Heme oxygenase: Difference between revisions

'''Heme Oxygenase''' (HO) is a member of the Hemoprotein family and catalyzes the Oxygen-dependent cleavage of the porphyrin ring of heme, using reducing equivalents like NADH to produce biliverdin, iron and CO <ref name="HO">PMID:17253780</ref>. HO consists of two main isoforms which are present in mammals, HO-1 and HO-2. The two isoforms are products of different genes, are different molecular sizes (32 kDa and 36 kDa respectively) and contain a different primary structure showing only 58% homology <ref name="HO1">PMID:15522396</ref>. However studies have shown that the two isoforms share a region with 100% secondary structure homology which is believed to be the catalytic site of the protein<ref name="HO"/>. The heme oxygenase isoforms are not free throughout the body but sequestered to certain tissues. The Heme oxygenase -1 is strongly expressed in the spleen and liver whereas Heme Oxygenase-2 is strongly expressed in the brain, testis and vascular systems<ref name="sc1">PMID:12909459</ref>.