Coenzymes and Cofactors

Joan B Broderick, Michigan State University, East Lansing, Michigan, USA

Published online: April 2001

DOI: 10.1038/npg.els.0000631

Coenzymes and cofactors are molecules or ions that are used by enzymes to help catalyse reactions. Coenzymes are typically organic molecules that contain functionalities not found in proteins, while cofactors are catalytically essential molecules or ions that are covalently bound to the enzyme.

Keywords: enzyme; catalysis; functional group; metallocofactors

Figure 1. Mechanism of the serine proteases. Note the role of general acid–base catalysis in each step of the mechanism. Step 1, nucleophilic attack of the serine hydroxyl on the substrate. Step 2, collapse of tetrahedral intermediate to the acyl enzyme intermediate. Step 3, release of amine product. Step 4, deacylation resulting from nucleophilic attack of water to form a tetrahedral intermediate. Step 5, collapse of the tetrahedral intermediate and release of carboxyl product.
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 Further Reading
    book Bertini I, Gray HB, Lippard SJ and Valentine JS (1994) Bioinorganic Chemistry. Sausalito, CA: University Science Books.
    book Fersht A (1999) Structure and Mechanism in Protein Science. New York: W.H. Freeman & Co.
    Ludwig ML and Matthews RG (1997) Structure-based perspectives on B12-dependent enzymes. Annual Review of Biochemistry 66: 269–313.
    book Reedijk J (1993) Bioinorganic Catalysis. New York: Marcel Dekker.
    book Sigel H and Sigel A (1994) Metalloenzymes Involving Amino Acid-Residue and Related Radicals. New York: Marcel Dekker.
    book Walsh CT (1979) Enzymatic Reaction Mechanisms. San Fransisco: W.H. Freeman & Co.

Related Sub-Topics:

Other Biomolecules: Structure, Function, Metabolism | Enzymes: Structure and Action Mechanism
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Article Title: Coenzymes and Cofactors
 
How to Cite close
Broderick, Joan B(Apr 2001) Coenzymes and Cofactors. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1038/npg.els.0000631]