A Cytochrome b561 with Ferric Reductase Activity from the Parasitic Blood Fluke, Schistosoma japonicum

Parasites acquire their food from their hosts, either by feeding directly on tissues of the host, or by competing for ingested food. Adult schistosomes live within the vasculature of humans and rely on the blood cells and plasma they ingest and dissolved solutes they derive across their body surface, the tegument, for their nutrition. Schistosomes require host trace elements, notably iron, which is used as a co-factor in many biological reactions. Iron is especially important for schistosomes, for it has a significant role in egg formation and embryogenesis. In human tissues, iron predominates in the trivalent (ferric) form; however, it is the divalent (ferrous) form that is used as an essential co-factor for multiple biomolecules and enzymes. In order to be acquired from the host environment, the valency of iron must be modified to render it suitable for transport across the parasite membrane. This paper describes the molecular characterisation of a schistosome molecule that is crucial for bringing about this change in iron. Schistosoma japonicum Cytb561 is the first ferric reductase characterised in any parasitic helminth and emphasises the importance of iron, and other divalent cations, in these organisms

New Perspectives on the Use of Phytochemicals as an Emergent Strategy to Control Bacterial Infections Including Biofilms

The majority of current infectious diseases are almost untreatable by conventional antibiotic therapy given the advent of multidrug-resistant bacteria. The degree of severity and the persistence of infections are worsened when microorganisms form biofilms. Therefore, efforts are being applied to develop new drugs not as vulnerable as the current ones to bacterial resistance mechanisms, and also able to target bacteria in biofilms. Natural products, especially those obtained from plants, have proven to be outstanding compounds with unique properties, making them perfect candidates for these much-needed therapeutics. This review presents the current knowledge on the potentialities of plant products as antibiotic adjuvants to restore the therapeutic activity of drugs. Further, the difficulties associated with the use of the existing antibiotics in the treatment of biofilm-related infections are described. To counteract the biofilm resistance problems, innovative strategies are suggested based on literature data. Among the proposed strategies, the use of phytochemicals to inhibit or eradicate biofilms is highlighted. An overview on the use of phytochemicals to interfere with bacterial quorum sensing (QS) signaling pathways and underlying phenotypes is provided. The use of phytochemicals as chelating agents and efflux pump inhibitors is also reviewed

International Conference on Biological and Medical Sciences ICBMS 2023

Welcome to the International Conference on Biological and Medical Sciences (ICBMS 2023). As the chair of this event, it's a privilege to have you join us virtually from across the globe. Today, we gather to explore the forefront of biological and medical research, connecting minds and sharing ideas that will shape the future of healthcare and scientific progress. I want to extend a special thank you to our collaborator, the University College of Conventional Medicine, Faculty of Medicine and Allied Health Sciences, Islamia University of Bahawalpur, for their invaluable support in making this conference possible. ICBMS 2023 is a platform for the exchange of knowledge and innovation among researchers, scholars, and experts. Let's make the most of this opportunity to learn, engage, and collaborate. I also express my gratitude to the World Forum for Young Scientists (WFYS) for their dedication to fostering scientific dialogue. To our speakers, presenters, and participants, thank you for your contributions and dedication to advancing science. Let's make ICBMS 2023 an enriching experience for all. Thank you for being a part of this journey. With utmost appreciation,   Dr. Kamala Badalova (Chair, ICBMS 2023) Assistant Professor Azerbaijan Medical University, Azerbaijan &nbsp

Probing Cancer Targets and Therapeutic Mechanisms using Small Molecules

Small molecules are a powerful tool to illuminate biological mechanisms and assist in the identification and validation of therapeutic targets. KRAS is the single most frequently mutated oncogene in human cancer, with particularly high mutation frequencies observed in pancreas (95%), colon (45%), and lung (35%) cancer. However, despite three decades of effort, there is no clinical viable KRAS cancer therapy. The first part of this thesis focuses on exploring the potential of directly targeting the KRAS nucleotide binding site. Directly targeting oncogenic KRAS with small molecules in the nucleotide-binding site has had limited success due to the high affinity of KRAS for nucleotide GTP and the high cellular concentration of GTP. The strategy of generating engineered KRAS allele based on shape and covalent complementarity was exploited herein to address this challenge. Using fragment-based small molecule design, a cell-membrane-permeable covalent inhibitor able to irreversibly modify the engineered nucleotide-binding site of KRAS was developed. The second part of this thesis describes the investigation of the therapeutic potential of imidazole ketone erastin (IKE), a small molecule inhibitor of the cystine/glutamate antiporter system xc–, in a subcutaneous xenograft model of Diffuse Large B Cell Lymphoma (DLBCL). A biodegradable polyethylene glycol-poly(lactic-co-glycolic acid) nanoparticle formulation was employed to aid in the delivery of IKE to cancer cells in vivo. This IKE nanoparticle system showed improved tumor accumulation and therapeutic index relative to free IKE, indicating its potential for treating DLBCL. The final part of this thesis describes the study of lipid metabolism features of ferroptotic cell death using quantitative reverse transcription PCR (RT-qPCR) and mass spectrometry-based lipidomic analysis. In summary, this work illustrates how chemistry and chemical biology approaches can supplement existing efforts towards the design and discovery of new drugs for challenging targets, as well as aid in the study of therapeutic mechanisms

Synthetic biology tools for environmental protection

Synthetic biology transforms the way we perceive biological systems. Emerging technologies in this field affect many disciplines of science and engineering. Traditionally, synthetic biology approaches were commonly aimed at developing cost-effective microbial cell factories to produce chemicals from renewable sources. Based on this, the immediate beneficial impact of synthetic biology on the environment came from reducing our oil dependency. However, synthetic biology is starting to play a more direct role in environmental protection. Toxic chemicals released by industries and agriculture endanger the environment, disrupting ecosystem balance and biodiversity loss. This review highlights synthetic biology approaches that can help environmental protection by providing remediation systems capable of sensing and responding to specific pollutants. Remediation strategies based on genetically engineered microbes and plants are discussed. Further, an overview of computational approaches that facilitate the design and application of synthetic biology tools in environmental protection is presented

Genome Mining and Synthetic Biology in Marine Natural Products Discovery

In recent years, marine genomics has become a growning rapidly field, helped by the large amount of information that is becoming available to the international scientific community. Taking into account the current excitement in the field of marine biotechnology, this Special Issue entitled “Genome Mining and Synthetic Biology in Marine Natural Product Discovery” aims to to assess the impact of these molecular approaches on the discovery of bioactive compounds from marine organisms. The term “genome mining” is used to identify all bioinformatic investigations aimed at detecting the biosynthetic pathways of bioactive natural products and their possible functional and chemical interactions. Several studies are now reporting on marine organisms. Oceans cover nearly 70% of the Earth’s surface and host a huge ecological, chemical, and biological diversity. The natural conditions of the sea favor, in marine organisms, the production of a large variety of novel molecules with great pharmaceutical potential. Marine organisms are unique in their structural and functional features compared to terrestrial ones. Innovation in this field is very rapid, as revealed by the funding of several Seventh Framework Programme (FP7) and Horizon 2020 projects under the topic “Blue Growth”, with the urgent goal of discovering new drugs

Exploiting gene regulation as an approach to identify, analyze and utilize the biosynthetic pathways of the glycopeptide ristomycin A and the zincophore [S,S]-EDDS in Amycolatopsis japonicum

The microbial secondary metabolism is a rich source for valuable products that have found their way into various clinical and industrial applications. A particularly productive bacterial genus for the discovery of natural products is Amycolatopsis. The most frequently reported type of secondary metabolites produced by this genus, are glycopeptide antibiotics like balhimycin or the medically relevant vancomycin. In contrast to most other members of the Amycolatopsis genus, Amycolatopsis japonicum was never described to produce any product with antibacterial activity. This strain however is known to synthesize the chelating agent ethylenediamine-disuccinate ([S,S]-EDDS), a biodegradable EDTA isomer in response to zinc deficiency. This zinc responsive repression of [S,S]-EDDS production indicates that it contributes to zinc uptake and that it belongs to the rarely described physiological group of the zincophores. Combining excellent chelating properties with the accessibility to biodegradation, [S,S]-EDDS is considered as a sustainable chelating agent, possessing the potential to replace EDTA and other environmentally threatening chelating agents in various applications. In this study, two distinct molecular genetic strategies were developed and implemented to activate the biosynthesis of the glycopeptide antibiotic ristomycin A or to identify the [S,S]-EDDS biosynthetic genes in Amycolatopsis japonicum, respectively. Genetic evaluation of the Amycolatopsis antibiotic biosynthetic potential indicated that A. japonicum might has the capability to produce a glycopeptide antibiotic. Since the biosynthesis of the predicted glycopeptide was not inducible by variations in culture conditions, a molecular genetic approach was employed to activate its production. Heterologous expression of the characterized pathway specific activator Bbr, naturally inducing the balhimycin biosynthesis in A. balhimycina, also induced the synthesis of a bioactive substance by A. japonicum. The bioactivity could be assigned to the production of ristomycin A, a highly glycosylated peptide antibiotic which is used as compound in diagnostic kits to detect widespread hereditary coagulation disorders. Full sequencing of the A. japonicum genome and its computational analysis led to the identification of the corresponding biosynthetic gene cluster which is directing the biosynthesis of ristomycin A. Such computational genome analyses by various bioinformatic tools are nowadays standardized applied strategies to identify secondary metabolite gene clusters. These approaches however failed in the identification of the [S,S]-EDDS biosynthetic genes. This required the development of a new approach which relies on the assumption that the zinc repressed biosynthesis of [S,S]-EDDS is regulated by a zinc responsive regulatory element. Therefore, the major zinc responsive transcriptional regulator of A. japonicum (Zur) was characterized in detail. Zur regulates the expression of the high affinity zinc uptake system ZnuABC by binding to a specific DNA binding sequence. The screening of the A. japonicum genome for further Zur regulated genes by using this deduced Zur binding sequence led to the identification of the operon aesA-D. Extensive transcriptional analyses and band shift assays revealed that aesA-D is zinc responsively regulated by Zur and involved in [S,S]-EDDS biosynthesis, as shown by inactivation studies. The [S,S]-EDDS biosynthesis was uncoupled from zinc repression by deleting zur. This mutant sets the stage to establish a sustainable [S,S]-EDDS production process without limits formerly imposed by zinc repression. The strategy to awake predicted silent gene clusters by using a characterized regulator as well as the strategy to identify new biosynthetic genes by characterizing an environmental signal-sensing regulator enabled the isolation of novel biosynthetic pathways in A. japonicum. Both approaches follow the joint concept to exploit knowledge of regulatory pathways and have the prospect to be generally applicable in order to guide future detection of new natural products.Der mikrobielle Sekundärmetabolismus ist eine reichhaltige Quelle für Naturstoffe, von denen viele klinische beziehungsweise industrielle Anwendung gefunden haben. Die Gattung Amycolatopsis ist für die Synthese vieler Naturstoffe bekannt. Beispielsweise werden viele Glykopeptid-Antibiotika, wie das klinisch relevante Vancomycin oder das Balhimycin, von Stämmen dieser Gattung produziert. Im Gegensatz dazu wurde der Stamm Amycolatopsis japonicum nie als Produzent einer biologisch aktiven Substanz beschrieben. Dieser Stamm produziert jedoch unter Zinkmangelbedingungen das EDTA-Isomer Ethylendiamindisuccinat ([S,S]-EDDS). Diese zinkabhängige [S,S]-EDDS Produktion lässt darauf schließen, dass [S,S]-EDDS ein Zinkophor ist, das an der Zinkaufnahme beteiligt ist. [S,S]-EDDS weist Komplexbildungseigenschaften auf, die mit denen von EDTA vergleichbar sind. Im Gegensatz zu EDTA ist [S,S]-EDDS jedoch biologisch abbaubar. Die weite industrielle Anwendung von EDTA in Kombination mit dessen Unzugänglichkeit für biologische Abbauprozesse führt zu einer umweltgefährdenden EDTA-Persistenz in aquatischen Lebensräumen. Der Naturstoff [S,S]-EDDS ist deshalb ein nachhaltiger EDTA Ersatz mit einem verbesserten ökologischen Fingerabdruck. In dieser Arbeit wurden zwei molekulargenetische Strategien entwickelt, um die Biosynthese des Glykopeptid-Antibiotikums Ristomycin A zu aktivieren und um die [S,S]-EDDS-Biosynthese-Gene in A. japonicum zu identifizieren. Untersuchungen des genetischen Potenzials der Gattung Amycolatopsis ließen vermuten, dass auch A. japonicum die Fähigkeit besitzt, ein Glykopeptid-Antibiotikum zu synthetisieren. Um dieses nicht exprimierte, sogenannte „stille Gencluster“ zu aktivieren, wurde ein molekulargenetischer Ansatz verwendet, bei dem der Biosynthese-spezifische Aktivator Bbr heterolog in A. japonicum exprimiert wurde. Bbr reguliert die Balhimycin-Biosynthese in Amycolatopsis balhimycina. In A. japonicum induzierte dessen Expression die Produktion von Ristomycin A, was durch HPLC-DAD, MS, MS/MS, HR-MS, und NMR-Analysen bestätigt werden konnte. Ristomycn A ist ein vielfach glykosyliertes Heptapeptid, das als Hauptwirkstoff in Diagnoseverfahren zur Bestimmung von angeborenen und weitverbreiteten Blutgerinnungsstörungen verwendet wird. Die Sequenzierung des A. japonicum Genoms und dessen computergestützte Auswertung führten zur Identifizierung des Biosynthese-Genclusters, das für die Synthese von Ristomycin A verantwortlich ist. Solche computergestützten Genomanalysen mittels verschiedenster bioinformatischen Plattformen werden heutzutage standardmäßig zur Identifizierung von Sekundärmetabolit-Gencluster angewandt, die bekannten Synthesemechanismen zugeordnet werden können. Allerdings konnten die [S,S]-EDDS-Biosynthese-Gene mit diesen Tools nicht entdeckt werden, was auf einen bislang nicht bekannten Biosynthesemechanismus hindeutet. Um diesen zu identifizieren, wurde ein neuer Ansatz entwickelt, der auf der Annahme beruht, dass die Zink-reprimierte [S,S]-EDDS-Biosynthese durch einen Zink-sensitiven Regulator gewährleistet wird. Die bakterielle Zink-Homöostase wird meistens durch den globalen Zink-spezifische Transkriptionsregulator Zur reguliert. Das Zur Protein von A. japonicum wurde identifiziert und detailliert charakterisiert. Es konnten gezeigt werden, dass ZurAj die Transkription des hoch affinen Zinkaufnahmesystems ZnuABCAj durch seine Zink-abhängige Bindung an spezifische DNA Bindesequenzen reguliert. Diese Zur-Bindesequenzen wurden verwendet, um das A. japonicum Genom nach weiteren, ZurAj regulierten, Genen zu durchsuchen. Dies führte zur Auffindung des aesA-D Operons. Umfangreiche Transkriptions-Untersuchungen ergaben, dass aesA-D Zink-abhängig von ZurAj reguliert wird. Die Beteiligung von aesA-D an der [S,S]-EDDS konnte durch Inaktivierungsversuche nachgewiesen werden. Zusätzlich führte die Deletion des Zinkregulators ZurAj (A. japonicum Δzur) dazu, dass auch in Gegenwart von hohen Zink-Konzentrationen [S,S]-EDDS in hohen Mengen produziert wird. A. japonicum Δzur ist eine erfolgversprechende Ausgangsbasis, um einen nachhaltigen und wirtschaftlich verwertbaren [S,S]-EDDS Produktionsprozess zu entwickeln, der keiner Limitierung durch negative Einflüsse von Zink unterliegt. Die Strategie, ein vorhergesagtes, stilles Gencluster durch die Expression eines spezifischen Regulators zu aktivieren, sowie auch die Strategie, neue Biosynthese-Gene durch die Charakterisierung eines globalen Regulators, der spezifische Umweltsignale wahrnimmt, zu identifizieren, ermöglichte die Charakterisierung neuer Naturstoffsynthesewege in A. japonicum. Beide Ansätze nutzen Erkenntnisse über regulatorische Mechanismen und besitzen das Potenzial zukünftig angewendet zu werden, um neue Naturstoffe und neue Synthesewege zu identifizieren