Ternary complex

A Ternary complex refers to a protein complex containing three different molecules which are bound together. In structural biology ternary complex can be used to describe a crystal containing a protein with two small molecules bound, for example cofactor and substrate; or a complex formed between two proteins and a single substrate. In Immunology, a ternary complex can refer to the MHC-Peptide-T-cell-receptor complex formed when T cells recognize epitopes of an antigen.

A ternary complex can also refer to a polymer formed by electrostatic interactions.