Chemistry Reference
In-Depth Information
OTHER IRON-CONTAINING PROTEINS
There are many other proteins that contain iron in a form which is neither in haem nor in iron
sulfur clusters.
We have already encountered the iron-storage and transport proteins, ferritin and transferrin (Chapter 8). We
propose to discuss here two other classes of iron-containing proteins, those with mononuclear nonhaem iron
centres and those with dinuclear nonhaem iron centres. The mononuclear nonhaem iron enzymes include
a large number of enzymes involved in oxygen activation and insertion into organic substrates. We can
distinguish between enzymes with a mononuclear high-spin Fe(II) centre and those with a mononuclear Fe(III)
centre.
The mononuclear Fe(II) enzymes catalyse a wide variety of reactions and have been classified into five families
(
Figure 13.20
)
.
e
FIGURE 13.20
Reactions catalysed by each of the five families of mononuclear nonhaem iron enzymes with a 2-His-1-carboxylate facial
triad. Dioxygen is labelled to indicate the fate of each oxygen atom.
(Adapted from
Koehntop, Emerson, & Que, 2005
.)
