Peroxynitrite: Toxic Agent and Signaling Molecule (Review)
Yu. V. Abalenikhina, O. V. Kosmachevskaya, А. Ф. Топунов
Abstract
Abstract Peroxynitrite, a reactive nitrogen species, is one of the strongest oxidants in the body. Depending on the conditions, it either undergoes biotransformation and detoxification or interacts with various compounds (proteins, including enzymes; lipids, nucleic acids, and carbohydrates) and modifies them. Thiols, including cysteine residues in proteins, are most actively exposed to peroxynitrite. The inhibitory effect of peroxynitrite on enzymes was best described for oxidoreductases, in which it also most often acted on cysteine. Modified biomolecules can be toxic; however, at physiological concentrations, they are able to function as members of signaling pathways. The described data show that peroxynitrite is not only a toxic agent but also a component of the messenger system and a signaling molecule responsible for the redox regulation of cellular metabolism. The detoxification pathways are important aspects in the study of peroxynitrite and may facilitate the search for medicinal agents against diseases accompanied by nitrosative stress.