Development of electrically powered DNA origami nanomachines requires effective means to actuate moving origami parts by externally applied electric fields. We demonstrate how origami nanolevers on ...an electrode can be manipulated (switched) at high frequency by alternating voltages. Orientation switching is long-time stable and can be induced by applying low voltages of 200 mV. The mechanical response time of a 100 nm long origami lever to an applied voltage step is less than 100 μs, allowing dynamic control of the induced motion. Moreover, through voltage assisted capture, origamis can be immobilized from folding solution without purification, even in the presence of excess staple strands. The results establish a way for interfacing and controlling DNA origamis with standard electronics, and enable their use as moving parts in electro-mechanical nanodevices.
The receptor tyrosine kinase HER2 acts as oncogenic driver in numerous cancers. Usually, the gene is amplified, resulting in receptor overexpression, massively increased signaling and unchecked ...proliferation. However, tumors become frequently addicted to oncogenes and hence are druggable by targeted interventions. Here, we design an anti-HER2 biparatopic and tetravalent IgG fusion with a multimodal mechanism of action. The molecule first induces HER2 clustering into inactive complexes, evidenced by reduced mobility of surface HER2. However, in contrast to our earlier binders based on DARPins, clusters of HER2 are thereafter robustly internalized and quantitatively degraded. This multimodal mechanism of action is found only in few of the tetravalent constructs investigated, which must target specific epitopes on HER2 in a defined geometric arrangement. The inhibitory effect of our antibody as single agent surpasses the combination of trastuzumab and pertuzumab as well as its parental mAbs in vitro and it is effective in a xenograft model.
Dynamic methods of biosensing based on electrical actuation of surface-tethered nanolevers require the use of levers whose movement in ionic liquids is well controllable and stable. In particular, ...mechanical integrity of the nanolevers in a wide range of ionic strengths will enable to meet the chemical conditions of a large variety of applications where the specific binding of biomolecular analytes is analyzed. Herein, we study the electrically induced switching behavior of different rodlike DNA origami nanolevers and compare to the actuation of simply double-stranded DNA nanolevers. Our measurements reveal a significantly stronger response of the DNA origami to switching of electrode potential, leading to a smaller potential change necessary to actuate the origami and subsequently to a long-term stable movement. Dynamic measurements in buffer solutions with different Mg2+ contents show that the levers do not disintegrate even at very low ion concentrations and constant switching stress and thus provide stable actuation performance. The latter will pave the way for many new applications without largely restricting application-specific environments.
The use of length‐predefined DNA origami constructs acting as nanolevers in the analysis of protein binding kinetics requires an optimized and cost‐efficient nanolever assembly, and therefore, a ...customized scaffold strand synthesis. In this paper, a top‐down and a bottom‐up approach for the fabrication of two scaffold strands of customized length for predefined DNA origami structures are presented. Three different origami structures are synthesized and analyzed in terms of accuracy of shape, yield as well as the costs attributed to each fabrication route.
In this paper, a top‐down and a bottom‐up approach for the fabrication of two scaffold strands of customized length for predefined DNA origami structures are presented. Three different origami structures are synthesized and analyzed in terms of accuracy of shape, yield as well as the costs attributed to each fabrication route.
The CRISPR-Cas9 RNA-guided endonuclease system allows precise and efficient modification of complex genomes and is continuously developed to enhance specificity, alter targeting and add new ...functional moieties. However, one area yet to be explored is the base chemistry of the associated RNA molecules. Here we show the design and optimisation of hybrid DNA-RNA CRISPR and tracr molecules based on structure-guided approaches. Through careful mapping of the ribose requirements of Cas9, we develop hybrid versions possessing minimal RNA residues, which are sufficient to direct specific nuclease activity in vitro and in vivo with reduced off-target activity. We identify critical regions within these molecules that require ribose nucleotides and show a direct correlation between binding affinity/stability and cellular activity. This is the first demonstration of a non-RNA-guided Cas9 endonuclease and first step towards eliminating the ribose dependency of Cas9 to develop a XNA-programmable endonuclease.
Diese Schriftenreihe präsentiert eine strukturgeologische Neubewertung des Sächsischen Granulitgebirges, die aus einem multidisziplinären Datensatz abgeleitet wird. Die gewonnenen Ergebnisse münden ...in die Darstellung einer Bruchtektonischen Karte des Granulitgebirges und einen zusammenfassenden Katalog der Bruchstrukturen. Hierbei liegt ein Schwerpunkt des Projektes auf der Identifikation und Charakterisierung junger Störungszonen.
Die Veröffentlichung richtet sich sowohl an geologisch interessierte Laien ohne fachlichen Hintergrund als auch an ein Fachpublikum.
Redaktionsschluss: 31.10.2021
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