During the project we have identified bacterial and mammalian oxidation-sensitive subset of the proteome by MS. Furthermore, the aggregates formed by the oxidized proteins within the mammalian cells were characterized using FTIR microscopy, AFM and cell fractionation experiments. Interaction with the membranes was analyzed for the total cellular aggregates and aggregates formed by a recombinant protein using STED microscopy and biochemical assays based on cell fractionation and floatation on sucrose density gradients. The recombinant protein used in this work was superoxide dismutase 1 (SOD1), a protein implicated in amyotrophic lateral sclerosis (ALS) which represents a typical age-related neurodegenerative disease. While the oxidized and non-oxidized cellular aggregates bound membranes in a similar manner, oxidized recombinant SOD1 had different affinity for the artificial membranes relative to its non-oxidized counterpart. Moreover, aggregates formed by the oxidized and non-oxidized SOD1 differed in their ability to perforate membranes, as well as in their cellular toxicity. In search for the agents that could protect the cells from the toxic oxidized protein aggregates, we found that the presence of certain lipids in the artificial membranes was protective against all kinds of aggregates, and some other lipids were protective against oxidative damage of the cells. Finally, we identified antioxidants as the most efficient in preventing protein oxidation in the cells.
Various parts of these results were presented to the scientific community in one peer-reviewed publication, as well as at one local (Life Science Club in Split, Croatia) and three international conferences (IMCAS in Paris, France; Advances in Biomedical Research in Split, Croatia; and ABMBBIH in Sarajevo, BiH) in the form of oral or poster presentations. Furthermore, the results were communicated at two smaller meeting with other institutions, during one invited lecture in Slovenia, and at numerous internal meetings. The main messages of our work were also shared with broader audience during three local outreach events, and the basic project information were featured on social media, project website and within an interview at an internet portal of a Serbian radio station. Future exploitation of the results was secured through establishing connections with a French cosmetic company.
