling mechanisms:
1. G protein-coupled receptors (GPCRs): This is the largest and most diverse family of drug
receptors, encompassing a wide range of physiological processes, including
neurotransmission, hormone signaling, and sensory perception. GPCRs are characterized
by their seven transmembrane domains, which span the cell membrane and couple to
intracellular G proteins. Upon drug binding, GPCRs activate G proteins, which in turn
modulate the activity of downstream effector enzymes or ion channels.
2. Ion channel-linked receptors: These receptors are integral membrane proteins that form
ion-conducting pores across cell membranes. Drug binding to these receptors can either
open or close the ion channel, resulting in changes in ion permeability and membrane
Introduction
At the heart of pharmacology lies the intricate dance between drugs and their biological targets.
These targets, predominantly proteins embedded within cell membranes or residing within the
cellular cytoplasm, are known as drug receptors. Understanding the nature of drug receptors,
their diverse structures, and their interactions with drug molecules is fundamental to
comprehending the mechanisms of drug action and the development of novel therapeutic
strategies.
What Are Drug Receptors?
Drug receptors are specialized protein molecules that serve as the initial point of interaction for
drug molecules within the body. These receptors possess specific binding sites, often referred to
as ligand-binding domains, that exhibit a high degree of affinity and selectivity for particular
drug molecules. The binding of a drug to its receptor initiates a cascade of biochemical events
that ultimately lead to a physiological or pharmacological response.
Types of Drug Receptors
Drug receptors are broadly classified into four major superfamilies, each characterized by
distinct structural features and signaling mechanisms:
1. G protein-coupled receptors (GPCRs): This is the largest and most diverse family of drug
receptors, encompassing a wide range of physiological processes, including
neurotransmission, hormone signaling, and sensory perception. GPCRs are characterized
by their seven transmembrane domains, which span the cell membrane and couple to
intracellular G proteins. Upon drug binding, GPCRs activate G proteins, which in turn
modulate the activity of downstream effector enzymes or ion channels.
2. Ion channel-linked receptors: These receptors are integral membrane proteins that form
ion-conducting pores across cell membranes. Drug binding to these receptors can either
open or close the ion channel, resulting in changes in ion permeability and membrane
