Homomerické

Homomerické is a term used in biochemistry and molecular biology to describe a macromolecular complex that is composed exclusively of identical subunits. The word combines homo- meaning same, with mer- meaning part, and is used to distinguish such assemblies from heteromerické, in which two or more different subunits are present.

In biology, homomeric assemblies are common in multimeric protein complexes, including ion channels, receptors, and structural or enzymatic proteins. Examples include homopentameric nicotinic acetylcholine receptors formed by identical α7 subunits, and certain bacterial ligand-gated channels such as GLIC that assemble from identical subunits. Connexin channels can form hexameric hemichannels that may be homomeric, and some voltage-gated channels assemble as homomeric tetramers of identical subunits. Heteromeric assemblies, by contrast, contain mixed subunits and often exhibit different properties or regulatory mechanisms.

Functional implications of homomericity include uniform binding interfaces and coordinated subunit interactions, which can influence ligand affinity, gating, conductance, and regulation. The simplicity of identical subunits can also affect evolutionary constraints and the range of functional states the complex can attain. Studying homomeric complexes typically involves expressing a single subunit type, followed by structural methods such as cryo-electron microscopy or X-ray crystallography, and functional assays like electrophysiology to characterize properties.

See also: heteromeric, oligomer, subunit, receptor, ion channel. In Czech literature, homomerické is used similarly to describe protein complexes composed of identical subunits, across various protein families and functional classes.