Identification of new molecular targets and design of new drugs for the treatment of infections caused by fungi, using a new strategy based on human "pharmacoloma"

N this project we propose to develop and implement a new strategy to identify new therapeutic targets in fungi, which in turn allows us to design specific drugs against these new targets. the reduced repertoire of antifungal drugs currently available, and the limitations they present, make it necessary to develop new drugs, more effective and safer, to combat these infections that represent an emerging threat to human health. with this objective, it is important to identify new molecular targets in the fungus, and also ensure that new drugs developed against these targets specifically attack the fungus without causing adverse effects. significant in the human host. the limited development of medications for fungal infections contrasts with the impetuous development of drugs for other diseases, targeting a variety of molecular targets in humans. according to a recent and comprehensive review published in nature reviews [santos et al, 2017], the u.s. food and drug administration has approved the use of 1,578 drugs that act on 893 different biomolecular targets, mostly of human nature, and others from different pathogens. this set of targets on which approved drugs act is defined in the article as the "pharmacolome." commonly, the identification of new targets in pathogens focuses on unique proteins, not present in humans, or that if they have homologous human proteins (orthologs), which at least the similarity in sequence between them is low. in our project, however, we intend to use a diametrically opposite approach: identify orthologous fungal proteins, and with similar active sites (but not identical!), to human pharmacoloma proteins, which opens a mine of opportunities for the large amount of proteins that make up the pharmacolome. these fungal proteins must meet two important requirements to become potential therapeutic targets: 1) be proteins with important metabolic functions in the cell, that is, essential for the vitality of the fungus; and 2) the active sites of the human protein and its fungus ortholog, although they are very conserved, they must have a few amino acid differences in such a way that they produce specific changes in the topology and / or chemical properties of the fungus's active site. these changes would offer a “design space” to create new specific inhibitors for fungal targets. on the other hand, the high structural similarity between orthologous proteins makes it possible to validate fungal targets using cross-reactivity human protein inhibitors. our proposal has as a precedent a project currently underway by our team, in which we are obtaining very encouraging results using the enzyme phosphatidylinositol-3-kinase (pi3k) as a therapeutic target in histoplasma capsulatum. in humans, this enzyme is currently a target for cancer treatment, and dozens of inhibitors have been developed against it. we have also carried out a preliminary investigation with a set of proteins from pharmacoloma, whose results are very stimulating and give solid support to our working hypothesis. in particular, we have identified two orthologous proteins in histoplasma capsulatum and fusarium oxysporum, which meet the necessary requirements to be investigated as potential therapeutic targets in these fungi, and will serve as a point of heading in our project. the main expected results in the project are the following: demonstration of the viability of our new strategy for the search for new therapeutic targets in microorganisms, based on the identification of orthologs of human pharmacoloma proteins with topological and chemical differences at the site of binding of inhibitors. identification of new therapeutic targets in fungi, with possible application in the design of new drugs to combat these infections. new inhibitors of vital proteins for fungi, specific for these proteins. publication of 4 scientific articles in journals with category a1, and 4 presentations in congresses, at least 2 of them in international congresses. training of a phd student of the modeling and computing program scientist from the university of medellín, and linking a second student. it is important to highlight that, although in this project we will use two species of fungi in particular (histoplasma capsulatum and fusarium oxysporum) as case studies to implement our strategy, our project has a greater scope. taking into account the high similarity between the genomic sequences of different species of pathogenic fungi, and the equivalence of orthologous proteins in terms of functionality and possible relevance to the vitality of microorganisms, it is predictable that the new therapeutic targets that we identify and validate in h. capsulatum and f. oxysporum, as well as the new inhibitors that we intend to design, can be used in the treatment of infections caused by other species of pathogenic fungi. even more important, the designed strategy is applicable not only in fungi, but also in other pathogens.

Identify and validate new therapeutic targets in pathogenic fungi histoplasma capsulatum and fusarium oxysporum, and design new inhibitors of these specific targets for these mushrooms. specific objectives identify orthologs of human pharmacoloma proteins in histoplasma capsulatum and fusarium oxysporum, and select a set of 6-10 proteins between both fungi, which will pass to an intensive phase of computational evaluation for the selection of potential inhibitors. identify, based on predictions of binding affinity obtained from high-performance computational simulations, a set of up to 50 potential inhibitors of the selected histoplasma capsulatum and fusarium oxysporum proteins, which will be evaluated experimentally. to evaluate in vitro, in strains of histoplasma capsulatum and fusarium oxysporum, the ability of the selected molecules to inhibit the growth of these fungi, as a method of chemical validation of potential therapeutic targets and, at the same time, to select a set of inhibitors that will serve as leading compounds in the subsequent design of specific drugs. design and identify in databases, and evaluate in vitro new specific inhibitors for the new fungal targets identified

Articles category 4, 4 presentations, 1 phd student; 1 linking phd student, in doctorado de modelación y computación científica de la u. de medellín.