PhD ceremony Ms. R. Wisastra: Modulation of lipoxygenase activity and chemistry-based detection of protein nitration in inflammation
| When: | Fr 24-05-2013 at 11:00 |
PhD ceremony: Ms. R. Wisastra, 11.00 uur, Academiegebouw, Broerstraat 5, Groningen
Dissertation: Modulation of lipoxygenase activity and chemistry-based detection of protein nitration in inflammation
Promotor(s): prof. H.J. Haisma
Faculty: Mathematics and Natural Sciences
The studies in the thesis of Rosalina Wisastra are focused on the development of chemistry-based tools that can be employed to gain a comprehensive understanding of enzyme activity in inflammatory processes in association with the NF-κB pathway. The first part of her thesis describes the development of novel modulators for lipoxygenase (LOX) enzyme activity. Enzyme kinetic studies on these salicylate-based modulators demonstrate that they regulate the lipoxygenase activity by binding to an allosteric regulatory site in lipoxygenses.
The second part describes a detailed investigation of isothiazolone hetercycles, which are thiolate reactive functionalities that can be employed for development of novel probes for activity-based protein profiling (ABPP) of enzymes that play a role in inflammation. A newly resolved crystal structure of the isothiazolone heterocycle demonstrates an aromatic character, which provides stability. In contrast, the weak sulfur-nitrogen bond allows a fast and selective reaction with thiolates to form a strong disulfide bond.
The final part describes the development of a novel convenient staining method for detection of oxidative stress in tissue sections using fluorescence microscopy. This novel method is selective for tyrosine nitration, which is an oxidative protein modification that is frequently observed under inflammatory conditions. This novel method involves the chemical conversion of nitrotyrosine into a fluorophore under mild conditions and proved to be very efficient in histochemical staining of inflamed tissue sections and can also be employed as alternative detection method for immunoblotting on PVDF membranes.