João Guerra

Research Areas

Metalloproteins, bacterial iron and copper homeostasis, structure-function of proteins

PhD Thesis: "Biophysical and Biochemical Characterization of Proteins involved in Transition Metals Homeostasis"

Advisers: Prof.ª Doutora Alice Pereira and Prof. Doutor Pedro Tavares

Transition metals, while present in biological cells at minimal concentrations, are extremely important to the chemistry of living systems. The two transition metals most abundant in biological systems from all domains of life are iron and copper. Iron, the most abundant, is present in many essential proteins and enzymes co-factors such as heme or iron-sulfur clusters. However, free iron is generally insoluble or highly reactive and therefore potentially toxic. As such, cells developed several iron management systems, one of the most notable examples being the proteins from the Ferritin family, capable of storing iron in a soluble, bioavailable and non-toxic form. Similarly, copper is present in the prosthetic groups of many proteins involved in electron transfer, energy production, oxygenases and free radical scavengers. Like iron, copper ions are also toxic when free in solution and intracellular copper storage is still poorly understood. During the course of this doctoral thesis research project, we aim to use several biophysical techniques (EPR, Mössbauer spectroscopy, SAXS, DLS, CD, among others) to characterise the structure-function properties of three metalloproteins: the human mitochondrial ferritin as well as a Dps mini-ferritin and a pair of copper storage proteins from a radioresistant bacteria.