Table 1.

Examples of iron-containing proteins with the type of the iron complex prosthetic group and protein function.

Protein	Iron Complex Prosthetic Group	Function
Hemoglobin	Heme	Oxygen transport
Myoglobin	Heme	Oxygen transport
Cytochromes	Heme	Electron transport. Respiration
Cytochrome P450	Heme	Drug detoxification
Ribonucleotide reductase	Amino acids	DNA synthesis
Proline hydroxylase	Amino acids	Collagen synthesis
Phenylalanine hydroxylase	Amino acids	Degradation of phenylalanine
Tryptophan 2,3-dioxygenage	Heme	Degradation of tryptophan
Homogentisic acid 2,3-dioxygenase	Amino acids	Detection of alkaptonuria
Peroxidases	Heme	Decomposition of hydroperoxides
Catalase	Heme	Decomposition of hydrogen peroxide
Lipoxygenase	Amino acids	HPETE and leukotriene synthesis
Cyclooxygenase	Heme and Amino acids	Prostaglandin and thromboxane synthesis
Adrenodoxin	2Fe-2S	Electron transport. Oxidation/reduction
Aconitase	4Fe–4S	Tricarboxylic acid cycle
Succinate dehydrogenase	2Fe-2S, 4Fe–4S, 3Fe-4S	Tricarboxylic acid cycle
NADH dehydrogenase	Fe–S Clusters	Electron transport. Respiration
Xanthine oxidase	4x (2Fe-2S)	Conversion of xanthine to uric acid
Aldehyde oxidase	2x (2Fe-2S)	Metabolism of aldehydes
Transferrin	Amino Acids	Iron transport in plasma
Lactoferrin	Amino Acids	Iron binding in milk and secretions
Ferritin	Oxyhydroxide, phosphate Fe	Iron storage
Hemosiderin	Oxyhydroxide, phosphate Fe	Iron storage
Hephaestin	Not carrying or containing Fe	Ferroxidase and influx transmembrane iron transport
Ferroportin	Not carrying or containing Fe	Efflux transmembrane iron transporter in cells
Hepcidin	Not carrying or containing Fe	Regulatory protein affecting iron uptake and release