NOS2 is expressed primarily in macrophages after induction by cytokines and microbial products, notably interferon-gamma (IFN-γ) and lipopolysaccharide (LPS).
Reactive nitrogen species are also continuously produced in plants as by-products of aerobic metabolism or in response to stress.
[6] Peroxynitrite itself is a highly reactive species which can directly react with various biological targets and components of the cell including lipids, thiols, amino acid residues, DNA bases, and low-molecular weight antioxidants.
Important reactions involving RNS include: Peroxynitrite can react directly with proteins that contain transition metal centers.
All of these reactions affect protein structure and function and thus have the potential to cause changes in the catalytic activity of enzymes, altered cytoskeletal organization, and impaired cell signal transduction.