Biology subjects

Adamson, L.

Publications and source records attributed to Adamson, L..

4 recordsLinked to original sources

bioRxiv2026

First inhibitor of a bacterial two-partner secretion system.

Two-partner secretion system transporter proteins (TpsB) are widely conserved across Gram-negative pathogens. TpsB family proteins secrete exoprotein virulence factors that perform a myriad of functions such as adhesion and immune modulation. Despite their incredible importance in bacterial infectious disease, TpsB inhibitors have not yet been discovered. Here, we describe a potent inhibitor of FhaC, a TpsB protein produced by Bordetella spp. FhaC secretes the exoprotein FhaB that is essential for the establishment of whooping cough. We designed a peptide called P1 that we predicted would prevent substrate binding and lock FhaC in a secretion-inactive state. Simulations and biochemical assays supported our hypothesis and identified interactions important for P1 binding to FhaC. Strikingly, we observed that the peptide strongly inhibited FhaB secretion from clinical isolates and broadly reduced correlates of virulence. Together, this work provides a strong case for further development of a novel class of anti-TpsB anti-virulence compounds.

biochemistry↗

bioRxiv2024

High-fidelity in vitro packaging of diverse synthetic cargo into encapsulin protein cages

Cargo-filled protein cages are powerful tools in biotechnology with demonstrated potential as catalytic nanoreactors and vehicles for targeted drug delivery. While endogenous biomolecules can be packaged into protein cages during their expression and self-assembly inside cells, synthetic cargo molecules are typically incompatible with live cells and must be packaged in vitro. Here we report a fusion-based in vitro assembly method for packaging diverse synthetic cargo into encapsulin protein cages that outperforms standard in cellulo assembly, producing cages with superior uniformity and thermal stability. Fluorescent dyes, proteins and cytotoxic drug molecules can all be selectively packaged with high efficiency via a peptide-mediated targeting process. The exceptional fidelity and broad compatibility of our in vitro assembly platform enables generalisable access to cargo-filled protein cages that host novel synthetic functionality for diverse biotechnological applications.

biochemistry↗

bioRxiv2021

An artificial self-assembling nanocompartment for organising metabolic pathways in yeast

Metabolic pathways are commonly organised by sequestration into discrete cellular compartments. Compartments prevent unfavourable interactions with other pathways and provide local environments conducive to the activity of encapsulated enzymes. Such compartments are also useful synthetic biology tools for examining enzyme/pathway behaviour and for metabolic engineering. Here, we expand the intracellular compartmentalisation toolbox for budding yeast (Saccharomyces cerevisiae) with engineered Murine polyomavirus virus-like particles (MPyV VLPs). The MPyV system has two components: VP1 which self-assembles into the compartment shell; and a short anchor, VP2C, which mediates cargo protein encapsulation via binding to the inner surface of the VP1 shell. Destabilised GFP fused to VP2C was specifically sorted into VLPs and thereby protected from host-mediated degradation. In order to access metabolites of native and engineered yeast metabolism, VLP-based nanocompartments were directed to assemble in the cytosol by removal of the VP1 nuclear localisation signal. To demonstrate their ability to function as a metabolic compartment, MPyV VLPs were used to encapsulate myo-inositol oxygenase (MIOX), an unstable and rate-limiting enzyme in D-glucaric acid biosynthesis. Strains with encapsulated MIOX produced ~20% more D-glucaric acid compared to controls expressing free MIOX - despite accumulating dramatically less expressed protein - and also grew to higher cell densities. These effects were linked to enzyme stabilisation and mitigation of cellular toxicity by the engineered compartment. This is the first demonstration in yeast of an artificial biocatalytic compartment that can participate in a metabolic pathway and establishes the MPyV platform as a promising synthetic biology tool for yeast engineering.

synthetic biology↗

bioRxiv2021

Pore structure controls stability and molecular flux in engineered protein cages

Protein cages are a common architectural motif used by living organisms to compartmentalize and control biochemical reactions. While engineered protein cages have recently been featured in the construction of nanoreactors and synthetic organelles, relatively little is known about the underlying molecular parameters that govern cage stability and molecular flux through their pores. In this work, we systematically designed a 24-member library of protein cage variants based on the T. maritima encapsulin, each featuring pores of different size and charge. Twelve encapsulin pore variants were successfully assembled and purified, including eight designs with exceptional and prolonged thermal stability. While pores lined with negatively charged residues resulted in more robust assemblies than their corresponding positively charged variants, we were able to form stable assemblies covering a full range of pore sizes and charges, as observed in seven new cryo-EM structures of pore variants elucidated at resolutions between 2.5-3.6 [A]. Alongside these structures, molecular dynamics simulations and stopped flow kinetics experiments reveal the importance of considering both pore size and surface charge, together with flexibility and rate determining steps, when designing protein cages for controlling molecular flux. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=176 SRC="FIGDIR/small/428512v3_ufig1.gif" ALT="Figure 1"> View larger version (70K): org.highwire.dtl.DTLVardef@725e76org.highwire.dtl.DTLVardef@97a497org.highwire.dtl.DTLVardef@1b6ea1forg.highwire.dtl.DTLVardef@1c4d17f_HPS_FORMAT_FIGEXP M_FIG C_FIG

synthetic biology↗