Amine oxidase copper-containing 3 (AOC3) (SSAO)

Amine oxidase copper-containing 3 (AOC3), widely known as Semicarbazide-sensitive amine oxidase (SSAO) or Vascular Adhesion Protein-1 (VAP-1), is a bifunctional protein that operates as both a membrane-bound enzyme and a cell adhesion molecule [1, 3]. It is highly expressed in vascular smooth muscle cells, endothelial cells, and adipocytes, where it exists in both tissue-bound and soluble isoforms [2, 4]. The enzyme catalyzes the oxidative deamination of primary amines, such as methylamine and aminoacetone, into their corresponding aldehydes, hydrogen peroxide, and ammonia [1, 9]. These metabolic byproducts are potent mediators of oxidative stress and have been implicated in the pathogenesis of atherosclerosis and diabetic complications [7, 13]. Additionally, as VAP-1, the protein mediates the rolling, adhesion, and transmigration of leukocytes to sites of inflammation [10, 11]. Consequently, AOC3 is a prominent therapeutic target for treating chronic inflammatory conditions and metabolic diseases, with several small-molecule inhibitors having been evaluated in preclinical rat models and clinical trials [11, 15].

Other names

Vascular adhesion protein-1VAP-1Semicarbazide-sensitive amine oxidaseCopper-containing amine oxidase 3HPAOPrimary amine oxidase

Irreversible suicide inhibition of the copper-containing amine oxidase activity through the formation of a stable covalent adduct with the topaquinone cofactor, thereby preventing the generation of cytotoxic metabolites and reducing leukocyte recruitment.