Amin-substituierte Spiroacetale von Grundmanns Keton als neuartige Inhibitoren der humanen ∆8,7-Sterolisomerase

Die Cholesterolbiosynthese ist ein wichtiger Ansatzpunkt für die Kontrolle und Manipulation von biochemischen Vorgängen in Wirbeltieren und damit für die Entwicklung therapeutischer Wirkstoffe. Mit der Cholesterolbiosynthese assoziierte Krankheiten sind beispielsweise Hypercholesterinämie, die Alzheimer Erkrankung oder die Creutzfeld-Jakob Krankheit. Im Rahmen dieser Arbeit konnten ausgehend von Grundmanns Keton und alpha-Tetralon verschiedene Amin-substituierte Spiroacetale dargestellt werden, von denen mehrere Strukturen als spezifische Inhibitoren der humanen delta8,7-Sterolisomerase identifiziert werden konnten.Cholesterol biosynthesis is a major target for the controlling and manipulation of biochemical processes in mammals, and thus essential for the development of therapeutic drugs. Diseases associated with a malfunctioning cholesterol biosynthesis include hypercholesteremia, Alzheimer- and Creutzfeld-Jacob disease, to name but a few. Within the scope of this thesis, new amine-substituted spiroacetals from Grundmanns Keton and alpha-Tetralone were developed. Additionally, several compounds could be identified as specific inhibitors of human delta8,7-Sterolisomerase

(Video)Film in Africa and its relevance for development

Die vorliegende Arbeit befasst sich mit dem Medium Film als Sprachrohr der Gesellschaft. Es werden positive sowie negative Aspekte von Film und das Filmemachen selbst am Beispiel der nigerianischen Film- und Videoproduktionsindustrie diskutiert. Ziel dieser Abschlussarbeit ist es mit Hilfe den von mir durchgeführten Interviews mit nigerianischen Filmemacher_innen und –kritiker_innen und einer Filmanalyse der Frage, warum wird Film in Nigeria verwendet um Herausforderungen und Probleme der Gesellschaft aufzugreifen und auf welche Art und Weise wird dies umgesetzt, auf den Grund zu gehen. Seit den frühen 1980er Jahren zählen Videoproduktionen zu den wichtigsten Ausdruckformen von populärer Kunst und Kultur des westafrikanischen Landes. Austausch von Meinungen der Zivilgesellschaft, Bewusstseinsbildung und Kritik üben sind besondere Elemente von populärer Kultur, welche auch Entertainment-Education Konzepte weitgehend in ihrer Strategie aufgenommen haben. Entertainment-Education Produktionen bedienen sich einer Bandbreite von Medienformaten wie Radio, Musik, Fernsehen, Printmedien und Film, um gleichzeitig unterhaltend und bildend sein zu können. Die Idee hinter diesen Projekten ist dem Publikum zu zeigen, wie ein gesünderes, sichereres und glücklicheres Leben geführt werden kann, indem Themen wie Gesundheit, Bürger_innenrechte, Bildungssysteme, und ähnliches aufgegriffen werden. Der hier analysierte Film Arugbá, des bekannten nigerianischen Regisseurs Tunde Kelani, ist eine solche Entertainment-Education Produktion, welche sich zum Hauptziel gemacht hat, die nigerianische Gesellschaft hinsichtlich HIV/AIDS aufzuklären und zu sensibilisieren. Weiters werden verschiedene sozialkritische Themen wie Korruption, Bildung, Arbeitslosigkeit, usw., in einem nigerianischen Setting, wo die Diskussion um Tradition und Moderne eine wichtige Rolle spielt, aufgegriffen. Ebenfalls hat die Regierung von Lagos State Beiträge zu Umweltfragen, dem Steuersystem und Grundstückserwerb, welche vor allem die Bewohner_innen von Lagos als Zielgruppe haben, geleistet. Diese wurden weitgehend in die Narration des Filmes miteinbezogen. Der Film wurde mittels Mobile Cinema den Einwohner_innen von Lagos State zugänglich gemacht. Anhand von Fragebögen, die nach dem Screening ausgeteilt wurden, wurde Raum für Diskussionen, Anregungen und Kritiken gegeben und eröffnet. Dieser Schritt kann als wichtige Brücke zwischen Regierung und Zivilbevölkerung gesehen werden. Von nigerianischen Filmkritiker_innen wird weitgehend die Meinung vertreten, dass Filme einen wichtigen Beitrag für Bildung leisten können, indem eine Vielzahl von Menschen erreicht wird. Eine Unterstützung dafür ist auch, dass viele Filme neben Englisch in verschiedenen Sprachen, wie beispielsweise Yoruba, Hausa und Igbo, produziert werden. Film ist zu einem Instrument für Bewegungen der nigerianischen Gesellschaft geworden, welche informierend, allgemein- und bewusstseinsbildend sind. Für den Erfolg ist es wichtig, dass sich die Zielgruppen mit den Themen selbst identifizieren können.This thesis focuses on film as a message for the people. The Nigerian video and film production is used as a case study to discuss the positive and negative aspects of the medium. With the help of interviews with Nigerian film-makers and critics and through a film analysis, this study examines why the medium of film is used to reflect the challenges of society in Nigeria and how it can be implemented. Since the early 1980s, video productions have been an important expression of contemporary Nigerian popular art and culture. The exchange of meaning, public awareness and social and political critiques are special elements of popular culture. Entertainment-education productions use such ideas in their concepts, which are implemented in media formats such as radio, music, television, print media and film, to both educate and entertain their target groups. The general idea of such projects is to show the audience how they can live a healthier, safer and happier life, with illustrating themes such as the health system, civil rights, the education system etc. In this study, the film Arugbá by the famous Nigerian director Tunde Kelani is analysed. It is an entertainment-education production. The major aim of this movie is to raise awareness of HIV/AIDS in the West African country. Furthermore, different themes such as corruption, education, unemployment and so on are discussed in this film, which shows a Nigerian setting where the discussion of modernity and tradition plays an important role. Various messages from Lagos State Government concerning environmental sanitation, tax payment and land fraud were also inserted into the film. Here especially, the inhabitants of Lagos State were the target group. The film Arugbá was screened via mobile cinema in all the local governments and local council development areas of Lagos State. After the screening, a short questionnaire was given to gather information on enjoyment, government messages and what was gained from the film. The audience was also encouraged to comment on governmental issues and room for criticism was provided. The co-operation with Lagos State Government could be seen as a bridge between the government and the society. Nigerian film critics advance the view that the medium of film is important for spreading education as it reaches the masses. A large proportion of the population has the opportunity to watch and understand the films, as apart from in English, they are also rendered in languages such as Yoruba, Hausa and Igbo. Film became a tool for the Nigerian society to inform, educate and to make the civil population aware of current social and political challenges and the problems of the country. For the success of a film, it is important that target groups can identify themselves with the subject matter

Crystal structure of DegP from Escherichia coli

DegP is a heat-shock protein which is localized in the periplasm of Escherichia coli. It is a common protein quality control factor and represents the only protein that can alternate between the two antagonistic activities of a protease and a chaperone in a temperature-dependent manner. In this study the crystal structure of the hexameric form of DegPs2ioA from Escherichia coli was solved at 2.8A resolution by multiple anomalous dispersion phasing. As the protein was crystallized at room temperature, this structure represents the chaperone conformation. Each DegP monomer is built up by a trypsin-like serine protease domain and two consecutive PDZ domains. The hexamer is a dimer of trimers with crystallographic D3 symmetry. Oligomerization is mediated by the protease domains and results in the formation of an internal cavity where the active sites are located. Access towards the internal cavity is controlled by the flexible PDZ domains. The protease activity is absent because access towards the active sites is blocked by the interaction of several surface loops. Furthermore, the active site geometry is distorted. The crystal structure of the wild-type DegP confirmed that the inactive conformation is not due to the artificial serine to alanine mutation of the DegPs2ioA structure but represents an inherent feature of the chaperone state to avoid unwanted proteolysis at room temperature. The crystal structure of DegP in complex with the covalent serine protease inhibitor diisopropyl fluorophosphate could not preserve the protease conformation. Analysis of degradation products by mass spectrometry revealed that the product length varies between 6 and 25 amino acid residues with a clear preference for small hydrophobic residues in the PI position. Furthermore, time-dependent analyses of degradation products by high-performance liquid chromatography showed that DegP degrades its substrates in a processive fashion, similar to other cage-forming proteases

Amin-substituierte Spiroacetale von Grundmanns Keton als neuartige Inhibitoren der humanen ∆8,7-Sterolisomerase

Die Cholesterolbiosynthese ist ein wichtiger Ansatzpunkt für die Kontrolle und Manipulation von biochemischen Vorgängen in Wirbeltieren und damit für die Entwicklung therapeutischer Wirkstoffe. Mit der Cholesterolbiosynthese assoziierte Krankheiten sind beispielsweise Hypercholesterinämie, die Alzheimer Erkrankung oder die Creutzfeld-Jakob Krankheit. Im Rahmen dieser Arbeit konnten ausgehend von Grundmanns Keton und alpha-Tetralon verschiedene Amin-substituierte Spiroacetale dargestellt werden, von denen mehrere Strukturen als spezifische Inhibitoren der humanen delta8,7-Sterolisomerase identifiziert werden konnten.Cholesterol biosynthesis is a major target for the controlling and manipulation of biochemical processes in mammals, and thus essential for the development of therapeutic drugs. Diseases associated with a malfunctioning cholesterol biosynthesis include hypercholesteremia, Alzheimer- and Creutzfeld-Jacob disease, to name but a few. Within the scope of this thesis, new amine-substituted spiroacetals from Grundmanns Keton and alpha-Tetralone were developed. Additionally, several compounds could be identified as specific inhibitors of human delta8,7-Sterolisomerase

epsilon-regime of dilaton chiral perturbation theory

The $\epsilon$-regime of dilaton chiral perturbation theory is introduced. We compute the dilaton mass, the chiral condensate and the topological susceptibility in the $\epsilon$-regime, as a function of the fermion mass. The microscopic spectral density of the Dirac operator is obtained from dilaton chiral perturbation theory. Our main result is that the chiral condensate and the spectral density are related to their counterparts from ordinary chiral perturbation theory via a simple scaling relation. This relation originates from the mass dependence of the dilaton potential, and is valid in both the $\epsilon$-regime and the $p$-regime. In the $\epsilon$-regime, moreover, all results agree with the universal predictions to leading order in $\epsilon$.Comment: 25 pages, 2 table

Factors Defining the Functional Oligomeric State of Escherichia coli DegP Protease

Escherichia coli DegP protein is a periplasmic protein that functions both as a protease and as a chaperone. In the absence of substrate, DegP oligomerizes as a hexameric cage but in its presence DegP reorganizes into 12 and 24-mer cages with large chambers that house the substrate for degradation or refolding. Here, we studied the factors that determine the oligomeric state adopted by DegP in the presence of substrate. Using size exclusion chromatography and electron microscopy, we found that the size of the substrate molecule is the main factor conditioning the oligomeric state adopted by the enzyme. Other factors such as temperature, a major regulatory factor of the activity of this enzyme, did not influence the oligomeric state adopted by DegP. In addition, we observed that substrate concentration exerted an effect only when large substrates (full-length proteins) were used. However, small substrate molecules (peptides) always triggered the same oligomeric state regardless of their concentration. These results clarify important aspects of the regulation of the oligomeric state of DegP

Are Diffusion Models Vision-And-Language Reasoners?

Text-conditioned image generation models have recently shown immense qualitative success using denoising diffusion processes. However, unlike discriminative vision-and-language models, it is a non-trivial task to subject these diffusion-based generative models to automatic fine-grained quantitative evaluation of high-level phenomena such as compositionality. Towards this goal, we perform two innovations. First, we transform diffusion-based models (in our case, Stable Diffusion) for any image-text matching (ITM) task using a novel method called DiffusionITM. Second, we introduce the Generative-Discriminative Evaluation Benchmark (GDBench) benchmark with 7 complex vision-and-language tasks, bias evaluation and detailed analysis. We find that Stable Diffusion + DiffusionITM is competitive on many tasks and outperforms CLIP on compositional tasks like like CLEVR and Winoground. We further boost its compositional performance with a transfer setup by fine-tuning on MS-COCO while retaining generative capabilities. We also measure the stereotypical bias in diffusion models, and find that Stable Diffusion 2.1 is, for the most part, less biased than Stable Diffusion 1.5. Overall, our results point in an exciting direction bringing discriminative and generative model evaluation closer. We will release code and benchmark setup soon.Comment: Accepted to NeurIPS 202

Recombinant Deg/HtrA proteases from Synechocystis sp. PCC 6803 differ in substrate specificity, biochemical characteristics and mechanism

Cyanobacteria require efficient protein-quality-control mechanisms to survive under dynamic, often stressful, environmental conditions. It was reported that three serine proteases, HtrA (high temperature requirement A), HhoA (HtrA homologue A) and HhoB (HtrA homologue B), are important for survival of Synechocystis sp. PCC 6803 under high light and temperature stresses and might have redundant physiological functions. In the present paper, we show that all three proteases can degrade unfolded model substrates, but differ with respect to cleavage sites, temperature and pH optima. For recombinant HhoA, and to a lesser extent for HtrA, we observed an interesting shift in the pH optimum from slightly acidic to alkaline in the presence of Mg2+ and Ca2+ ions. All three proteases formed different homo-oligomeric complexes with and without substrate, implying mechanistic differences in comparison with each other and with the well-studied Escherichia coli orthologues DegP (degradation of periplasmic proteins P) and DegS. Deletion of the PDZ domain decreased, but did not abolish, the proteolytic activity of all three proteases, and prevented substrate-induced formation of complexes higher than trimers by HtrA and HhoA. In summary, biochemical characterization of HtrA, HhoA and HhoB lays the foundation for a better understanding of their overlapping, but not completely redundant, stress-resistance functions in Synechocystis sp. PCC 6803

Virtual Screening of Histone Lysine Demethylase(JMJD2) identifies new inhibitors

The JmjC domain-containing proteins are hydroxylases that confer posttranslational modifications on histone tails, by removing methylation marks on methylated lysine residues. This serves to either promote or repress gene transcription. The JMJD2A-D family members include the enzyme Jumonji domain 2C (JMJD2C), which specifically demethylates di- and trimethylated histone H3 at Lys 9 or Lys 36.[1] Dysregulation of JMJD2C has been implicated in prostate, colonic, and breast cancer as the demethylase can modify the expression levels of oncogenes.[2] The goal of the present study was to identify potent and selective small-molecule inhibitors of JMJD2C, to be used as chemical biology tools to further investigate the role of JMJD2C in cell proliferation and survival. Using high-resolution crystal structures of the JMJD2 subfamily members as templates, we have performed a small molecule virtual docking screen. From the ~3 million molecules that were docked, this experiment identified 21 compounds as possible leads. These compounds were tested against JMJD2C in enzymatic assays and here we report an overall hit rate of 76%, with 8 compounds demonstrating an IC50 of 176μM to 1.18μM. A molecule containing a salicylate core was selected as a candidate for optimization and thus far we have completed several rounds of iterative target-specific compound docking, hybrid molecule design, compound synthesis and in vitro characterization. Notably, our method demonstrated a substantial increase in potency when we linked two docked fragments together and further derivatized this new scaffold, through which we have successfully derived a 65nM inhibitor of JMJD2C. A compound representing the inhibitor scaffold has been co-crystallized with JMJD2A to a resolution of 2.4 Å. In the crystal structure each asymmetric unit contains two JMJD2A monomers, each bound to a single inhibitor molecule. This complex-structure superposes well with the docked pose for the hybrid series of compounds. We are now focusing our efforts on identifying an inhibitor that is selective for the JMJD2 family over other JmjC domain-containing proteins