The award in the Inorganic, Bioinorganic and Organometallic Chemistry program supports research by Professor Pradip K. Mascharak at the University of California at Santa Cruz to synthesize new non-heme iron, ruthenium and manganese nitrosyls that will release NO upon illumination at various wavelengths of light. The spectroscopic and electronic properties of these complexes will be explored in order to determine what factor(s) promote the photolability of NO and their structures will be determined. A set of guiding principles and a series of ligands designed after the metal-binding domain of the enzyme nitrile hydratase, which is photoregulated through NO binding, will be utilized in the syntheses of these metal nitrosyls. In addition, redox and magnetic measurements will be performed on both photoactive and inactive metal nitrosyls to elucidate the origin of the photolability of NO bound at these metal centers in different oxidation states. Theoretical calculations will also be performed to gather further insight into this process. The mechanisms of the light-induced NO release will be explored and the capacities of the nitrosyl complexes to transfer NO to various biologically relevant substrates, such as glutathione and proteins, will be measured.
This research aims at identifying the chemical architectures and the associated electronic features that provide for the photolability of NO. Such nitrosyl complexes will provide the biochemists with a tool to study the kinetics of NO binding (and inhibition) to heme and non-heme proteins by optical spectroscopy. The results of this research work will provide valuable chemical insights toward syntheses of inorganic NO donors as photochemotherapeutics. This research also provides an opportunity for graduate and undergraduate students to participate in systematic goal-oriented research at the interface of chemistry and biology.
