Enzymatic Targets of Nitric Oxide as Detected by EPR Spectroscopy within Mammal Cells

We concluded in chapter 6 that all metalloproteins are potential targets of NO, as proven by EPR spectroscopy, which is too unspecific to be a really interesting statement. We now turn to some more biologically relevant aspects of NO binding. Its production from L-arginine catalyzed by the inducible NO-synthase (iNOS, NOS II) in murine macrophages and their tumoral target cells was the simplest case to characterize at the molecular level by EPR spectroscopy. [FeS]-containing proteins and ribonucleotide reductase responsible for basic vital cellular functions such as mitochondrial respiration and DNA replication were the earliest enzymatic targets characterized in whole cultured mammal cells.