Hemeprotein
A hemoprotein, a protein capable of binding a ligand heme. Häme are constantly bound to the protein, either covalently, non-covalently, or both.
The heme containing a reduced iron atom ( Fe2 ) in the middle of a highly hydrophobic, flat porphyrin complex. The iron has six possible coordination compounds. The porphyrins ring has four nitrogen atoms, which combine with the iron, the two coordination compounds can be open to the connection with the histidine of the protein and a bivalent atom.
Heme proteins probably evolved to accommodate the iron atom, which is included in protporphyrinen IX ring of heme to ask this in proteins. Since this enables hemoproteins as the connection partner for molecules with divalent iron, this strategy has been retained in the evolution as it plays an essential role in physiological function. Oxygen, nitric oxide, carbon monoxide and hydrogen sulfide can bind to the iron atom in heme proteins. When these elements have been connected to the porphyrin complex, these molecules can modulate the activity or functionality of hemoproteins and to ensure the signal transduction. These gaseous molecules are referred to as Gasotransmitter for this purpose.
Because of their diverse biological functions, structural and functional Charakterisation the hemoproteins are the most studied group of biomolecules. For purposes of global analysis of the data of heme proteins and their structural formulas they were bundled into a source of Hämoproteindatenbank HPD.
Occurrence and species
Heme proteins have diverse biological functions:
- Oxygen transporter hemoglobin
- Myoglobin
- Neuroglobin
- Cytoglobin
- Leghaemoglobin
- Peroxidases
- Cytochrome c oxidase
- Ligninase
- Cytochrome
- Cytochrome c
- FixL
- SGC
- CooA
- Catalase
Hemoglobin and Myoglobin
Hemoglobin and myoglobin are examples of hemoproteins which are necessary for the storage and the transport of oxygen in mammals. Hemoglobin is a quaternary protein that occurs in the red blood cells as myoglobin is a tertiary protein found in muscle cells of mammals. Although the two proteins differ in location and size, its function is similar. As heme proteins both contain a prosthetic group.