porphyrin-containing compound biosynthetic process

Definition

Target type: biologicalprocess

The chemical reactions and pathways resulting in the formation of any member of a large group of derivatives or analogs of porphyrin. Porphyrin consists of a ring of four pyrrole nuclei linked each to the next at their alpha positions through a methine group. [GOC:jl, ISBN:0198506732, Wikipedia:Porphyrin#Natural_formation]

Porphyrin-containing compound biosynthetic process is a complex and essential metabolic pathway that produces heme, a vital component of hemoglobin, myoglobin, and cytochromes. It involves a series of enzymatic reactions that convert simple precursors, glycine and succinyl CoA, into protoporphyrin IX, which then binds to ferrous iron to form heme. The process can be divided into four major stages:

1. **Formation of δ-aminolevulinate:** Glycine reacts with succinyl CoA, catalyzed by δ-aminolevulinate synthase (ALAS), to form δ-aminolevulinate (ALA). This is the rate-limiting step in heme biosynthesis.
2. **Formation of porphobilinogen:** Two molecules of ALA condense to form porphobilinogen (PBG), catalyzed by porphobilinogen deaminase.
3. **Formation of protoporphyrin:** Four molecules of PBG are assembled into a linear tetrapyrrole, which then undergoes a series of enzymatic rearrangements and modifications to form protoporphyrin IX.
4. **Heme formation:** Iron is incorporated into protoporphyrin IX, catalyzed by ferrochelatase, to form heme.

The porphyrin-containing compound biosynthetic process is tightly regulated to ensure adequate heme production without accumulation of potentially toxic porphyrin precursors. Deficiencies in the enzymes involved in this pathway can lead to a variety of human diseases, including porphyrias, characterized by accumulation of specific porphyrin precursors. These diseases can cause a wide range of symptoms, including photosensitivity, neurological disorders, and abdominal pain.'
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Proteins (1)

Compounds (3)