Atetramer (/ˈtɛtrəmər/) (tetra-, "four" + -mer, "parts") is an oligomer formed from four monomersorsubunits. The associated property is called tetramery. An example from inorganic chemistryistitanium methoxide with the empirical formula Ti(OCH3)4, which is tetrameric in solid state and has the molecular formulaTi4(OCH3)16.[1] An example from organic chemistryiskobophenol A, a substance that is formed by combining four molecules of resveratrol.[2][3]
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 biotininavidin tetramers, or have a common biological property, such as the allosteric bindingofoxygen in hemoglobin.