A
hemoprotein, or
heme protein, is a protein containing a heme prosthetic group, either covalently or noncovalently
bound to the
protein itself. The
iron in the
heme is capable of undergoing
oxidation and
reduction (usually to +2 and +3, though stabilized
ferryl [Fe
+4] compounds are well known in the
peroxidases). Hemoproteins are found in such diverse roles as transport (
hemoglobin,
myoglobin,
neuroglobin[?],
cytoglobin[?] and
leghemoglobin), catalysis (
peroxidases), active membrane transport (
cytochromes), and electron transfer (
cytochrome c).