Pyridoxine 4-dehydrogenase

Pyridoxine 4-dehydrogenase

Pyridoxine 4-dehydrogenase is an enzyme that plays a crucial role in the metabolism of pyridoxine, also known as vitamin B6. It catalyzes the conversion of pyridoxine to pyridoxal, an important step in the synthesis of the active form of vitamin B6.

Structure

Pyridoxine 4-dehydrogenase is a protein composed of amino acids. It is typically found in the cytoplasm of cells, although it can also be present in other cellular compartments. The enzyme consists of a single polypeptide chain, folded into a three-dimensional structure that allows it to carry out its catalytic function.

Function

The primary function of pyridoxine 4-dehydrogenase is to convert pyridoxine to pyridoxal. This reaction involves the removal of two hydrogen atoms from pyridoxine, resulting in the formation of pyridoxal and two hydrogen ions. Pyridoxal is then further metabolized to its active form, pyridoxal phosphate, which is a cofactor for many enzymes involved in various metabolic pathways.

Role in Vitamin B6 Metabolism

Vitamin B6, in its active form as pyridoxal phosphate, is essential for numerous biochemical reactions in the body. It is involved in amino acid metabolism, neurotransmitter synthesis, and the production of red blood cells. Pyridoxine 4-dehydrogenase is a key enzyme in the conversion of pyridoxine to pyridoxal, which is a crucial step in the synthesis of pyridoxal phosphate.

Clinical Significance

Mutations in the gene encoding pyridoxine 4-dehydrogenase can lead to a deficiency in the enzyme's activity. This deficiency can result in a condition known as pyridoxine-dependent epilepsy, characterized by seizures that can only be controlled with high doses of pyridoxine supplementation. This highlights the importance of pyridoxine 4-dehydrogenase in maintaining normal vitamin B6 metabolism and neurological function.

References

1. Dawson R.M.C., et al. (2009). "Pyridoxine 4-dehydrogenase". In: Data for Biochemical Research. Oxford: Oxford University Press.

2. Mills P.B., et al. (2006). "Pyridoxine-dependent epilepsy due to mutations in the pyridoxine-4-dehydrogenase gene: report of a family with normal 4-pyridoxic acid concentration in cerebrospinal fluid despite cerebrospinal fluid pleocytosis". Pediatrics, 118(2):e430-4.

See Also

• Vitamin B6
• Pyridoxal
• Pyridoxal phosphate
• Enzyme
• Metabolism