Amine oxidase [copper-containing] 3

AOC3 (amine oxidase [copper-containing] 3) is a copper-dependent enzyme that catalyzes the oxidative deamination of primary amines, particularly methylamine and benzylamine, generating aldehydes, hydrogen peroxide, and ammonia (UniProt: Q16853). Beyond its enzymatic role, AOC3 functions as a cell adhesion protein at endothelial cell surfaces, facilitating lymphocyte extravasation and recirculation through interaction with peripheral lymph node vascular endothelial cells.

AOC3 is expressed on endothelial cells and participates in immune cell trafficking and vascular biology. UniProt records indicate no annotated disease associations in standard curated databases, though the protein's involvement in vascular and immune processes suggests potential relevance to conditions affecting these systems (UniProt: Q16853).

In Alzheimer's Disease, AOC3 shows increased abundance in post-mortem AD brain tissue compared to age-matched controls, with a mean log2 fold-change of 1.14 across examined subcellular fractions (Chaparral AD proteomics). This upregulation may reflect altered amine metabolism or vascular inflammatory responses in the AD brain, though the functional significance of this elevation remains to be determined.