This invention is a new strategy using a rational design for a flexible drug carrier composition, meaning that it provides drug release with a conformational change under specific conditions. Said carrier in its closed conformation, contains a drug wherein significant release of Said drug from its carrier only occurs during or after said conformational change, such as when a ligand binding domain is removed. Said carrier can then undergo a molecular, conformational change to an open form. The term Allosteric Releasem is inspired by this inventive concept.