Artificial allosteric receptors.

Cooperative effects in the binding of two or more substrates to different binding sites of a receptor that are a result of a conformational change caused by the binding of the first substrate--also referred to as the effector--are called allosteric effects. In biological systems, allosteric regulation is a widely used mechanism to control the function of proteins and enzymes in cellular metabolism. Inspired by this a lot of efforts have been made in supramolecular chemistry to implement this concept into artificial systems to control functions as molecular recognition, signal amplification, or even reactivity and catalysis. This review gives an up-to-date overview over the different approaches that have been reported ever since the first examples from the late 1970s/early 1980s. It covers both homo- and heterotropic examples and is divided according to the nature of the effector--cationic, anionic, or neutral--effectors and systems that use combinations of those.