Abstract
Molecular recognition between molecules is one of the most fundamental processes in biology and chemistry. The recognition process is largely driven by non-covalent forces such as hydrogen bonding, electrostatics, van der Waals forces, π-π interactions, and conformational energy. The complementarity between the receptor and substrate is very similar to the “lock and key” function, first described by Emil Fischer over 100 years ago, - the lock being the molecular receptor such as a protein or enzyme and the key being the substrate such as a drug, that is recognized to give a defined receptor-substrate complex. This review focuses on the design of specific ligand systems as “Keys” to enable the induced fit of these keys into the target macromolecules, protein/enzyme (Locks) with particular emphasis on protein recognition.