Heme B
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Other names
Iron protoporphyrin IX,
protoheme IX | |
Identifiers | |
3D model (
JSmol ) |
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ChemSpider | |
ECHA InfoCard
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100.114.904 |
MeSH | Heme+b |
PubChem CID
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UNII | |
CompTox Dashboard (EPA)
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Properties | |
C34H32O4N4Fe | |
Molar mass | 616.487 |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Heme B or haem B (also known as protoheme IX) is the most abundant
Generally, heme B is attached to the surrounding protein matrix (known as the
Both hemoglobin and myoglobin have a coordination bond to an evolutionarily-conserved histidine, while nitric oxide synthase and cytochrome P450 have a coordination bond to an evolutionarily-conserved cysteine bound to the iron center of heme B.
Since the iron in heme B containing proteins is bound to the four nitrogens of the porphyrin (forming a plane) and a single electron donating atom of the protein, the iron is often in a pentacoordinate state. When oxygen or the toxic carbon monoxide is bound the iron becomes hexacoordinated. The correct structures of heme B and heme S were first elucidated by German chemist Hans Fischer.[2]
References
- PMID 30726014, retrieved 2023-01-03
- ^ Fischer, H.; Orth, H. (1934). Die Chemie des Pyrrols. Liepzig: Akademische Verlagsgesellschaft.