Aurintricarboxylic acid

Aurintricarboxylic acid (ATA) is a chemical compound that readily polymerizes in aqueous solution, forming a stable free radical that inhibits protein-nucleic acid interactions. It is a potent inhibitor of ribonuclease and topoisomerase II by preventing the binding of the nucleic acid to the enzyme. It stimulates tyrosine phosphorylation processes including the Jak2/STAT5 pathway in NB2 lymphoma cells, ErbB4 in neuroblastoma cells, and MAP kinases, Shc proteins, phosphatidylinositide 3-kinase and phospholipase Cγ in PC12 cells. It also inhibits apoptosis. It prevents down-regulation of Ca²⁺-impermeable GluR2 receptors and inhibits calpain, a Ca²⁺-activated protease that is activated during apoptosis.

It is used to inhibit protein biosynthesis in its initial stages. Nominally, it is used in biological experiments as a protein inhibitor, and as an ammonium salt (known as aluminon) it is used as a reagent to estimate the aluminium in water, biological tissue, and foods.

It was found that ATA is a strong inhibitor of topoisomerases and other nucleases. It might be useful for increasing efficiency of RNA isolation.

It has been discovered that using aurintricarboxylic acid against influenza-A post-infection has a strong protective effect by inhibiting the virus' ability to reproduce. In cultured canine kidney cells, it was found to reduce viral reproduction and infection when applied post-infection, but not when used as a 'vaccine'. It has also been shown to block the binding of the HIV coat molecule gp120 to the CD4 co-receptor on T cells through which it invades.