Heteromer

Part of speech: noun

Definitions

1. A complex formed from two or more different kinds of subunits joined together, such as a protein assembled from distinct polypeptide chains
2. A molecular assembly built from unlike components, particularly a protein made up of several differing subunits bound into one structure
3. Any compound whose building blocks are not all identical, especially a multi-subunit protein composed of varied chains linked together

Etymology: Built from Greek "heteros", meaning "other" or "different", and "meros", meaning "part", this term describes something made of differently constituted parts. It is a modern technical coinage from classical roots, not a word that circulated in antiquity. In biochemistry, a heteromer is a protein complex assembled from two or more different subunits. Its counterpart, a homomer, is built from identical copies of one subunit. The pairing works because "homo-" means "same", so the two terms divide protein assemblies into a simple contrast. Many ion channels and receptors are heteromers, and the distinction can matter for how a drug binds to them.