UC Santa Cruz

Peroxynitrite is a reactive nitrogen species that has remained at the center of controversy since the time of its discovery in the early 1990’s. The reactive nature of PN required unique chemical synthetic approaches and techniques to be developed to study the chemistry of this species. Unfortunately, many of these sources are highly alkaline, produce unwanted byproducts, and can be difficult to control. With these shortcomings in mind, a multi-well platform was designed and constructed that is capable of evolving sustained levels of peroxynitrite precursors nitric oxide and superoxide under controlled conditions. Nitric oxide and superoxide rapidly react in the wells of the platform to generate peroxynitrite in situ. This thesis describes the design process and construction of this biomimetic two-component peroxynitrite-generating system.

In Chapter 2 the fabrication and characterization of the platform is discussed in detail and concludes with results obtained were intrinsic platform probe uric acid was used to effectively demonstrate the control of the system. The work highlighted in Chapter 3 establishes the application of the platform through the use of PN-target tyrosine. Investigation into PN-mediated nitration of free tyrosine and tyrosine-containing model peptides within the wells of the platform revealed extents of nitration (~40 %) significantly greater than values previously reported in the literature where alternative sources of PN were employed. Chapter 4 describes our first attempts to study an unexplored chemistry between peroxynitrite and 3-nitrotyrosine within the wells of the platform. Results from this work revealed a unique dimer product that was characterized by detailed mass spectral analysis.

Based on the results of Chapters 2, 3 and 4, the designed platform has been firmly established as a powerful bioanalytical tool. Recognizing this potential, Chapter 5 describes preliminary results observed in recent studies investigating the metabolites of selected anti-inflammatory drugs upon exposure to peroxynitrite and its precursors nitric oxide and superoxide. Descriptions of the results are presented with the intentions of establishing a future direction for the peroxynitrite-generating platform.