Here, using <i>in vitro</i> biochemical assays with purified, recombinant protein, along with experiments in the adenocarcinoma cell line A431, we discovered that bicarbonate, which reacts with H<sub>2</sub>O<sub>2</sub> to form the more reactive peroxymonocarbonate, potently facilitates H<sub>2</sub>O<sub>2</sub>-mediated PTP1B inactivation in the presence of thioredoxin reductase 1 (TrxR1), thioredoxin 1 (Trx1), and peroxiredoxin 2 (Prx2) together with NADPH.
This human inducible NOS possessed consensus recognition sites for the cofactors FMN, FAD, and NADPH and calmodulin recognition sites, and displayed 48.1% sequence identity with the endothelial type, 43.1% with the neuronal type, and 99.3% with the inducible type from hepatocytes, and 99.9% with the inducible type from chondrocytes and adenocarcinoma.