"Pyridoxal phosphate" perform which step of amino acid transformation During protein metabolism
Answers
Answer:
Pyridoxal phosphate (PLP) is a pyridine derivative, carries a free aldehyde as a functional group and is synthesized in most micro-organisms and plants. It has been suggested that acetaldehyde, dihydroxyacetone phosphate and d-glyceraldehyde-3-phosphate figure as precursors . The resulting pyridoxol-phosphate is reduced to PLP. Pyridoxin, pyridoxal and pyridoxamine act as vitamins (vitamin B6) and are transformed to PLP. PLP is the cofactor of aminotransferases and amino acid decarboxylases which play a central role in the metabolism of nitrogenous compounds. It is covalently, although reversibly, bound to a lysine of the active center. As the main reaction, a Schiff's base is formed between the aldehyde of PLP and the amino group amino acids . The pyridine nitrogen atom is a strong electrophile and induces the displacement of a pair of electrons adjacent to the α-carbon of the respective amino acid, resulting in the loss of a substituent at the α-C atom. Depending on the enzyme involved, the same cofactor can mediate quite different reactions, i.e. decarboxylation and transamination.
Explanation: