21. Catalase is a tetramer of four polypeptide chains, each over 500 amino acids long. 22. This cytokeratin tetramer is considered to be the main building block of the cytokeratin chain. 23. Oats and barley differ in the ratio of trimer and tetramer 1-4 linkages. 24. This enzyme is a tetramer , meaning it has four subunits in its quaternary structure. 25. 3-Phosphoglycerate dehydrogenase is a tetramer , composed of four identical, asymmetric subunits. 26. It is a cyclic tetramer of ethylene oxide which is specific for the lithium cation. 27. Higher aggregates, such as a tetramer , ( AB ) 4 may be formed. 28. The anhydrous form exists as the tetramer [ Co ( acac ) 2 ] 4. 29. The TRPV6-ARD does not assemble as a tetramer and is monomeric in solution. 30. The lac repressor is a four-part protein, a tetramer , with identical subunits.
