Drug Targets

This chapter discusses major drug targets including enzymes, receptors, ion channels, carrier proteins, structural proteins, nucleic acids, and protein-protein interactions and provides a brief discussion on the selection and validation of drug targets. Target selection is influenced by a balance of complex scientific, medical, and strategic considerations. In selecting a drug target, the reliability of its genesis decreases as the following: pharmacology in human disease; pharmacology in animal model; animal model availability; cell model; literature precedent; anecdotal findings; and hunch. Once a target is identified, target validation is the next essential step. Drug target validation is to ascertain that the drugs are hitting the intended targets rather than offtargets. Like catalysts in chemical reactions, enzymes are catalysts in the body. The chapter examines the six major classes of enzymes: oxidoreductases, transferase, hydrolase, lyase, isomerase, and ligase.