Dinitrosyl Iron Complexes (dnics) Bearing O-bound Nitrito Ligand:reversible Transformation Between The Six-coordinate {fe(no)_2}~9

摘要

Dinitrosyl iron complexes (DNICs), one of the possible forms for storage and transport of NO, have been known to exert NO bioactivity under physiological and pathological conditions. It is proposed that DNICs play a crucial role in regulating iron uptake/ storage, triggering the expression of proteins against nitrosative stress, and reassembling [Fe-S] clusters after nitrosative damage. Characterization of DNICs in vitro/vivo has been made possible via the distinct EPR signal at g = 2.03. Nitrite, an ubiquitous molecule in vivo, particularly in the endocrine system, serves in intravascular NO storage/transport in blood circulation. Nitrite signaling operates through the cooperative action with hemes, thiols, amines, polyphenols, and ascorbate yielding nitric oxide during physiological and pathological hypoxia. In particular, the biotrans-formation of nitroglycerin (GTN) in the presence of cysteine/NADH generating NO and nitrite was proposed to proceed via the nitrite-containing ferrous intermediate (Supporting Information (SI) Scheme S1).