As haemoglobin decomposes it transforms into a green pigment called biliverdin
, which then converts into a yellow or light brown one called bilirubin.
Hemoglobin molecules degradation to its product, heme, Iron, biliverdin
and bilirubin may lead to oxidativ stress (14).
HO is a rate-limiting enzyme responsible for the catabolism of heme into carbon monoxide (CO), ferrous iron, and biliverdin
, which converted to bilirubin.
According to scientists, all of this happens due to high levels of biliverdin
, a green bile pigment which overshadows the crimson coloration of red blood cells and is toxic to humans.
It contains three different copper centers (T1, T2, and T3) with overall four copper ions that catalyze the oxidation of bilirubin to biliverdin
, thereby reducing molecular oxygen to water.
The microsomal fraction (50 [micro]L) was added to the reaction mixture (500 [micro]L) containing 0.8 mM NADPH, 2 mM glucose-6-phosphate, 0.2 unit of glucose-6-phosphate dehydrogenase, 20 [micro]M hemin, 100 mM potassium phosphate buffer (pH 7.4), and 2mg of rat liver cytosol as a source of biliverdin
HMOX1 is a cytoprotective enzyme that catalyzes hepatic heme breakdown to produce biliverdin
, carbon monoxide (CO), and ferrous iron.
HO-1 generates biliverdin
IX[alpha], ferrous iron, and CO from the oxidation of heme, and exhaled CO reflects active heme metabolism .
Heme oxygenase-1 (HO-1) is an intracellular enzyme that catalyzes the oxidation of heme to generate carbon monoxide (CO), biliverdin
, and ferrous iron.
Due to the effects of heme oxygenase (HO), which contain two forms: HO-1 and HO-2, cyclic tetrapyrrole heme is divided into biliverdin
, carbon monoxide (CO), and ferrous iron ([Fe.sup.2+]).
Attanasio et al., "Biliverdin
protects against liver ischemia reperfusion injury in swine," PLoS One, vol.
in liver and spleen samples from multiple avian species.