Synthesis and Concomitant Assembly of Adeno-Associated Virus-like Particles in Escherichia coli

Le DT, Radukic M, Teschner K, Becker L, Müller K. Synthesis and Concomitant Assembly of Adeno-Associated Virus-like Particles in Escherichia coli . ACS Synthetic Biology . 2022.Virus-like particles (VLPs) have been used for numerous pharmaceutical applications, particularly vaccination and drug delivery. Recombinant adeno-associated virus (rAAV), a leading candidate in gene therapy, has been proposed as a vaccine scaffold, but high production costs limit its use. Here we establish intracellular production of AAV VLPs in Escherichia coli. VP3 capsid proteins of AAV serotype 5 (AAV5) were expressed, and VLPs were readily purified. The correct assembly was confirmed by ELISA with an intact-capsid AAV5 antibody and an AAVR domain as well as by atomic force microscopy. Biological functionality was demonstrated with a HeLa cell internalization assay. Coexpression of the assembly-activating protein (AAP) of AAV5 in E. coli improved capsid yield. This work provides the first evidence that AAV VLPs form in E. coli, opening new opportunities for production and exploration of AAV VLPs for biomedical applications

In situ XPS study of methanol reforming on PdGa near-surface intermetallic phases

In situ X-ray photoelectron spectroscopy and low-energy ion scattering were used to study the preparation, (thermo)chemical and catalytic properties of 1:1 PdGa intermetallic near-surface phases. Deposition of several multilayers of Ga metal and subsequent annealing to 503-523 K led to the formation of a multi-layered 1:1 PdGa near-surface state without desorption of excess Ga to the gas phase. In general, the composition of the PdGa model system is much more variable than that of its PdZn counterpart, which results in gradual changes of the near-surface composition with increasing annealing or reaction temperature. In contrast to near-surface PdZn, in methanol steam reforming, no temperature region with pronounced CO2 selectivity was observed, which is due to the inability of purely intermetallic PdGa to efficiently activate water. This allows to pinpoint the water-activating role of the intermetallic/support interface and/or of the oxide support in the related supported PdxGa/Ga2O3 systems, which exhibit high CO2 selectivity in a broad temperature range. In contrast, corresponding experiments starting on the purely bimetallic model surface in oxidative methanol reforming yielded high CO2 selectivity already at low temperatures (similar to 460 K), which is due to efficient O-2 activation on PdGa. In situ detected partial and reversible oxidative Ga segregation on intermetallic PdGa is associated with total oxidation of intermediate C-1 oxygenates to CO2. (c) 2012 Elsevier Inc. All rights reserved

Feeding the city: food cycles and the production of urban space

Städte bilden Schnittpunkte in translokalen Güterflüssen und Versorgungssystemen. Insbesondere die Versorgung der Stadtbevölkerung mit Lebensmitteln ist – wie die Wasser- oder Energieversorgung – eine Grundvoraussetzung für das Funktionieren städtischer Lebensweisen. Sie prägt die Beziehungen von Städten zu ihrem Hinterland. In der Geschichte bildete die ständige Expansion der Landwirtschaft und der Mittel des Warentransports eine wesentliche Bedingung für städtisches Wachstum, und heute hat die Lebensmittelversorgung längst eine planetarische Dimension angenommen. Ihre Formen und Abläufe, wie auch die Rituale des Essens, haben sich seit Jahrhunderten in die Architektur der Städte eingeschrieben. Dennoch bleiben die Strukturen der Lebensmittelversorgung meist unter dem Radar der Stadtforschung und -planung. Im Seminar „Feeding the City“ haben wir uns mit den Lieferketten konventioneller Lebensmittel befasst, wie wir sie im Supermarkt oder Discounter in großer Zahl und zu niedrigen Preisen kaufen können: abgepacktes Fabrikbrot, H-Milch, Hähnchenbrust, Bananen oder Fruchtgummis. Wo kommen sie her, welchen Weg nehmen sie und wie formen sie die Räume, durch die sie zirkulieren? Welche Akteur*innen und Regularien bestimmen diese Vorgänge und Zusammenhänge? Studierende der Stadtplanung und Architektur der BTU Cottbus-Senftenberg haben zehn alltägliche Lebensmittel verfolgt: Vom Ort ihres Anbaus oder der Tierhaltung über die Stationen der Lebensmittelindustrie und Distribution bis hin zum Einzelhandel, dem privaten Kühlschrank oder Esstisch und zur Entsorgung der Überbleibsel. Anhand von Kartierungen und Netzwerkdiagrammen haben sie die räumliche Reichweite und die Komplexität der Lieferketten betrachtet, sie haben die gebauten Räume einzelner Stationen und ihre städtischen Kontexte analysiert und schließlich nach der aktuellen oder historischen Präsenz des jeweiligen Produkts in der Stadt Cottbus gefragt.Cities form intersections in translocal flows of goods and supply systems. Food supply shapes the relationships between cities and their hinterlands and is a basic prerequisite for the functioning of urban lifestyles. Throughout history, urban growth has been accompanied by the constant expansion of agriculture and transportation networks. By now, these expansive dynamics of food supply systems have reached planetary dimensions. Food supply and processing, as well as eating rituals have been inscribed in the architecture of cities for centuries. Yet, these complex supply systems have largely remained under the radar of urban planning and urban research. In the seminar "Feeding the City", we explored the supply chains of conventional food items, which are commonly found in large numbers and at low prices in supermarkets, such as packaged and sliced bread, UHT milk, chicken breast, bananas or fruit gums. We followed ten products and looked at the places where they are produced and processed, the routes they take, and how they shape the spaces through which they circulate. We also zoomed in on the actors, regulations and power relations that determine these processes and contexts. Students of urban planning and architecture at the BTU Cottbus-Senftenberg have set out on a (mostly virtual) journey to trace everyday foodstuffs from the places where they are grown or raised, to the supermarkets in Cottbus, Germany. Using various mapping methods and network diagrams, they have developed a set of maps that illustrate the wide reach of supply chains around the world, complex actor-networks within food systems, the architectures of particular stations as well as their urban context, and the current or historical presence of the respective products in the city of Cottbus