Histidine decarboxylase

From Biology-Online Dictionary | Biology-Online Dictionary



An enzyme that is responsible in the biosynthesis of histamine from histidine that transforms various physiologic processes including gastric acid secretion,smooth muscle tone and neurotransmission.


Histidine decarboxylase gene is mapped on chromosomes 15q21.2 with 662 amino acids that has a molecular mass of 74,148 Da which contains 12 exons spanning at around 24 kb. It is very specific for its histidine substrate due to its pyridoxal phosphate. It is also a member of the group II decarboxylase family and forms homodimer.

Histidine decarboxylase activity is usually expressed in mast cells, histaminergicneurons in brain and endocrine cells in stomach. Deficiency of these enzymes would lead to increase locomotors and stereotypic behaviors as well as augmented anxiety. It is also associated with sodium dodecyl sulphate (SDS) that cause pruritus in human wherein treatment increased the histamine content on the epidermis but not in dermis through gene expression and translation process of histidine decarboxylase in the epidermis.

Histidine decarboxylase in mammals reveals that the active center is more resistant to the formation of substituted aldamines than the prokaryotic homologous enzymes thereby confers a promising new perspective for the development of new and more exact inhibitors with pharmacological potential.

Gene name: HDC

Protein name: Histidine decarboxylase (HDC)

See also:

Aromatic L-amino acid decarboxylase