Human Vitamin B6 ELISA kit

Vitamin B₆ (VB₆) is an important water-soluble B vitamin composed of six forms: pyridoxine, pyridoxal, pyridoxamine, pyridoxine phosphate, pyridoxal phosphate, and pyridoxamine phosphate. Of these, pyridoxal phosphate (PLP) is biologically active and pyridoxamine phosphate (PMP) is active only to a lesser extent. PLP, as an active small molecule in living organisms, participates in various metabolic processes in the form of coenzymes. Some researchers have found that the combination of PLP and metals can substitute for enzymatic transamination reactions during early evolution in nature, and these results demonstrate that PLP, as a common coenzyme, can act as a catalyst for metabolic reactions even in the absence of enzymes.

Figure 1. Forms of vitamin B₆
(Source: Stach K, et al. 2021)

In the human gut, only the non-phosphorylated form of VB₆ can enter the intestinal cells, after which it is phosphorylated in the liver. The six forms of VB₆ have different transport forms in different cells. Meanwhile, PLP, as an active small molecule in the human body, assists enzymes in the form of coenzymes involved in neurotransmitter synthesis, folate synthesis, heme biosynthesis, and single-carbon unit transfer, thus promoting nucleic acid biosynthesis, sphingolipid synthesis, and carbohydrate metabolism. VB₆ has also been linked to diabetes, heart disease, cancer, cardiovascular and many other diseases. In addition, VB₆ can be used in clinical therapy. In COVID-19 patients, PLP helps to inhibit cytokine storm with inflammation in some patients.

There are 2 different pathways for the de novo synthesis of VB₆ in organisms, the deoxyxylulose 5-phosphate (DXP)-dependent pathway and the non-dependent pathway. The DXP-dependent pathway is predominantly found in α- and γ-protein bacteria such as the gram-negative model bacterium Escherichia coli. The DXP non-dependent biosynthetic pathway involves only the PLP synthase complex (PdxST) and is found in the Gram-positive model bacteria Bacillus subtilis, fungi, protozoa, archaea and plants. To date, no organisms with both VB₆ de novo synthesis pathways have been identified, and many organisms, including humans and other mammals, have only remedial pathways in which VB₆ is interconverted.

Human VB6 ELISA kit