MESONET: Exploiting in situ protein unfolding to understand and control mesoscopic network formation
Lead Research Organisation:
University of Leeds
Department Name: Physics and Astronomy
Abstract
A major challenge in soft matter and biological physics is to construct a theory that connects the mechanical properties of an individual biopolymer and the collective response of a network of such biopolymers. While huge advancements have been made in the characterisation of biopolymers and their networks at the nanoscale and macroscale, the physics which describes the translation of mechanical properties across scales remains elusive. The key to unlocking this complexity is the use of Nature's bionanomachines-proteins as model systems, which possess evolutionary evolved stability and function, and which can be exploited to achieve in situ control of mesoscale network formation. My vision is to uncover the rich complexity of mesoscale protein network formation. I will achieve this through the development of a powerful suite of experimental and modelling tools which provide unprecedented access to force propagation and mesoscale network formation. A key strength of my approach is that the role of nanoscale changes and modifications in network architecture can be decoupled, so that they can be individually controlled to influence the network properties. I will develop rapid frame rate acquisition of in situ network formation to reveal how nanoscale mechanics and relaxation regulates mesoscale network formation. I will design and engineer mechanophores to measure force propagation and network relaxation at multiple length-and time-scales. I will exploit controlled mechanical deformation within the heterogeneous protein networks to yield novel technological advancements in designer soft matter for controlled small molecule diffusion and triggered release. This frontier science will deliver novel experimental and modelling tools for the soft matter community, uncover the fundamental physics which describes the translation of mechanics across scales and provide a paradigm shift in the design of soft matter materials for future applications.
Organisations
People |
ORCID iD |
| Lorna Dougan (Principal Investigator) |
Publications
Aufderhorst-Roberts A
(2022)
Power Law Rheology of Folded Protein Hydrogels
Aufderhorst-Roberts A
(2023)
Diversity of viscoelastic properties of an engineered muscle-inspired protein hydrogel
in Soft Matter
Brown C
(2022)
SAWstitch: exploring self-avoiding walks through hand embroidery
in Physics Education
Brown CP
(2023)
Structural and mechanical properties of folded protein hydrogels with embedded microbubbles.
in Biomaterials science
Cook KR
(2023)
Modelling network formation in folded protein hydrogels by cluster aggregation kinetics.
in Soft matter
Hughes MDG
(2023)
Building block aspect ratio controls assembly, architecture, and mechanics of synthetic and natural protein networks.
in Nature communications
Hughes MDG
(2025)
Competition between cross-linking and force-induced local conformational changes determines the structure and mechanics of labile protein networks.
in Journal of colloid and interface science
Hughes MDG
(2025)
Capturing Dynamic Assembly of Nanoscale Proteins During Network Formation.
in Small (Weinheim an der Bergstrasse, Germany)
Hughes MDG
(2022)
Tuning Protein Hydrogel Mechanics through Modulation of Nanoscale Unfolding and Entanglement in Postgelation Relaxation.
in ACS nano
Kpeglo D
(2022)
Modeling the mechanical stiffness of pancreatic ductal adenocarcinoma.
in Matrix biology plus
| Description | One aim of the project was to demonstrate that folded proteins can be exploited as functional building blocks in responsive biomaterials. This has been achieved in the paper "Nanomachine Networks: Functional All-Enzyme Hydrogels from Photochemical Cross-Linking of Glucose Oxidase." Enzymes are powerful because they act as catalysts due to their specificity and biocompatibility. We have developed a new approach for enzyme immobilization within "all-enzyme" hydrogels. This is achieved by forming photochemical covalent cross-links between the enzyme glucose oxidase. We demonstrate we can tune the structure and mechanics of the matrix and show that the enzyme remains functional in the biomaterial, the hydrogel. Another goal of the project was to understanding how a hydrogel network forms using a combination of scattering and rheology. This has been achieved. For example in the papers "Capturing the impact of protein unfolding on the dynamic assembly of protein networks" and "Capturing dynamic assembly of nanoscale proteins during network formation" we employ a combined time-resolved rheology and small-angle x-ray scattering (SAXS) approach to probe both the load-bearing structures and network architectures respectively. This is important as it provides a cross-length scale understanding of the network formation. Identifying the origin of the structural and mechanical properties of protein networks creates future opportunities to understand hierarchical biomechanics in vivo and develop functional, designed-for-purpose, biomaterials. We have developing new methods to capture the porosity of protein networks, for example "Unveiling the structure of protein-based hydrogels by overcoming cryo-SEM sample preparation challenges". Protein-based hydrogels have gained significant attention for their potential use in applications such as drug delivery and tissue engineering. Their internal structure is complex, spans across multiple length scales and affects their functionality, yet is not well understood because of folded proteins sensitivity to physical and chemical perturbations and the high water content of hydrogels. We have shown that cryo-scanning electron microscopy (cryo-SEM) has the potential to reveal such hierarchical structure when hydrated hydrogels are prepared with appropriate cryofixation. We show for photochemically cross-linked, folded globular bovine serum albumin (BSA) protein hydrogels that preparation artefacts are reduced by in-situ gelation, high pressure freezing (HPF), plasma focused ion beam (pFIB) milling, sublimation, and low dose secondary electron imaging. |
| Exploitation Route | We are currently exploring how to apply our materials for drug delivery applications, disease modelling and tissue engineering. |
| Sectors | Agriculture Food and Drink Chemicals Environment Healthcare Pharmaceuticals and Medical Biotechnology |
| Title | Capturing Dynamic Assembly of Nanoscale Proteins During Network Formation |
| Description | The structural evolution of hierarchical structures of nanoscale biomolecules is crucial for the construction of functional networks in vivo and in vitro. Despite the ubiquity of these networks, the physical mechanisms behind their formation and self-assembly remains poorly understood. Here, we use photochemically cross-linked folded protein hydrogels as a model biopolymer network system, with a combined time-resolved rheology and small-angle x-ray scattering (SAXS) approach to probe both the load-bearing structures and network architectures thereby providing a cross-length scale understanding of the network formation. Combining SAXS, rheology, and kinetic modelling, we propose a dual formation mechanism consisting of a primary formation phase, where monomeric folded proteins create the preliminary protein network scaffold; and a subsequent secondary formation phase, where both additional intra-networks crosslinks form and larger oligomers diffuse to join the preliminary network, leading to a denser more mechanically robust structure. Identifying this as the origin of the structural and mechanical properties of protein networks creates future opportunities to understand hierarchical biomechanics in vivo and develop functional, designed-for-purpose, biomaterials. |
| Type Of Material | Database/Collection of data |
| Year Produced | 2024 |
| Provided To Others? | Yes |
| URL | https://archive.researchdata.leeds.ac.uk/1340/ |