Nitrite Causes Nitrosative Stress to Iron Sulfur Clusters

Area of Science:

• Biochemistry
• Inorganic Chemistry
• Cellular Signaling

Background:

• Nitric oxide (NO) is crucial for cellular signaling and immune responses.
• Iron sulfur (FeS) clusters are known targets for NO-induced degradation, acting as cellular sensors.
• FeS cluster reactivity was previously thought to be specific to NO, not its precursor, nitrite.

Purpose of the Study:

• To investigate the reactivity of synthetic iron sulfur (FeS) clusters with nitrite.
• To demonstrate that FeS clusters can be nitrosylated by nitrite in the presence of a reductant.
• To synthesize and characterize a mononitrosylated Fe4S4 cluster for further studies.

Main Methods:

• Synthesis of supported synthetic FeS clusters.
• Reaction of FeS clusters with nitrite and a reductant.
• Characterization of the mononitrosylated Fe4S4 cluster.

Main Results:

• Synthetic FeS clusters undergo facile nitrosylation by nitrite with a reductant.
• This demonstrates nitrite reductase activity for FeS clusters.
• A mononitrosylated Fe4S4 cluster, [tempS3Fe4S4(NO)]2-, was successfully synthesized.

Conclusions:

• Iron sulfur clusters exhibit reactivity towards nitrite, expanding their known sensing capabilities.
• This discovery provides a new pathway for understanding cellular responses to NO precursors.
• The synthesized nitrosylated FeS cluster facilitates research into FeS cluster repair and decomposition mechanisms.