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Protein vesicles made from bioactive proteins have potential value in drug delivery, biocatalysis, and as artificial cells. As the proteins are produced recombinantly, the ability to precisely tune the protein sequence provides control not possible with polymeric vesicles. The tunability and biocompatibility motivated this work to develop protein vesicles using rationally designed protein building blocks to investigate how protein sequence influences vesicle self-assembly and properties. We have reported an elastin-like polypeptide (ELP) fused to an arginine-rich leucine zipper (ZR) and functional, globular proteins fused to a glutamate-rich leucine zipper (ZE) that self-assemble into protein vesicles when warmed from 4 to 25 °C due to the hydrophobic transition of ELP. Previously, we demonstrated the ability to tune vesicle properties by changing protein and salt concentration, ZE:ZR ratio, and warming rate. However, there is a limit to the properties that can be achieved via assembly conditions. In order to access a wider range of vesicle diameter and stability profiles, this work investigated how modifiying the hydrophobicity and length of the ELP sequence influenced self-assembly and the final properties of protein vesicles using mCherry as a model globular protein. The results showed that both transition temperature and diameter of protein vesicles were inversely correlated to the ELP guest residue hydrophobicity and the number of ELP pentapeptide repeats. Additionally, sequence manipulation enabled assembly of vesicles with properties not accessible by changes to assembly conditions. For example, introduction of tyrosine at 5 guest residue positions in ELP enabled formation of nanoscale vesicles stable at physiological salt concentration. This work yields design guidelines for modifying the ELP sequence to manipulate protein vesicle transition temperature, size and stability to achieve desired properties for particular biofunctional applications.
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This content will become publicly available on June 23, 2026
Rational Development of Recombinant ELP Bolaamphiphiles for the Controlled Construction of Multifunctionalized Globular Protein Vesicles
Abstract Synthetic biology has enabled the development of new strategies for creating artificial cells that can sense and respond to external stimuli. This study introduces the bottom-up construction of globular protein vesicles (GPVs) that incorporate elastin-like peptide (ELP) bolaamphiphiles as transmembrane components. To enable this strategy, we devised a Golden Gate-based cloning strategy to streamline the design, expression, and purification of ELP bolaamphiphiles. Three ELP bolamphiphiles with varying structural complexity were developed, incorporating fluorescent proteins to facilitate visualization and characterization. The self-assembly of these bolaamphiphiles into GPVs was optimized by varying the molar ratios of recombinant building blocks. Structural characterization confirmed vesicle formation, dynamic light scattering analysis revealed size distributions dependent on modular complexity, and atomic force microscopy demonstrated that the vesicles exhibited MPa-range Young’s moduli, indicative of high mechanical robustness. Our findings demonstrate that multifunctional ELP bolaamphiphiles can be incorporated into GPVs, enabling modular vesicle engineering. This work provides a foundation for designing synthetic cells with customizable bi-functionalities and modularity, advancing compartmentalized systems.
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- Award ID(s):
- 2123592
- PAR ID:
- 10648290
- Publisher / Repository:
- bioRxiv
- Date Published:
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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