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Description of Potential Energy Surfaces of Molecules using FFLUX Machine Learning ModelsHughes, Zak, Thacker, J.C.R., Wilson, A.L., Popelier, P.L.A. 12 March 2018 (has links)
Yes / A new type of model, FFLUX, to describe the interaction between atoms has been
developed as an alternative to traditional force fields. FFLUX models are constructed from applying
the kriging machine learning method to the topological energy partitioning method, Interacting
Quantum Atoms (IQA). The effect of varying parameters in the construction of the FFLUX models is
analyzed, with the most dominant effects found to be the structure of the molecule and the number of
conformations used to build the model. Using these models the optimization of a variety of small
organic molecules is performed, with sub kJ mol-1 accuracy in the energy of the optimized molecules.
The FFLUX models are also evaluated in terms of their performance in describing the potential energy
surfaces (PESs) associated with specific degrees of freedoms within molecules. While the accurate
description of PESs presents greater challenges than individual minima, FFLUX models are able to
achieve errors of <2.5 kJ mol-1 across the full C-C-C-C dihedral PES of n-butane, indicating the future
possibilities of the technique.
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<b>Sterile Manufacturing of Drug Products and Their Applications to Bacteriophages</b>Aaron J Gin (20385423) 17 December 2024 (has links)
<p dir="ltr">Sterile manufacturing is multifaceted. Each aspect seeks to improve the process of producing drug products absent of impurities. Bacteriophages can benefit greatly from sterile manufacturing which would amplify their already vast range of applications. Novel bacteriophage discovery and annotation, implemented within a classroom setting, can aid in building the foundation of bacteriophages for use in clinical applications. High-Performance Liquid Chromatography (HPLC) can detect impurities and test compatibilities in the final product. Oxytocin and its interaction with tranexamic acid (TXA) provide an excellent example of how HPLC use can be critical in sterile manufacturing as well as build a baseline for which bacteriophages may be utilized in sterile production. A quality scorecard for drug products provides an additional metric that can be used by governing agencies and consumers to analyze drug products of similar bioequivalence and subsequently grade them. The development of a scorecard will provide a guideline to improve the sterile manufacturing of drug products and biologics such as bacteriophages. A literary analysis of lipid nanoparticles presents a future application for synthetically manufactured bacteriophages. The conclusions gathered from this work can be utilized as a case study for working professionals who aim to implement advancements in sterile manufacturing within their industry.</p>
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Effect of transforming growth factor-β on up/down regulation of integrin-β1 in primary chondrocyte cultureKhaghani, Seyed A., Sefat, Farshid, Youseffi, Mansour, Rehman, R., Soon, Chin Fhong, Akbarova, G. January 2016 (has links)
yes / Regeneration of a damaged or non-functioning tissue requires adhesion of cells to their extracellular matrix (ECM). Thus the investigation of the level of synthesised cell adhesion molecules (CAMs) in cell culture systems play major roles in cell and tissue engineering. Adhesion of chondrocyte to a collagen type-II rich matrix, is dependent on cell adhesion molecules (CAMs) and integrins and cells adhere to ECM through integrins.
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<b>LIMK2-UBE2C SYNERGY DRIVES CASTRATION-RESISTANT PROSTATE CANCER AND CDK5-CYCLIN B1 REGULATES MITOTIC PROGRESSION AND FIDELITY</b>Humphrey L Lotana (17770503) 26 April 2024 (has links)
<p dir="ltr">UBE2C is upregulated in castration-resistant prostate cancer and shows strong correlation with high tumor grade. Currently, the scarcity of UBE2C inhibitors is alarming. This study is the first to report UBE2C post-translational modulation mediated by LIMK2 kinase. A proteome-wide screen previously conducted in the Shah lab has identified UBE2C as a direct substrate of LIMK2 using an innovative chemical genetic approach. LIMK2 regulates UBE2C in a variety of ways. First, LIMK2 directly associates with UBE2C in cells. Second, LIMK2 phosphorylates UBE2C at S123 and increases its stability at the protein level. Third, LIMK2 upregulates UBE2C mRNA and protein expression levels in cells. Contrary to its well-established function as an enzyme involved in the ubiquitin-proteosome pathway, UBE2C stabilizes LIMK2 protein expression in a reciprocal loop. This study is the first to show UBE2C stabilizing its substrate. Likewise, UBE2C increases LIMK2 mRNA and protein levels; however, the mechanism is to be elucidated. LIMK2-UBE2C loop is extremely oncogenic creating CRPC pathogenesis <i>in vivo</i>. Targeting LIMK2 is a suitable approach to effectively degrade both UBE2C and LIMK2 which leads to significant inhibition of tumor formation, cancer stem cell phenotype and epithelial to mesenchymal transition <i>in vivo</i>. Additionally, CDK1 for the longest time was thought to be the only protein of the cyclin dependent kinase family which binds to and is activated by cyclin B1 to regulate cell cycle progression. We first showed CDK5 activity in cell division and its importance in maintaining mitotic fidelity. We first established the activation of CDK5 by cyclin B1 <i>in vitro</i>. The phospho-mimetic CDK5 was observed to be less active when bound to cyclin B1 than its wild-type counterpart.</p>
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SYNTHESIS AND EVALUATION OF POTENT INHIBITORS OF DISEASE-DRIVING KINASES VIA ONE-FLASK DOEBNER-POVAROV REACTIONAllison Lea Kempen (18360270) 15 April 2024 (has links)
<p dir="ltr">Cancer is the second leading cause of death worldwide, and there is a continued need for effective treatments to combat the disease. A key challenge in cancer therapy persists in the form of therapeutic resistance. While kinase inhibitors (KIs) have shown promise in treating cancer patients with dysregulated protein kinases, treatment failures are common, highlighting the urgent need to address this issue. Despite the approval of 80 protein kinase inhibitors by the United States Food and Drug Administration (FDA), and numerous others in clinical trials, the chemical space explored for protein kinase inhibitors remains limited. Most FDA-approved kinase inhibitors share common core moieties, such as indazole, quinoline, pyrazole, and pyrimidine, indicating a lack of diversification in drug development in this area.</p><p dir="ltr">Efforts to expand the chemical space have led to the identification of a novel 3<i>H</i>-pyrazolo-[4,3-<i>f</i>]quinoline core by the Sintim group. This scaffold can be efficiently synthesized through the Doebner–Povarov multicomponent reaction using readily available ketones, heteroaromatic aldehydes, and 5-aminoindazole. This multicomponent chemistry affords small molecules which inhibit disease-associated protein kinases with sub-nanomolar IC<sub>50</sub> values. Additionally, the scaffold presents a unique opportunity to tune for selectivity via judicious substitution patterns, allowing us to target numerous disease-driving kinases, such as FLT3, haspin, and CLK, with the use of simple multi-component chemistry.</p><p dir="ltr">From this work emerged lead amide-containing compound HSK205, which potently inhibits FLT3 and haspin and shows impressive potencies against FLT3-driven acute myeloid leukemia cell lines, with GI<sub>50</sub> values between 2 and 20 nM. Western blot analyses indicate that HSK205 inhibits the phosphorylation of FLT3 and histone H3 (substrate of haspin) in Molm-14 AML cells. Further exploration led to the discovery of lead CLK inhibitors, such as HSK1132 and HSK3110, which inhibit the growth of multiple myeloma cell lines <i>in vitro</i> with GI<sub>50</sub> values as low as 17 nM. Additionally, these compounds are orally bioavailable and reduce the growth of multiple myeloma RPMI-8226 xenograft model in mice by 69%.</p>
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<b>Development of Chemical Probes to Study Protein Guanosine Monophosphorylation</b>Sara Sedky Elshaboury (19200796) 25 July 2024 (has links)
<p dir="ltr">Post-translational modifications (PTMs) play a crucial role in regulating protein function and location. Protein AMPylation, the addition of adenosine monophosphate (AMP), significantly influences protein trafficking, stability, and pathogenic virulence. The Fic Domain family of proteins targets hydroxyl-containing amino acid residues (Ser, Thr, or Tyr), catalyzing the addition of various phosphate-containing moieties such as nucleoside monophosphates (NMPs), phosphocholine, and phosphate. Using gene mining techniques, Dr. Seema Mattoo’s group has identified a clade of Fic domain containing proteins typified by the enzyme originating from <i>Bordetella bronchiseptica</i> (BbFic) which prefers utilizing guanosine triphosphate (GTP) as a substrate over other nucleotides. To understand the physiological role of GMPylation, identifying the proteins modified by BbFic is a first critical step and can be accomplished via mass spectrometry-based proteomics. For a low stoichiometry PTM like GMPylation, however, there is a need to develop chemical tools that enable the targeted enrichment of modified protein. Identifying key interactions between substrate proteins and the BbFic nucleotide binding site will enable development of highly specific molecular tags for Fic substrates.</p><p dir="ltr">The goal of this research project, therefore, is to design chemical probes to tag Fic enzyme substrates, thereby facilitating the identification of GMPylated proteins in chemical proteomics workflows. A set of ATP and GTP analogues carrying either alkyne or azide handles were proposed as possible probes. While 8-azido guanosine showed a high docking score in our in-silico study, literature reports highlight its chemical instability upon exposure to air and light. An alternative probe, the 8-ethynyl guanosine, also showed a high docking score and docks in the same position and orientation as guanosine (the natural ligand) but necessitates synthetically challenging via cross-coupling reactions.</p><p dir="ltr">We considered multiple GMP analogues as potential molecular tags with the assistance of molecular docking with the BbFic enzyme. With predicted binding affinities in hand, we prioritized candidate GTP analogs for synthesis to probe the BbFic-mediated protein GMPylation process. While N6 propargyl guanosine serves as a lead probe for AMPylation, computational analysis reveals challenges with O6 due to its altered hydrogen bond donor/acceptor presentation. The distinctive chemical properties of guanosine, compared to adenosine, require a thorough evaluation of protective group strategies, as not all synthetic methodologies used for ATP analogue synthesis are applicable to GTP analogues. Isolating the triphosphate analogue proved challenging, although purification of the monophosphorylated counterpart is feasible. The Protide analogue benefits from phosphate charge masking, which facilitates purification. While much work remains until the physiological role of GMPylation can be determined, important progress has been made in the design and synthesis of chemical tools for studying this newly discovered PTM.</p>
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Reaching the Bose-Einstein Condensation of Dipolar Molecules: a Journey from Ultracold Atoms to Molecular Quantum ControlBigagli, Niccolò January 2024 (has links)
Achieving the quantum control of ever more complex systems has been a driving force of atomic, molecular, and optical physics. This goal has materialized in the harnessing of systems with increasingly rich structures and interactions: the more sophisticated the system, the more faceted and fascinating its application to fields as varied as quantum simulation, quantum information, many body physics, metrology, and quantum chemistry. One of the current frontiers of quantum control is ultracold dipolar molecules. They present rich internal structures and long-range, anisotropic dipole-dipole interactions which promise to revolutionize AMO physics, for example by realizing realistic Hamiltonians in quantum simulation, by providing a new platform for quantum information, and by achieving a novel kind of quantum liquid.
Despite its promises, the full quantum control of dipolar molecules has been over a decade in the making. The difficulties in either directly laser cooling molecules or in collisionally stabilizing their bulk samples have been major roadblocks that have hampered the development of this quantum system. The realization of a Bose-Einstein condensate of dipolar molecules has been a particularly elusive milestone. In this thesis, I report on the first observation of this quantum state of matter.
The work that brought us to this achievement parallels the historical evolution of AMO physics in the last thirty years. To reach a BEC of molecules, we initially constructed a dual species experiment capable of realizing the simultaneous Bose-Einstein condensation of atomic sodium (Na) and cesium (Cs). Individual BECs of sodium and cesium were first reported in 1995 and 2003 respectively, while our experiment was the first instance of their concurrent condensation. The study of the Na-Cs interatomic scattering properties in an homogeneous magnetic field showed us the path to the Feshbach association of loosely-bound sodium-cesium (NaCs) molecules, a technique first demonstrated in 2006 for heteronuclear molecules but never attempted on our species. Following the Feschbach association, we determined a novel pathway to the molecular electronic, vibrational and rotational ground state using STIRAP.
From this point, we found ourselves at the forefront of the field: bulk samples of bosonic molecules such as NaCs had neither been stabilized against collisional losses nor evaporatively cooled. At first, we successfully applied a single-frequency microwave shielding approach to decrease in-bulk losses by a factor of 200 and reach lifetimes on the order of 2 s, allowing us to measure high elastic scattering rates and characterize their dipolar anisotropy. Moreover, we demonstrated the first evaporative cooling of a bosonic molecular gas by increasing its phase-spacedensity by a factor of 20 and reaching a temperature of 36(5) nK. Since this proved insufficient to achieve Bose-Einstein condensation due to unexpected three-body losses, we introduced an enhanced microwave shielding technique, double microwave shielding. This further decreased loss rates enabling efficient evaporative cooling of our sample to a long-lived Bose-Einstein condensate of dipolar molecules. This new double microwave shielding technique also allows the tunability of the strength of dipole-dipole interaction, establishing ultracold bosonic dipolar molecules as a new quantum liquid for the exploration of many body physics.
In addition to the experimental work on dipolar NaCs, we have theoretically explored the field of direct molecular laser cooling. Our aim was twofold: we aimed to expand the category of molecules that can be laser cooled and to simplify the identification of laser cycling schemes. For the former goal, we lifted the widespread assumption that only molecules with diagonal Franck-Condon factors could be laser cooled. For the latter, we decided to employ publicly available repositories of molecular transitions. A second consequence of the use of these databases is that they contain data on molecules of interest to other scientific fields, further establishing direct laser cooling as a technique that could be of interest beyond AMO physics. Our work was successful in that we identified laser cycling schemes for C₂ and OH+. To simplify the determination of laser cycling schemes, we developed a graph-based algorithm form their identification starting from spectroscopic data.
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Molecular modeling and computer-aided design of potential protease inhibitorsCalvino, Toni T. 01 January 1999 (has links)
No description available.
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Osmium atoms and Os2 molecules move faster on selenium-doped compared to sulfur-doped boronic graphenic surfacesBarry, Nicolas P.E., Pitto-Barry, Anaïs, Tran, J., Spencer, S.E.F., Johansen, A.M., Sanchez, A.M., Dove, A.P., O'Reilly, R.K., Deeth, R.J., Beanland, R., Sadler, P.J. 06 July 2015 (has links)
Yes / We deposited Os atoms on S- and Se-doped boronic graphenic surfaces by electron bombardment of micelles containing 16e complexes [Os(p-cymene)(1,2-dicarba-closo-dodecarborane-1,2-diselenate/dithiolate)] encapsulated in a triblock copolymer. The surfaces were characterized by energy-dispersive X-ray (EDX) analysis and electron energy loss spectroscopy of energy filtered TEM (EFTEM). Os atoms moved ca. 26× faster on the B/Se surface compared to the B/S surface (233 ± 34 pm·s–1 versus 8.9 ± 1.9 pm·s–1). Os atoms formed dimers with an average Os–Os distance of 0.284 ± 0.077 nm on the B/Se surface and 0.243 ± 0.059 nm on B/S, close to that in metallic Os. The Os2 molecules moved 0.83× and 0.65× more slowly than single Os atoms on B/S and B/Se surfaces, respectively, and again markedly faster (ca. 20×) on the B/Se surface (151 ± 45 pm·s–1 versus 7.4 ± 2.8 pm·s–1). Os atom motion did not follow Brownian motion and appears to involve anchoring sites, probably S and Se atoms. The ability to control the atomic motion of metal atoms and molecules on surfaces has potential for exploitation in nanodevices of the future. / We thank the Leverhulme Trust (Early Career Fellowship No. ECF-2013 414 to NPEB), the University of Warwick (Grant No. RDF 2013-14 to NPEB), the EPSRC (EP/G004897/1 to RKOR), and ERC (Grant No. 247450 to PJS) for support.
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Identification and characterization of small molecules inhibiting the RNA binding protein HuRBonomo, Isabelle 24 October 2019 (has links)
Post-transcriptional control of gene expression in Eukaryotes plays a pivotal role in determining intricated networks defining physiological and pathological conditions among each organism. RNA Binding Proteins (RBPs), by exploiting RNA-protein and protein-protein interactions, have been recognized as the main actors in modulating these processes. As a consequence, RBPs aberrant expression, modulation or mis-localization, leads to the insurgence of complex phenotypes and diseases. Therefore, targeting and modulating the activity of RBPs found associated to different pathologies represents a new promising therapeutic strategy. During my PhD I aimed at identify, characterize and refine inhibitors targeting the RNA binding protein HuR. HuR belongs to the ELAVL protein family, it is ubiquitously expressed in the cells and among tissues and highly conserved throughout mammalian evolution. By binding AU/U rich elements (ARE) in the 3’UTRs of mRNAs, HuR mainly stabilizes its target transcripts, enhancing their translation. ARE sequences are found in 7% of the human mRNAs, coding for protein involved in key cellular processes as: immune response and inflammation, cell division and proliferation, angiogenesis, senescence and apoptosis. Hence, dysregulation in HuR expression and in its subcellular localization have been associated with the insurgence of several pathologies, mostly cancers and inflammation diseases. Notably, malignant transformations and poor prognosis in patients have been found characterized by highly nuclear or cytosolic HuR expression in a significant number of human cancers. Indeed, the majority of HuR regulated transcripts encode for protein responsible for the appearance of several cancerogenic traits. In particular, critical crosstalk established between cancer cells and inflammation processes play a pivotal role in worsening and compromising cancers development and onset. Moreover, considering that 90% of mRNAs coding for cytokines and chemokines contains repeated AREs sites in the 3’UTR, HuR plays a strong regulatory role in immune system (innate and adaptive) development and homeostasis as well as in pathogenic mechanisms. The searching for HuR inhibitors represents a challenging area, in the drug discovery field, due to its pleiotropic functions and its intrinsic structural complexity, which presents unfolded regions and sequences prone to aggregation. HuR disruptors have been reported in the literature, but without systematic studies, thus the identification of a new class of small molecules is still at the beginning. Among the molecules discovered so far, in 2015 our group identified through a High-throughput Screening a natural compound, DHTS, as a bona fide HuR inhibitor. Following that finding, we, me included, ascribed to the molecule a well-defined mechanism of action, identifying the specific binding sites on which HuR:DHTS interaction is based, defining that upon the mRNA binding DHTS interplays with HuR maintaining the protein in a closed conformation, thus inhibiting its function. Furthermore, we demonstrated DHTS anti-cancer activity in vitro, in cellular context and in vivo, in an HuR-dependent manner. In this way, DHTS represented the molecular scaffold, for the generation of a new class of highly potent HuR inhibitors, called Tanshinone Mimics (TMs). A functional oriented approach was applied for the synthesis of new molecules harboring only DHTS chemical elements responsible for HuR targeting, leading to a completely new molecular scaffold, not previously described in the literature, with respect to the ancestor molecule. I have characterized and identified more potent molecules, describing their anticancer properties, through the evaluation of their capabilities of downregulating the total expression level of well-known HuR targets, coding for proteins involved in tumor insurgence and progression, as VEGF, ERBB2 and CTNNB1, and reducing cancer cell migration, cell cycle progression in a minor extent. On the other end, I have explored TMs anti-inflammatory properties, counteracting the inflammatory response mediated by macrophages, directly impairing the binding between HuR and its pro-inflammatory targets, diminishing their expression and related protein secretion. Moreover, I have put evidences on TMs activity in vivo in acute inflammation mouse models. Lastly, I have evaluated TMs activity in affecting T-cells proliferation, on which HuR it is known to play a regulatory role. In conclusion, we identified TMs with Structure-Activity Relationships (SARs) towards HuR inhibition and its biological implications, aimed at ameliorating their specificity and bioavailability suitable for in vivo therapeutic strategies.
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