from Wikipedia, the free encyclopedia

An oligomer (from ancient Greek ὀλίγοι oligoi 'few' and μέρος méros 'part') is a molecule that is made up of several structurally identical or similar units. If there is a larger number of units, one speaks of a polymer . The distinguishing criterion according to IUPAC is whether a small change in the number of units causes a significant change in properties. The process of forming oligomers is known as oligomerization .

A single unit is called a monomer . According to the number of units, oligomers are usually named based on ancient Greek numerals : if they consist of two, three, four, five, six, seven, eight ... units they are called dimer , trimer , tetramer , pentamer, hexamer, heptamer, octamer.

If all subunits are identical to one another, one speaks of a homomeric oligomer or homomer , in the case of different subunits of a heteromer .

Oligomers occur, among other things, in the course of the polymerization (see e.g. urea resin ) or vice versa when polymers are broken down (see e.g. digestive enzyme ).

Use of language in biochemistry

The units of an oligomer are linked to one another. In the case of an oligopeptide, for example, this is a covalent bond, the peptide bond . However, amino acid chains of an oligopeptide or polypeptide formed in this way can fold into a protein and, in turn, assemble with other proteins to form a larger complex, to associate to form a protein complex . However, its subunits are usually not covalently linked to one another.

In biochemistry, an “oligomeric protein ” is not understood to be a protein made up of just a few amino acid units, that would be an oligopeptide, but a protein complex made up of several - equal or unequal - subunits. For example, a collagen fiber is a homomeric trimer , whereas hemoglobin is a heteromeric tetramer or heterotetramer .

See also

  • -mer : Notes on the -mer suffix

Web links

Wiktionary: Oligomer  - explanations of meanings, word origins, synonyms, translations

Individual evidence

  1. ^ JE Straub, D. Thirumalai: Principles governing oligomer formation in amyloidogenic peptides. In: Current opinion in structural biology. Volume 20, number 2, April 2010, pp. 187-195, doi : 10.1016 / j.sbi.2009.12.017 . PMID 20106655 . PMC 2854190 (free full text).