149 10.71 Vitamin B6 Functions
PLP is a cofactor for over 100 different enzymes, most are involved in amino acid metabolism. In fact, without PLP, all amino acids would be essential because we would not be able to synthesize nonessential amino acids. Below are some of the functions of PLP and PMP1:
PLP is required for decarboxylase enzymes that are involved in the synthesis of the neurotransmitters GABA, serotonin, histamine, and dopamine. As an example, DOPA decarboxylase uses PLP to convert L-DOPA to dopamine as shown below1.
PLP is also required by gamma-aminolevulinic acid (ALA) synthetase that is involved in heme synthesis, as shown below. Heme will be discussed in more detail in the iron section.
PLP is also used in one of the multiple reactions that occurs between kynurenine and niacin in its synthesis from tryptophan.
In addition, PLP is also involved in:
Carnitine Synthesis
1-Carbon Metabolism
References & Links
1. Gropper SS, Smith JL, Groff JL. (2008) Advanced nutrition and human metabolism. Belmont, CA: Wadsworth Publishing.
2. http://en.wikipedia.org/wiki/File:Transaminierung.svg
3. http://en.wikipedia.org/wiki/File:DesaminierungCtoU.png
4. http://en.wikipedia.org/wiki/File:Catecholamines_biosynthesis.svg
5. http://en.wikipedia.org/wiki/File:Heme_synthesis.png
6. https://commons.wikimedia.org/wiki/File:Nicotinic_acid_biosynthesis2.png