Hemin
Encyclopedia
Hemin is an iron
-containing porphyrin
. More specifically, it is Protoporphyrin IX
containing a ferric
iron ion (Heme B
) with a chloride
ligand.
It is used in the management of porphyria
attacks, particularly in acute intermittent porphyria
.
It is sometimes distinguished from Hematin which has a hydroxide
ligand in place of the chloride. However, the terms are sometimes equated.
Hematin is considered the "X factor" required for the growth of Haemophilus influenzae
.
Iron
Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...
-containing porphyrin
Porphyrin
Porphyrins are a group of organic compounds, many naturally occurring. One of the best-known porphyrins is heme, the pigment in red blood cells; heme is a cofactor of the protein hemoglobin. Porphyrins are heterocyclic macrocycles composed of four modified pyrrole subunits interconnected at...
. More specifically, it is Protoporphyrin IX
Protoporphyrin IX
Protoporphyrin IX, in the metabolism of porphyrin, is created by the enzyme protoporphyrinogen oxidase.-Heme b biosynthesis:In heme biosynthesis, the enzyme ferrochelatase converts it into heme b Protoporphyrin IX, in the metabolism of porphyrin, is created by the enzyme protoporphyrinogen...
containing a ferric
Ferric
Ferric refers to iron-containing materials or compounds. In chemistry the term is reserved for iron with an oxidation number of +3, also denoted iron or Fe3+. On the other hand, ferrous refers to iron with oxidation number of +2, denoted iron or Fe2+...
iron ion (Heme B
Heme b
Heme B or haem B is the most abundant heme, both hemoglobin and myoglobin are examples of oxygen transport proteins that contain heme B. The peroxidase family of enzymes also contain heme B...
) with a chloride
Chloride
The chloride ion is formed when the element chlorine, a halogen, picks up one electron to form an anion Cl−. The salts of hydrochloric acid HCl contain chloride ions and can also be called chlorides. The chloride ion, and its salts such as sodium chloride, are very soluble in water...
ligand.
It is used in the management of porphyria
Porphyria
Porphyrias are a group of inherited or acquired disorders of certain enzymes in the heme bio-synthetic pathway . They are broadly classified as acute porphyrias and cutaneous porphyrias, based on the site of the overproduction and accumulation of the porphyrins...
attacks, particularly in acute intermittent porphyria
Acute intermittent porphyria
Acute intermittent porphyria is a rare autosomal dominant metabolic disorder affecting the production of heme, the oxygen-binding prosthetic group of hemoglobin. It is characterized by a deficiency of the enzyme porphobilinogen deaminase. Acute intermittent porphyria is the second most common...
.
It is sometimes distinguished from Hematin which has a hydroxide
Hydroxide
Hydroxide is a diatomic anion with chemical formula OH−. It consists of an oxygen and a hydrogen atom held together by a covalent bond, and carrying a negative electric charge. It is an important but usually minor constituent of water. It functions as a base, as a ligand, a nucleophile, and a...
ligand in place of the chloride. However, the terms are sometimes equated.
Hematin is considered the "X factor" required for the growth of Haemophilus influenzae
Haemophilus influenzae
Haemophilus influenzae, formerly called Pfeiffer's bacillus or Bacillus influenzae, Gram-negative, rod-shaped bacterium first described in 1892 by Richard Pfeiffer during an influenza pandemic. A member of the Pasteurellaceae family, it is generally aerobic, but can grow as a facultative anaerobe. H...
.
External links
- Information from the American Porphyria Foundation, including emergency delivery information
- Hemin at RxList