Director of studies: Dr. Anna Palumbo
Department of Biology and Evolution of Marine Organisms
Project Summary/Abstract
The marine environment is characterized by a high biodiversity of species, which accounts for the enormous chemical diversity representing a great potential source of bioactive molecules. There is a great interest in exploiting the biological properties and biotechnological applications of marine compounds, as molecules with antioxidant activities. Among these, a new class of sulfur-containing amino acids, thiohistidine derivatives, termed ovothiols, was isolated and characterized from sea urchin eggs in the eighties at the Zoological Station. Recently, the enzyme responsible for the first step of its biosynthesis, 5-histidylcysteine sulfoxide synthase (Ovo), has been characterized. In silico studies have revealed the presence of homologous Ovo enzymes in more than 80 genomes, ranging from proteobacteria to animalia, suggesting a variety of roles played by this metabolite. Interestingly, ovothiol has been shown to be a promising pharmacological compound, being active on cancer cells and as neuroprotectant. The main objective of this study is to investigate, through a multidisciplinary approach, spanning from developmental biology to algal physiology, the biological activities of ovothiol in two different marine organisms inhabiting coastal seas, as the invertebrate sea urchin and microalgae from the diatoms’group.
The ability of diatoms, target species already studied and cultivated at the Zoological Station, to activate antioxidant activities expressing Ovo will be investigated in laboratory under different stress conditions and growth phases. In parallel, the involvement of this metabolite in stress response of the sea urchin Paracentrotus lividus will be examined exposing developing embryos to a series of chemical and physical stress agents and monitoring Ovo expression and ovothiol formation, using protocols already established in our group. Gene perturbation experiments will be performed on sea urchin and diatoms to assess the functional significance of ovothiol formation in both organisms.
Intellectual Merit
The proposed project will expand the knowledge about the biological properties of a marine natural product which can then drive future applicative studies. The expected impact will provide a better understanding of the ecophysiological functioning of coastal ecosystem submitted to environmental stresses, targeting both the pelagic and benthic systems.
Moreover, results obtained on the ovothiol production by diatoms are of huge interest in a biotechnological context, allowing to produce this molecule at low cost.
Broader Impacts
The study of the biological properties of ovothiols has the potential to impact other fields, e.g. nutraceutical. The antioxidant properties of this class of compounds might be exploited in the formulation of nutritional supplements.
