Exploring molecular mechanisms of key targets in metabolic and infectious diseases

[eng] This doctoral thesis is focused on disclosing molecular factors that regulate the functional mechanism of key targets in i) metabolic disorders, such as diabetes and obesity, and ii) tuberculosis (TB). These diseases have a high impact on the public health, and TB is one of the diseases that causes highest mortality rates based on the World Health Organization reports. Accordingly, gaining insight on functionally relevant protein structures with key roles in these diseases and understanding their regulatory mechanisms can pave a way to identify novel therapeutic targets. Regarding the metabolic disorders, I have specifically studied the direct activation mechanism of adenosine-monophosphate activated protein kinase (AMPK) by different activators, such as A-769662, SC4 and PF-739, since AMPK plays an important role in cellular energy homeostasis and it is directly related to diabetes type 2 and obesity. These studies were carried out to explore the molecular basis of the selective isoform activation of AMPK, especially focusing on the role played by the two different isoforms of β subunit. The first part of this research was focused on the direct activation by A-769662 compound in α2β1 isoform, and the second part addressed the important issue of isoform selectivity, it being dedicated to examine the structural and dynamical properties of β1- and β2-containing AMPK complexes formed with A-769662, SC4 and PF-739. The results revealed the mechanical sensitivity of the α2β1 complex, in contrast with a larger resilience of the α2β2 species. Moreover, binding of activators to α2β1 promotes the pre-organization of the ATP-binding site, favoring the adoption of activated states of the enzyme. In another part of the research related to AMPK, in collaboration with Prof. Ana Castro from Institute of Medicinal Chemistry and Prof. María S. Fernández-Alonso from Complutense University of Madrid, I studied a novel indolic compound synthesized and experimentally analysed by their group as modulator of endothelial AMPK that acts as a mixed-type inhibitor. It means that this modulator, IND6, may bind the ATP-binding site leading to competitive inhibition of the enzyme but also suggest that IND6 may regulate the AMPK activity through binding to an additional pocket. Regarding TB, I have studied the truncated hemoglobin N (trHbN) of Mycobacterium tuberculosis (Mtb). These studies aimed to disclose innovative therapeutic approaches by identifying the molecular basis of t