What is "tetramer"

oligomer \o*lig"o*mer\, n. (Chem.) A molecule composed of a small number of linked monomer units; a short polymer; -- compounds called oligomers have less than one hundred monomer units and usually less than thirty. Oligomers of increasing length are called dimer, trimer, tetramer, pentamer, hexamer, heptamer, octamer, nonamer, decamer, etc. In colloquial laboratory jargon, they may also be referred to as nine-mer, ten-mer, eleven-mer, twelve-mer, etc., especially for oligomers of greater than eight units.

n. (context chemistry English) An oligomer having four subunits

A tetramer (tetra-, "four" + -mer, "parts") is an oligomer formed from four monomers or subunits. The associated propriety is called tetramery. An example is kobophenol A, a molecule formed from four stilbenoids monomers.

In biochemistry, it similarly refers to a biomolecule formed of four units, that are the same ( homotetramer), i.e. as in Concanavalin A or different ( heterotetramer), i.e. as in hemoglobin. Hemoglobin has 4 similar sub-units while immunoglobulins have 2 very different sub-units. The different sub-units may have each their own activity, such as binding biotin in avidin tetramers, or have a common biological property, such as the allosteric binding of oxygen in hemoglobin.