Biology subjects

Gonzalez-Esquer, C. R.

Publications and source records attributed to Gonzalez-Esquer, C. R..

3 recordsLinked to original sources

bioRxiv2025

Metal-Triggered Rheological Switching in Engineered Lanmodulin Condensates

Reliable recovery of rare earth elements (REEs) is increasingly important for energy and communication technologies, yet current separation methods rely on harsh chemistries and are difficult to scale sustainably. Biological strategies offer a promising alternative but typically require immobilized proteins, introducing diffusion limitations and regeneration challenges. Here, we engineer a phase-separating variant of the high-affinity lanthanide-binding protein Lanmodulin (LanM) by fusing it to an encapsulation peptide (EP) microdomain. The resulting chimera, EP-LanM, undergoes liquid-liquid phase separation upon REE binding, forming condensates whose formation and dynamic properties are governed by metal stoichiometry and temperature. These condensates enable selective capture and release of La3 and Nd3 and support efficient recovery and reuse of the protein. Our findings show that metal-triggered protein condensation can be harnessed as an aqueous, reversible mechanism for REE enrichment, establishing a generalizable biophysical approach for designing functional phase-separating proteins for selective metal separation.

biophysics↗

bioRxiv2024

A blueprint for biomolecular condensation driven by bacterial microcompartment encapsulation peptides

Bacterial microcompartments (BMC) are protein organelles with diverse metabolic capabilities. Their functional diversity is determined by an enzymatic core that is sequestered within a structurally conserved protein shell architecture. Segregation of protein cargo into the BMC is enabled by encapsulation peptides (EPs), which are short helical domains fused to core proteins through a disordered linker. Here, we investigate how EPs drive multicomponent cargo assembly into biomolecular condensates. In vitro experiments supported by molecular dynamics simulations demonstrate the importance of both conserved hydrophobic packing and electrostatic interactions in stabilizing trimeric EP bundles. Topological rearrangements of EP domains can drive programmable liquid-or gel-like partitioning in vitro and in vivo. This partitioning is found to be EP-specific, modular and can co-assemble at least three fluorescent reporters. In summary, we describe the molecular features necessary to drive biomolecular condensation using a widespread peptide tag. This work can serve as a blueprint for implementing EP biotechnology across diverse applications.

molecular biology↗

bioRxiv2024

A robust synthetic biology toolkit to advance carboxysome study and design

Carboxysomes are polyhedral protein organelles that microorganisms use to facilitate carbon dioxide assimilation. They are composed of a modular protein shell which envelops an enzymatic core mainly comprised of physically coupled Rubisco and carbonic anhydrase. While the modular construction principles of carboxysomes make them attractive targets as customizable metabolic platforms, their size and complexity can be a hinderance. In this work, we design and validate a plasmid set - the pXpressome toolkit -in which -carboxysomes are robustly expressed and remain intact and functional after purification. We tested this toolkit by introducing mutations which influence carboxysome structure and performance. We find that deletion of vertex-capping genes results in formation of larger carboxysomes while deletion of facet forming genes produces smaller particles, suggesting that adjusting the ratio of these proteins can rationally affect morphology. Through a series of fluorescently labeled constructs, we observe this toolkit leads to more uniform expression and better cell health than previously published carboxysome expression systems. Overall, the pXpressome toolkit facilitates the study and redesign of carboxysomes with robust performance and improved phenotype uniformity. The pXpressome toolkit will support efforts to remodel carboxysomes for enhanced carbon fixation or serve as a platform for other nanoencapsulation goals.

synthetic biology↗