transmembraner

Transmembraner is a term used to describe an entity that spans a biological membrane, crossing from one side of the lipid bilayer to the other. In practice, the concept is most often expressed with the more common terms transmembrane protein or transmembrane segment. The word transmembraner is not widely standardized in the literature, but it serves as a descriptive label for anything that traverses membranes, including proteins, peptides, and, in some contexts, protein complexes.

Most transmembraner molecules contain hydrophobic regions that form the membrane-spanning portions. These segments are typically alpha helices or beta-barrels that accommodate the hydrophobic core of the lipid bilayer. Many transmembraner proteins are integral membrane proteins, anchored in the membrane by one or more transmembrane helices. They can function as channels or transporters, enzymes, receptors, or structural components that mediate signaling, substance exchange, or membrane organization.

Identification and study of transmembraners rely on sequence analysis and topology prediction, using hydrophobicity plots and computational tools such as TMHMM or Phobius. Experimental approaches include crystallography, cryo-electron microscopy, and biochemical methods that probe membrane integration and orientation. Distinguishing transmembraner proteins from peripheral membrane proteins, which associate with the membrane surface rather than spanning it, is a common area of investigation.

See also: transmembrane protein, membrane protein topology, hydrophobicity analysis, alpha-helix, beta-barrel. Notes: because “transmembraner” is less standard than “transmembrane protein,” authors typically prefer the latter term for clarity.