bioRxiv Science⌕ Search

Biology subjects

Stucki, A.

Publications and source records attributed to Stucki, A..

2 recordsLinked to original sources

A multiplexed cell-free assay to screen for antimicrobial peptides in double emulsion droplets

The global surge in bacterial resistance against traditional antibiotics triggered intensive research for novel compounds, with antimicrobial peptides (AMPs) identified as a promising candidate. Automated methods to systematically generate and screen AMPs according to their membrane preference, however, are still lacking. We introduce a novel microfluidic system for the simultaneous cell-free production and screening of AMPs for their membrane specificity. On our device, AMPs are cell-free produced within water-in-oil-in-water double emulsion droplets, generated at high frequency. Within each droplet, the peptides can interact with different classes of co-encapsulated liposomes, generating a membrane-specific fluorescent signal. The double emulsions can be incubated and observed in a hydrodynamic trapping array or analysed via flow cytometry. Our approach provides a valuable tool for the discovery and development of membrane-active antimicrobials.

bioengineering↗

Single-Round Remodeling of the Active Site of an Artificial Metalloenzyme using an Ultrahigh-Throughput Double Emulsion Screening Assay

The potential of high-throughput compartmentalization renders droplet microfluidics an attractive tool for directed evolution of enzymes as it permits maintenance of the phenotype-genotype linkage throughout the entire optimization procedure. In particular, water-in-oil-in-water double emulsions droplets (DEs) produced by microfluidics enable the analysis of reaction compartments at ultra-high-throughput using commercially available fluorescence-activated cell sorting (FACS) devices. Here we report a streamlined method applicable for the ultrahigh-throughput screening of an artificial metalloenzyme (ArM), an artificial deallylase (ADAse), in double emulsions. The DE-protocol was validated by screening a four hundred member, double-mutant streptavidin library for the CpRu-catalyzed uncaging of aminocoumarin. The most active variants, identified by next generation sequencing of the sorted DE droplets with highest fluorescent intensity, are in good agreement with 96-well plate screening hits. These findings, thus, pave the way towards the systematic implementation of commercially available FACS for the directed evolution of metalloenzymes making ultrahigh-throughput screening more broadly accessible. The use of microfluidics for the formation of uniform compartments with precise control over reagents and cell encapsulation further facilitates the establishment of highly reliable quantitative assays.

biochemistry↗