Coenzymes: Haem


The tetrapyrrole porphyrin haem prosthetic group is found in a wide variety of proteins in almost all prokaryotic organisms. These proteins perform a diverse range of functions, including dioxygen binding, oxygen atom transfer, substrate oxidation and electron transport.

Keywords: haem; porphyrin; peroxidase; oxygenase

Figure 1.

Naturally occurring haems.

Figure 2.

Haem structures.

Figure 3.

Chlorophyll a.

Figure 4.

Oxygen complex structures.

Figure 5.

Horseradish peroxidase cycle.

Figure 6.

Formation of peroxidase compound I.

Figure 8.

The ‘push–pull‘ mechanisms for dioxygen bond cleavage in cytochrome P450 and peroxidase systems.



Dawson JH (1988) Probing structure–function relations in heme‐containing oxygenases and peroxidases. Science 240: 433–439.

Dawson JH and Sono M (1987) Cytochrome P450 and chloroperoxidase: thiolate‐ligated heme enzymes. Spectroscopic determination of their active site structures and mechanistic implications of thiolate ligation. Chemical Reviews 87: 1255–1276.

Dunford HB and Stillman JS (1976) On the function and mechanism of action of peroxidases. Coordination Chemical Review 19: 187–251.

English AM and Tsaprailis G (1995) Catalytic structure–function relationships in heme peroxidases. Advances in Inorganic Chemistry 43: 79–125.

Sono M, Roach MP, Coulter ED and Dawson JH (1996) Heme‐containing oxygenases. Chemical Reviews 96: 2841–2888.

Further Reading

Lippard SJ and Berg JM (1994) Principles of Bioinorganic Chemistry. Mill Valley, CA: University Science Books.

Branden C and Toose J (1991) Introduction to Protein Structure. New York: Garland Publishing.

Dunford HB (1991) Horseradish peroxidase: structure and kinetic properties. In: Everse J, Everse KE and Grisham MB (eds) Peroxidases in Chemistry and Biology, pp. 1–24. Boca Raton, FL: CRC Press.

English AM (1994) Iron: heme proteins, peroxidases, and catalases. In: King RB (ed.) Encyclopedia of Inorganic Chemistry, pp. 1682–1697. New York: Wiley.

Ingraham LL and Meyer DL (1985) Biochemistry of Dioxygen. New York: Plenum Press.

Kadish KM, Smith KM and Guilard R (eds) (2000) The Porphyrin Handbook. New York: Academic Press.

Sono M and Dawson JH (1994) Iron: heme proteins, mono‐ and dioxygenases. In: King RB (ed.) Encyclopedia of Inorganic Chemistry, pp. 1661–1682. New York: Wiley.

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How to Cite close
Cheek, Jennifer, and Dawson, John H(Apr 2001) Coenzymes: Haem. In: eLS. John Wiley & Sons Ltd, Chichester. [doi: 10.1038/npg.els.0000667]