CPOX Human

CPOX is a homodimeric enzyme, meaning it consists of two identical subunits. Each subunit contains two internally bound iron atoms, which are essential for its catalytic activity . The enzyme operates through two sequential steps of oxidative decarboxylation, converting the propionic acid side chains on rings A and B of coproporphyrinogen III to vinyl groups, thus producing protoporphyrinogen IX .

The human CPOX gene spans approximately 14 kb and contains seven exons located on chromosome 3q11.2 . Variants of this gene, such as CPOX4, have been identified and studied for their biochemical properties and susceptibility to environmental toxins like mercury . These variants can affect the enzyme’s affinity and catalytic efficiency, potentially leading to impaired heme biosynthesis and increased susceptibility to neurological deficits .

Mutations in the CPOX gene can lead to a condition known as hereditary coproporphyria. This genetic disorder results in a reduced production of heme, causing a buildup of porphyrin precursors in the body. Symptoms of hereditary coproporphyria can include abdominal pain, neurological disturbances, and photosensitivity .

Recombinant human CPOX is produced using genetic engineering techniques. The gene encoding CPOX is cloned into an expression vector, which is then introduced into a suitable host cell, such as E. coli or yeast. The host cells express the enzyme, which can be purified and used for various research and clinical applications .

Recombinant CPOX is used in biochemical studies to understand the enzyme’s function and regulation. It is also employed in clinical diagnostics to measure enzyme activity in patients suspected of having porphyrias. Additionally, recombinant CPOX can be used in drug development to screen for potential inhibitors or modulators of the enzyme .