Oligomeric enzymes

Oligomeric proteins consist of two or more polypeptide chains, which are usually linked to each other by non-covalent interactions and never by peptide bonds. The component polypeptide chains are termed sub-units and may be identical to or different from each other, if they are identical, they are sometimes called protomers.  Dimeric proteins consist of two, trimeric proteins of three and tetrameric proteins of four subunits. The molecular weight is usually in excess of 35000 Da. The vast majority of known enzymes are oligomeric, which include  lactate dehydrogenase, lactose synthase, tryptophan synthase and pyruvate dehydrogenase