Molecular binding

Molecular binding is an attractive interaction between two molecules which results in a stable association in which the molecules are in close proximity to each other. The result of molecular binding is formation of a molecular complex.

Types

Molecular binding can be classified into the following types:^[1]

• non-covalent – no chemical bonds are formed between the two interacting molecules hence the association is fully reversible
• reversible covalent – a chemical bond is formed, however the free energy difference separating the non-bonded reactants from bonded product is near equilibrium and the activation barrier is relatively low such that the reverse reaction which cleaves the chemical bond easily occurs
• irreversible covalent – a chemical bond is formed in which the product is thermodynamically much more stable than the reactants such that the reverse reaction does not take place.

Examples

Molecules that can participate in molecular binding include proteins, nucleic acids, carbohydrates, lipids, and small organic molecules such as drugs. Hence the types of complexes that form as a result of molecular binding include:

• protein – protein^[2]
• protein – DNA^[3]
• protein – hormone
• protein – drug^[4]

Proteins that form stable complexes with other molecules are often referred to as receptors while their binding partners are called ligands.^[5]

See also

• Receptor (biochemistry)
• Supramolecular chemistry

References

1. ^ Smith AJ, Zhang X, Leach AG, Houk KN (January 2009). "Beyond picomolar affinities: quantitative aspects of noncovalent and covalent binding of drugs to proteins". J. Med. Chem. 52 (2): 225–33. doi:10.1021/jm800498e. PMC 2646787. PMID 19053779. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2646787. 
2. ^ Haian Fu (2004). Protein-protein interactions: methods and applications. Totowa, NJ: Humana Press. ISBN 1-58829-120-0. 
3. ^ Harald Seitz (2007). Analytics of Protein-DNA Interactions (Advances in Biochemical Engineering / Biotechnology). Berlin: Springer. ISBN 3-540-48147-8. 
4. ^ Gerd Folkers; Hans-Joachim Böhm; Gisbert Schneider; Raimund Mannhold; Hugo Kubinyi (2003). Protein-ligand interactions from molecular recognition to drug design. Weinheim: Wiley-VCH. ISBN 3-527-30521-1. 
5. ^ Klotz, Irving M. (1997). Ligand-receptor energetics: a guide for the perplexed. Chichester: John Wiley & Sons. ISBN 0-471-17626-5.