in-vesiculo-synthesis-peptide-membrane-precursors-for-autonomous

In Vesiculo Synthesis of Peptide Membrane Precursors for Autonomous Vesicle Growth

Compartmentalization of biochemical reactions is a central aspect of synthetic cells. For this purpose, peptide-based reaction compartments serve as an ...

Technische Universität München

Nanoscale plasmonic waveguides composed of metallic nanoparticles are capable of guiding electromagnetic energy below the optical diffraction limit. Signal feed-in and readout typically require the utilization of electronic effects or near-field optical techniques, whereas for their fabrication mainly lithographic methods are employed. Here we developed a switchable plasmonic waveguide assembled from gold nanoparticles (AuNPs) on a DNA origami structure that facilitates a simple spectroscopic excitation and readout. The waveguide is specifically excited at one end by a fluorescent dye, and energy transfer is detected at the other end via the fluorescence of a second dye. The transfer distance is beyond the multicolor FRET range and below the Abbé limit. The transmittance of the waveguide can also be reversibly switched by changing the position of a AuNP within the waveguide, which is tethered to the origami platform by a thermoresponsive peptide. High-yield fabrication of the plasmonic waveguides in bulk was achieved using silica particles as solid supports. Our findings enable bulk solution applications for plasmonic waveguides as light-focusing and light-polarizing elements below the diffraction limit.

Self-Assembled Active Plasmonic Waveguide with a Peptide-Based Thermomechanical Switch.

Membrane compartmentalization and growth are central aspects of living cells, and are thus encoded in every cell's genome. For the creation of artificial cellular systems, genetic information and production of membrane building blocks will need to be coupled in a similar manner. However, natural biochemical reaction networks and membrane building blocks are notoriously difficult to implement in vitro. Here, we utilized amphiphilic elastin-like peptides (ELP) to create self-assembled vesicular structures of about 200 nm diameter. In order to genetically encode the growth of these vesicles, we encapsulate a cell-free transcription-translation system together with the DNA template inside the peptide vesicles. We show in vesiculo production of a functioning fluorescent RNA aptamer and a fluorescent protein. Furthermore, we implement in situ expression of the membrane peptide itself and finally demonstrate autonomous vesicle growth due to the incorporation of this ELP into the membrane.

Towards synthetic cells using peptide-based reaction compartments.

In nature, compartmentalized and spatially organized enzyme cascades are utilized to increase the efficiency of enzymatic reactions. From a technologically relevant perspective, synthetic enzyme systems have to be optimized with emphasis on enzyme activity, productivity, scalability, and ease of use. But the underlying principles and relevant parameters that lead to an enhancement of the activity of enzyme cascades through spatial organization are still under debate. Here, we report on the 10-fold activity enhancement of the GOx-HRP enzyme cascade for the oxidation of luminol, when the enzymes are colocalized on micron-scaled solid scaffolds. Both enzymes were initially assembled and concentrated on DNA origami rectangles and finally further concentrated on the surface of silica particles. We show that each particular component of the designed system contributes to the activity enhancement. Furthermore, we measured an influence of the silica particle length scale on the total productivity by a factor of 5-10, but to a lesser extent on the maximum enzyme activity. Our findings demonstrate that micrometer-sized scaffolds can be used to enhance the efficiency of enzyme-cascades by at least a magnitude and that solid-phase scaffolds enable scalability for technological applications.

Article	Year
Self-Assembled Active Plasmonic Waveguide with a Peptide-Based Thermomechanical Switch. ACS nano\| PubMed ID: 28024323	2016
Towards synthetic cells using peptide-based reaction compartments. Nature communications\| PubMed ID: 30242152	2018
Enhanced Efficiency of an Enzyme Cascade on DNA-Activated Silica Surfaces. Langmuir : the ACS journal of surfaces and colloids\| PubMed ID: 30462511	2018

Kilian Vogele

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