dimer A protein that is made up of two polypeptide chains or subunits paired together. If the subunits are identical in aminoacid sequence the protein is said to be homomeric; if they are different, it is heteromeric. Dimeric proteins may be detected by electrophoresis. In monomeric enzymes, the isoenzyme pattern of the heterozygote will represent a simple mixture of the two forms occurring by themselves in each of the corresponding homozygotes. In dimeric enzymes, there are homomeric forms representing the two homozygotes, but the heterozygote occurs in heteromeric form: when stained after electrophoresis, this results in three bands (instead of two bands as with a monomer). An example of a dimeric enzyme is glucose–phosphate isomerase. Some enzymes are trimeric (comprising three components) or tetrameric (with four components).

dimer A protein that is made up of two polypeptide chains or subunits paired together. If the subunits are identical in amino-acid sequence the protein is said to be homomeric; if they are different, it is heteromeric. Dimeric proteins may be detected by electrophoresis. In monomeric enzymes, the isozyme pattern of the heterozygote will represent a simple mixture of the two forms occurring by themselves in each of the corresponding homozygotes. In dimeric enzymes, there are homomeric forms representing the two homozygotes, but the heterozygote occurs in heteromeric form: when stained after electrophoresis, this results in 3 bands (instead of 2 bands as with a monomer). An example of a dimeric enzyme is glucose-phosphate isomerase. Some enzymes are trimeric (comprising 3 components) or tetrameric (with 4 components).

di·mer / ˈdīmər/ • n. Chem. a molecule or molecular complex consisting of two identical molecules linked together.DERIVATIVES: di·mer·ic / dīˈmerik/ adj.