Page 275 - Biochemistry PharmD General

Biosynthesis of heme

• Heme is an iron porphyrin structure, synthesized in the
reticuloendothelial cells (bone marrow) of adult human being.
Erythropoietin produced in kidney stimulates the formation,
maturation and release of erythrocytes by bone marrow.

• Early stage of erythrocyte cells contain porphyrin, during the
course of their development, porphyrin is converted to heme by
addition of iron and then to hemoglobin by addition of protein,
globin. The type of porphyrin present in heme is protoporphyrin-
III (also known as No. IX).

• It is synthesized starting from glycine and succinyl-CoA. Given
below is the diagrammatic representation of biosynthesis of Heme
where ‘A’ stands for acetyl group, ‘P’ stands for propyl group, ‘M’
for methyl group, and ‘V’ for venyl group.

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