biochemistry Biochemistry or biological chemistry is the study of chemical processes within and relating to living organisms. A sub-discipline of both chemistry and biology, biochemistry may be divided into three fields: structural biology, enzymology and ...

, non-heme iron proteins describe families of enzymes that utilize iron at the active site but lack

heme Heme, or haem (pronounced / hi:m/ ), is a precursor to hemoglobin, which is necessary to bind oxygen in the bloodstream. Heme is biosynthesized in both the bone marrow and the liver. In biochemical terms, heme is a coordination complex "consisti ...

cofactors.

Iron-sulfur protein Iron–sulfur proteins (or iron–sulphur proteins in British spelling) are proteins characterized by the presence of iron–sulfur clusters containing sulfide-linked di-, tri-, and tetrairon centers in variable oxidation states. Iron–sulfur cl ...

s, including those that are enzymes, are not included in this definition. Some of non-heme iron proteins contain one Fe at their active sites, others have pairs of Fe centers: *Many mono-Fe proteins are

alpha-ketoglutarate-dependent hydroxylases Alpha-ketoglutarate-dependent hydroxylases are a major class of non-heme iron proteins that catalyse a wide range of reactions. These reactions include hydroxylation reactions, demethylations, ring expansions, ring closures, and desaturations. Func ...

. Major examples are the

lipoxygenase Lipoxygenases () are a family of (non-heme) iron-containing enzymes most of which catalyze the dioxygenation of polyunsaturated fatty acids in lipids containing a cis,cis-1,4- pentadiene into cell signaling agents that serve diverse roles as aut ...

isopenicillin N synthase Isopenicillin N synthase (IPNS) is a non-heme iron protein belongig to the 2-oxoglutarate (2OG)-dependent dioxygenases oxidoreductase family. This enzyme catalyzes the formation of isopenicillin N from δ-(L-α-aminoadipoyl)-L-cysteinyl-D-valin ...

, protocatechuate 3,4-dioxygenase, deacetoxycephalosporin-C synthase, and aromatic amino acid hydroxylases.

*Major diiron enzymes include

hemerythrin Hemerythrin (also spelled haemerythrin; grc, αἷμα, haîma, blood, grc, ἐρυθρός, erythrós, red) is an oligomeric protein responsible for oxygen (O2) transport in the marine invertebrate phyla of sipunculids, priapulids, brachiop ...

, some ribonucleotide reductases, some

methane monooxygenase Methane monooxygenase (MMO) is an enzyme capable of oxidizing the C-H bond in methane as well as other alkanes. Methane monooxygenase belongs to the class of oxidoreductase enzymes (). There are two forms of MMO: the well-studied soluble form (s ...

purple acid phosphatases Purple acid phosphatases (PAPs) () are metalloenzymes that hydrolyse phosphate esters and anhydrides under acidic condition. In their oxidised form, PAPs in solution are purple in colour. This is due to the presence of a dinuclear iron centre, to ...

, and

ferritin Ferritin is a universal intracellular protein that stores iron and releases it in a controlled fashion. The protein is produced by almost all living organisms, including archaea, bacteria, algae, higher plants, and animals. It is the primary ' ...

.{{cite journal , doi=10.1021/cr9500489, title=Dioxygen Activation by Enzymes Containing Binuclear Non-Heme Iron Clusters, year=1996, last1=Wallar, first1=Bradley J., last2=Lipscomb, first2=John D., journal=Chemical Reviews, volume=96, issue=7, pages=2625–2658, pmid=11848839 : O2+hemerythrin

References

Enzymes