Lysyl oxidase

Each monomer consists of an active site that includes a Cu(II) atom, coordinated by three histidine residues, as well as 2,4,5-trihydroxyphenylalanine quinone (TPQ), a crucial cofactor.

The DNA sequence encodes a polypeptide of 417 amino acids, the first 21 residues of which constitute a signal peptide,[6] with a weight of approximately 32 kDa.

Molecular oxygen and the copper ion are utilized to reoxidize the cofactor, producing hydrogen peroxide as a side product.

[14] Lysyl oxidase is an extracellular copper-dependent enzyme that catalyzes formation of aldehydes from lysine residues in collagen and elastin precursors.

[18] This resulted in lathyrism, characterized by poor bone formation and strength, hyperextensible skin, weak ligaments, and increased occurrence of aortic aneurysms.

[19] Developmentally, reduced lysyl oxidase activity have been implicated in Menkes disease and occipital horn syndrome, two X-linked recessive disorders characterized by a mutation in a gene coding for a protein involved in copper transport.

[24] LOX expression was also detected in megakaryocytes, or bone marrow cells responsible for the production of platelets.

In a rodent model of breast cancer, a small-molecule or antibody inhibitors of LOX abolished metastasis.

[26] In cells lacking TGF-β receptors, a deficiency that is characteristic of lung cancer, lysyl oxidase is found in high concentrations.

[27] Lysyl oxidase has been newly implicated in tumor angiogenesis, or blood vessel formation, both in vivo and in vitro.

Lysyl oxidase-catalyzed oxidation of a lysine residue to allysine residue.
Mechanism of the oxidation of the side chain of lysine residues by the action of LTQ. The lysyl oxidase participates in the regeneration of the quinone.