The thesis specializes in the computational description of pharmaceutically important compounds. A substantial number of pharmaceutical drugs are small molecules that are bound to an active site of an enzyme by the "lock (binding site) and key (drug)" model through non-covalent interactions. The association of enzymes with drugs cause an increase or decrease in the activity of enzymes. The main topic is focused on the computational elucidation of the structural basis for the interactions of the purine-like compounds with the enzyme cyclin- dependent kinase 2 that belongs to the protein-kinase enzyme family. These enzymes play an important role in the cell cycle regulation; their increased activity significantly contributes to the loss of control over cell proliferation, which is one of the primary causes of cancer cell formation. The study describes the binding motifs of roscovitine, which shows an inhibitory effect on the function of cyclin-dependent kinases, and its analogues containing bioisosteric central heterocycles in the complex with cyclin-dependent kinase 2. The binding affinity between the cyclin-dependent kinase 2 enzyme and the inhibitors was quantified as calculated binding scores and evaluated in relation to the conformation of the optimized structures. The hybrid model combining the...

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The BioChemical Library (BCL) cheminformatics toolkit is an application-based academic open-source software package designed to integrate traditional small molecule cheminformatics tools with machine learning-based quantitative structure-activity/ property relationship (QSAR/QSPR) modeling. In this pedagogical article we provide a detailed introduction to core BCL cheminformatics functionality, showing how traditional tasks (e.g., computing chemical properties, estimating druglikeness) can be readily combined with machine learning. In addition, we have included multiple examples covering areas of advanced use, such as reaction-based library design. We anticipate that this manuscript will be a valuable resource for researchers in computer-aided drug discovery looking to integrate modular cheminformatics and machine learning tools into their pipelines.

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<p>Nonsteroidal anti-inflammatory drugs are among the most commonly used prescription and over-the-counter medications, but they often produce significant gastrointestinal ulceration and bleeding, particularly in elderly patients and patients with certain co-morbidities. Novel anti-inflammatory drugs are seldom tested in animal models that mimic the high-risk human users, leading to an underestimate of the true toxicity of these drugs. In the present study we examined the effects of two novel NSAIDs and two commonly used NSAIDs in models in which mucosal defence was expected to be impaired. Naproxen, celecoxib, ATB-346 (a hydrogen sulfide- and naproxen-releasing compound) and NCX 429 (a nitric oxide- and naproxen-releasing compound) were evaluated in healthy, arthritic, obese, hypertensive rats, and in rats of advanced age (19 months) and rats co-administered low-dose aspirin and/or omeprazole. In all models except hypertension, greater gastric and/or intestinal damage was observed when naproxen was administered in these models than in healthy rats. Celecoxib-induced damage was significantly increased when co-administered with low-dose aspirin and/or omeprazole. In contrast, ATB-346 and NCX 429, when tested at doses that were as effective as naproxen and celecoxib in reducing inflammation and inhibiting cyclooxygenase activity, did not produce significant gastric or intestinal damage in any of the models. These results demonstrate that animal models of human co-morbidities display the same increased susceptibility to NSAID-induced gastrointestinal damage as observed in humans. Moreover, two novel NSAIDs that release mediators of mucosal defence (hydrogen sulfide and nitric oxide) do not induce significant gastrointestinal damage in these models of impaired mucosal defence.</p> / Master of Science (MSc)

<p>Colorectal cancer leads to more than 600,000 deaths worldwide per year. An abundance of research has shown that several non-steroidal anti-inflammatory drugs (NSAIDs) can exert chemotherapeutic and chemo-preventative effects in colorectal cancer patients. It is important to note, that use of many different NSAIDs carries a significant risk for cardiovascular and gastrointestinal (GI) complications. A recently developed group of NSAIDs, which release hydrogen sulfide (H₂S), has been shown to have greatly reduced these side effects as compared to conventional NSAIDs. This is likely attributable to the ability of H₂S to increase the resistance of the GI mucosa to injury, as well as to accelerate repair of injury when it occurs. Moreover, H₂S has been shown to be a vasodilator, and therefore may offset some of the hypertensive effects of NSAIDs.</p> <p>We assessed the chemotherapeutic actions of two of these newly developed NSAIDs. ATB-346 is an H₂S-releasing derivative of naproxen and ATB-352 is an H₂S-releasing derivative of ketoprofen. These drugs were tested in the azoxymethane mouse model and in the APC^Min/+mouse model of Colorectal cancer.</p> <p>In the azoxymethane model of colorectal cancer ATB-346 caused a significant reduction in number aberrant crypt foci (ACF), which are pre-neoplastic lesions used as markers of colorectal cancer. The reduction was superior to naproxen at all doses tested. ATB-352 also caused a significant reduction in the number of ACF, however the reduction was not superior to that produced by ketoprofen. In APC^Min/+mice treated with ATB-346 for 14 days (14.5 mg/kg) we observed a complete inhibition of the formation of colonic polyps/tumours and a 97.5% reduction in total polyp score. Shorter treatment with ATB-346 also produced similar reduction in total polyp score. We found that ATB-346-treated mice had lower levels of b-catenin and cmyc without significant changes in APC or p53 levels. <strong></strong></p> <p>These results demonstrate ATB-346 can exert superior chemo-preventative effects in mice models of colon cancer while leading to no gastric or intestinal damage.</p> / Master of Science (MSc)

[ES] La cristalografía de rayos X es una potente técnica para la resolución de la estructura atómica de macromoléculas. La información generada, tiene gran impacto sobre diferentes campos relacionados con la investigación básica y aplicada, como son la biomedicina y diseño de fármacos, al igual que en el desarrollo de aplicaciones nanotecnológicas y biotecnológicas. Esta Tesis se centra en determinadas problemáticas actuales y en las proteínas involucradas en las mismas (TryR, eEF1A2 y CBDP35), siendo éstas sujeto de desarrollo biotecnológico en los campos de la biomedicina, farmacia y de la industria alimentaria, en el que la cristalografía de rayos X juega un papel crucial para dilucidar sus estructuras atómicas y funciones. En consideración a la biomedicina y diseño de fármacos, hemos resuelto la estructura de la Tripanotión reductasa (TryR) de Leishmania infantum en complejo con potentes inhibidores de su actividad oxidorreductasa, con potencial de desarrollo como fármacos. Así, se ha caracterizado la unión y mecanismo de acción de éstos inhibidores. TryR es una reconocida diana farmacológica para el tratamiento de la enfermedad de Chagas, la Tripanosomiasis Humana Africana y la leishmaniosis, ya que desempeña un papel crucial y esencial en el metabolismo redox de los parásitos de la familia Trypanosomatidae. Además, se han analizado los parámetros de cristalización y difracción de novedosos inhibidores de la dimerización de TryR, cuyo diseño racional se basa en la unión a la interfaz de dimerización de la misma. La oncoproteína eEF1A2, involucrada en múltiples funciones celulares y sujeto de numerosas modificaciones post-traduccionales, se une al fármaco anticancerígeno plitidepsina. La cristalografía de rayos X, combinada con experimentos de espectrometría de masas, se han utilizado como herramientas para identificar nuevas modificaciones post-traduccionales y características estructurales en eEF1A2:GDP. Una modificación única, la adición de etanolamina fosfoglicerol (EPG) a aminoácidos conservados (Glu301 y Glu374 en mamíferos), se ha observado aquí por primera vez. El análisis estructural de estos hallazgos facilita la comprensión de las múltiples funciones y regulaciones de eEF1A2. La adquisición de una muestra conformacionalmente homogénea de eEF1A2:GTP, necesaria para la unión a la plitidepsina, ha sido evaluada en ensayos de cristalización del complejo terciario de eEF1A2: GTP: plitidepsina. Con respecto al dominio de unión a la pared celular de la endolisina PlyP35 codificada por el fago P35 de Listeria monocytogenes (CBDP35), hemos resuelto la estructura cristalina de CBDP35 en un complejo con ácido teicoico natural de L. monocytogenes serovar 1/2a. Esta estructura es el primer módulo de unión a la pared celular en complejo con ácidos teicoicos jamás dilucidado. El análisis estructural reveló los principales determinantes para la unión de la pared celular bacteriana, en particular, el mecanismo molecular del reconocimiento de N-acetil-d-glucosamina, una decoración de carácter glicosídico en ácidos teicoicos de serovares patógenos de L. monocytogenes. Estos hallazgos arrojan luz sobre el desarrollo biotecnológico de nuevas herramientas en la industria alimentaria y las terapias derivadas de fagos para detectar y tratar infecciones bacterianas. / [CA] La cristal·lografia de raig X és una potent tècnica per a la resolució de l'estructura atòmica de macromolècules. La informació generada té gran impacte sobre diferents camps relacionats amb la investigació bàsica i aplicada, com són la biomedicina i disseny de fàrmacs, igual que en el desenvolupament d'aplicacions nanotecnológiques i biotecnològiques. Aquesta Tesi es centra en determinades problemàtiques actuals i en les proteïnes involucrades en les mateixes (TryR, eEF1A2 i CBDP35), sent estes subjecte de desenvolupament biotecnològic en els camps de la biomedicina, farmàcia i de la indústria alimentària, en el que la cristal·lografia de raig X juga un paper crucial per a dilucidar les seues estructures atòmiques i funcions. En consideració a la biomedicina i disseny de fàrmacs, hem resolt l'estructura de la Tripanotión reductasa (TryR) de Leishmania infantum en complex amb potents inhibidors de la seua activitat oxidorreductasa, amb potencial de desenrotllament com a fàrmacs. Així, s'ha caracteritzat la unió i mecanisme d'acció d'estos inhibidors. TryR és una reconeguda diana farmacològica per al tractament de la malaltia de Chagas, la Tripanosomiasi Humana Africana i la leishmaniosi, ja que exerceix un paper crucial i essencial en el metabolisme redox dels paràsits de la família Trypanosomatidae. A més, s'han analitzat els paràmetres de cristal·lització i difracció de nous inhibidors de la dimerizació de TryR, el disseny racional dels quals es basa en la unió a la interfície de dimerización de la mateixa. L'oncoproteína eEF1A2, involucrada en múltiples funcions cel·lulars i subjecte de nombroses modificacions posttraduccionals, s'unieix al fàrmac anticancerigen plitidepsina. La cristal·lografia de raig X, combinada amb experiments d'espectrometria de masses, s'han utilitzat com a ferramentes per a identificar noves modificacions posttraduccionals i característiques estructurals en eEF1A2:GDP. Una modificació única, l'addició d'etanolamina fosfoglicerol (EPG) a aminoàcids conservats (Glu301 i Glu374 en mamífers), s'ha observat ací per primera vegada. L'anàlisi estructural d'estes troballes facilita la comprensió de les múltiples funcions i regulacions d'eEF1A2. L'adquisició d'una mostra conformacionalmente homogènia d'eEF1A2:GTP, necessària per a la unió a la plitidepsina, ha sigut avaluada en assajos de cristal·lització del complex terciari d'eEF1A2: GTP: plitidepsina. Respecte al domini d'unió a la paret cel·lular de l'endolisina PlyP35 codificada pel fago P35 de Listeria monocytogenes (CBDP35), hem resolt l'estructura cristal·lina de CBDP35 en un complex amb àcid teicoico natural de L. monocytogenes serovar 1/2a. Esta estructura és el primer mòdul d'unió a la paret cel·lular en complex amb àcids teicoicos mai dilucidat. L'anàlisi estructural va revelar els principals determinants per a la unió de la paret cel·lular bacteriana, en particular, el mecanisme molecular del reconeixement de N-acetil-d-glucosamina, una decoració de caràcter glicosídico en àcids teicoicos de serovares patògens de L. monocytogenes. Estes troballes fan llum sobre el desenrotllament biotecnològic de noves ferramentes en la indústria alimentària i les teràpies derivades de fagos per a detectar i tractar infeccions bacterianes. / [EN] X-ray crystallography is a powerful technique for atomic structure resolution of macromolecules. The information generated impacts different fields involving basic and applied research on biomedicine and drug design and the development of nanotechnology and biotechnological applications. This dissertation focuses on current problematics and the target proteins involved (TryR, eEF1A2 and CBDP35) that are in sight for biotechnological development in the biomedical, pharmaceutical and food industry fields, in which X-ray crystallography plays a crucial role in the elucidation of their atomic structures and functions. Attaining to biomedical and drug design problematics, we have solved the structure of Leishmania infantum TryR in complex with potent oxidoreductase inhibitors prone to further development as anti-trypanosomal drugs, thereby characterizing their binding and mechanism of action. This protein is a long recognized drug target for the treatment of Chagas disease, Human African Trypanosomiasis and leishmaniasis, as it plays a crucial and essential role in the redox-metabolism of the Trypanosomatidae parasites. Moreover, the crystallization and diffraction parameters of novel TryR dimerization disruptors have been assayed for inhibitors which have been rationally designed to bind the dimerization interface of TryR. The "moonlighting" oncoprotein eEF1A2 is known to be highly post-translationally modified and to bind the anticancer drug plitidepsin. X-ray crystallography, combined with mass-spectrometry experiments, have been used as tools to identify novel post-translational modifications and structural features in eEF1A2:GDP. A unique modification, namely the addition of ethanolamine phosphoglycerol (EPG) to conserved glutamic residues (Glu301 and Glu374 in mammals), has been here observed for the first time. Structural analysis of these findings facilitate the understanding of eEF1A2's multiple functions and regulations. The acquirement of a conformationally homogenous eEF1A2:GTP sample, necessary for plitidepsin binding, has been has been assayed for eEF1A2:GTP:plitidepsin complex crystallization. Regarding the cell wall binding domain of Listeria monocytogenes phage-encoded endolysin PlyP35 (CBDP35), we have solved the crystal structure of CBDP35 in complex with natural Listeria serovar 1/2a teichoic acid. This structure is the first cell wall binding module in complex with teichoic acids ever elucidated. Structural analysis revealed the main determinants for bacterial cell-wall binding, in particular, the molecular mechanism of N-acetyl-d-glucosamine recognition, a glycosidic moiety in teichoic acids of pathogenic serovars of L. monocytogenes. These findings shed light upon the biotechnological development of new tools in the food industry and phage-derived therapies to detect and treat bacterial infections. / Agradecer al Ministerio de Educación, Cultura y Deporte por haberme proporcionado el contrato FPU (FPU14/03190) que me ha permitido desarrollar esta Tesis Doctoral en el Instituto de Química-Física “Rocasolano” del Consejo Superior de Investigaciones Científicas (IQFR-CSIC), así como la financiación otorgada para poder realizar mi estancia predoctoral en el laboratorio del Prof. Hammershmidt, en Greifswald, Alemania (EST17/00751). / Carriles Linares, AÁ. (2019). STRUCTURAL BIOMEDICINE: CHARACTERIZATION OF THE STRUCTURAL BASIS IN PROTEIN-DRUG RECOGNITION IN DIFFERENT HUMAN DISEASES [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/130844

Les protéines à domaines PDZ sont impliquées dans des interactions protéine-protéine (IPP) et participent aux transports de signaux impliqués dans de nombreuses pathologies (cancer, mucoviscidose, douleur,…). L’interruption de l’interaction entre la protéine à domaine PDZ, PSD-95, et le récepteur de la sérotonine, 5-HT2A, réduit l’hyperalgie mécanique sur un modèle expérimental de douleur neuropathique chez les rats. Afin de concevoir de nouveaux inhibiteurs de cette interaction, antalgiques potentiels, trois stratégies ont été développées au cours de ces travaux. Une première stratégie a consisté à réaliser une étude de relation structure-activité à partir d’un inhibiteur connu, qui nous a permis d’identifier des groupements pharmacophores et ainsi obtenir une nouvelle molécule possédant un noyau indolique, capable d’inhiber l’interaction entre PSD-95 et 5-HT2A et possédant un effet anti-hyperalgique chez le rat neuropathique. La deuxième stratégie a consisté à valider la méthode du fragment-based drug design aux protéines à domaines PDZ en réalisant la déconstruction d’un inhibiteur connu de l’interaction en plusieurs fragments qui ont été criblés par RMN HSQC 1H-15N. Une évaluation systématique par RMN de chaque couple de fragments, suivie d’une étude de modélisation moléculaire a ensuite permis de mettre en évidence trois nouvelles molécules qui ont été synthétisées et évaluées par RMN HSQC 1H-15N. La troisième stratégie a été une approche peptidomimétique à partir de l’extrémité C-terminale de 5-HT2A, qui a conduit à la synthèse d’un peptoïde capable d’interagir avec la protéine à domaine PDZ. Ces études nous permettent d’envisager le développement de nouveaux antalgiques soit issus de la synthèse organique soit issus de mimes de peptides. / PDZ domains proteins are involved in protein-protein interaction (PPI) and participate in the transport of signals involved in numerous diseases (cancer, cystic fibrosis, pain, …). The disruption the interaction between the PDZ domains protein, PSD-95, and the serotonin receptor, 5-HT2A, reduces mechanical hyperalgesia in a rodent model of neuropathic pain in rats. To design new inhibitors as potential analgesics of this interaction, three strategies have been developed in this work. A first strategy was to conduct a study of structure-activity relationship from a known inhibitor, which allowed us to identify the pharmacophore groups and obtain a new molecule with an indole ring, capable of inhibiting the interaction between PSD-95 and 5-HT2A and possessing an anti-hyperalgesic effect on neuropathic rats. The second strategy was to validate the method of fragment-based drug design with PDZ domains proteins by deconstruction of a known inhibitor of the interaction in several fragments which were screened by NMR HSQC 1H-15N. Systematic evaluation by NMR of each pair of fragments, followed by molecular modeling study was then used to highlight three new molecules that were synthesized, and evaluated by NMR HSQC 1H-15N. The third strategy was a peptidomimetic approach from the C-terminal of 5-HT2A receptors, which led to the synthesis of a peptoid able to interact with the PDZ domain protein. These studies allow us to consider the development of new analgesics either from organic synthesis or from peptide mimetics.