[Metalloproteins, cellular targets of nitric oxide: a concise review].

In this review we recall the main physical properties of nitric oxide. The irreversible reactions of NO with O2 and O2.-, which yield strongly oxydant and nitrosating, and therefore toxic, species, are described in kinetic terms. Nearly all metalloproteins are potential targets for NO, often detectable by EPR spectroscopy. The case of hemoglobin in vitro and within circulating erythrocytes, especially in pathophysiological cases, is particularly described. A few examples of hemoproteins activated or inhibited by NO are given. Results obtained with cellular systems responding to cytokines are summarized, together with the effects of NO synthesis on [FeS] clusters-containing proteins, on ribonucleotide reductase and on the proteins implicated in iron metabolism.