Physiological Functions and Attack Points of NO

The physiological importance of NO is due to both its regulatory and its toxic functions (review Stamler, 1994). 

The toxic action of NO has an important role, especially in nerve systems. It is assumed that during a stroke, for example, excess production of NO leads to death of nerve cells. Direct modification of ligand-gated ion chaimels, such as the receptor for N-methyl-D-aspartate (NMDA receptor), by NO has a special role in coimection with this. 

NO-mediated functions are described for the following processes in particular (review Schmidt and Walter, 1994)  

Due to its high reactivity, NO can interact and react with many effector proteins. Targets are proteins with boimd metal ions and specific cysteine residues of proteins. In Table 6.3, some important bioregulatory proteins are summarized, for which direct modification by NO is assumed. Two target proteins should be mentioned in particular  

Proteins are included for which a direct regulation by NO is assumed (according to Stammler, 1994). Direct evidence of regulatory nitrosylation has only been shown for hemoglobin, however. 

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