Lewis acid

A Lewis acid is a chemical species defined by its ability to accept an electron pair from a Lewis base to form a Lewis adduct. In biological systems, this property is most commonly exemplified by metal cations, such as Zinc (Zn2+), Magnesium (Mg2+), and Iron (Fe2+/Fe3+), which function as essential cofactors within the active sites of numerous enzymes to facilitate catalysis and stabilize molecular structures. While Lewis acidity is a fundamental chemical principle that governs how many drugs interact with their biological targets—such as ACE inhibitors binding to the zinc ion in Angiotensin-Converting Enzyme—the term 'Lewis acid' itself does as not refer to a specific therapeutic target, protein, or gene. Consequently, it is classified as a general chemical category rather than a discrete molecule for drug development purposes.

Other names

Electron pair acceptorLewis acidic species

Lewis acids function by accepting an electron pair from a donor (Lewis base) to form a coordinate covalent bond. In pharmacology, this most often occurs when a drug molecule (acting as a Lewis base) binds to a metal ion cofactor (acting as a Lewis acid) within the active site of an enzyme.