1. |
- Arosio, Paolo, et al.
(author)
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Microfluidic Diffusion Analysis of the Sizes and Interactions of Proteins under Native Solution Conditions.
- 2016
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In: ACS Nano. - : American Chemical Society (ACS). - 1936-086X .- 1936-0851. ; 10:1, s. 333-341
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Journal article (peer-reviewed)abstract
- Characterizing the sizes and interactions of macromolecules under native conditions is a challenging problem in many areas of molecular sciences, which fundamentally arises from the polydisperse nature of biomolecular mixtures. Here, we describe a microfluidic platform for diffusional sizing based on monitoring micron-scale mass transport simultaneously in space and time. We show that the global analysis of such combined space-time data enables the hydrodynamic radii of individual species within mixtures to be determined directly by deconvoluting average signals into the contributions from the individual species. We demonstrate that the ability to perform rapid noninvasive sizing allows this method to be used to characterize interactions between biomolecules under native conditions. We illustrate the potential of the technique by implementing a single-step quantitative immunoassay that operates on a time scale of seconds and detects specific interactions between biomolecules within complex mixtures.
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2. |
- Yates, Emma V., et al.
(author)
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Latent analysis of unmodified biomolecules and their complexes in solution with attomole detection sensitivity
- 2015
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In: Nature Chemistry. - 1755-4330. ; 7:10, s. 802-809
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Journal article (peer-reviewed)abstract
- The study of biomolecular interactions is central to an understanding of function, malfunction and therapeutic modulation of biological systems, yet often involves a compromise between sensitivity and accuracy. Many conventional analytical steps and the procedures required to facilitate sensitive detection, such as the incorporation of chemical labels, are prone to perturb the complexes under observation. Here we present a 'latent' analysis approach that uses chemical and microfluidic tools to reveal, through highly sensitive detection of a labelled system, the behaviour of the physiologically relevant unlabelled system. We implement this strategy in a native microfluidic diffusional sizing platform, allowing us to achieve detection sensitivity at the attomole level, determine the hydrodynamic radii of biomolecules that vary by over three orders of magnitude in molecular weight, and study heterogeneous mixtures. We illustrate these key advantages by characterizing a complex of an antibody domain in the solution phase and under physiologically relevant conditions.
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3. |
- Munke, Anna, et al.
(author)
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Phage display and kinetic selection of antibodies that specifically inhibit amyloid self-replication
- 2017
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In: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 114:25, s. 6444-6449
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Journal article (peer-reviewed)abstract
- The aggregation of the amyloid β peptide (Aβ) into amyloid fibrils is a defining characteristic of Alzheimer’s disease. Because of the complexity of this aggregation process, effective therapeutic inhibitors will need to target the specific microscopic steps that lead to the production of neurotoxic species. We introduce a strategy for generating fibril-specific antibodies that selectively suppress fibril-dependent secondary nucleation of the 42-residue form of Aβ (Aβ42). We target this step because it has been shown to produce the majority of neurotoxic species during aggregation of Aβ42. Starting from large phage display libraries of single-chain antibody fragments (scFvs), the three-stage approach that we describe includes (i) selection of scFvs with high affinity for Aβ42 fibrils after removal of scFvs that bind Aβ42 in its monomeric form; (ii) ranking, by surface plasmon resonance affinity measurements, of the resulting candidate scFvs that bind to the Aβ42 fibrils; and (iii) kinetic screening and analysis to find the scFvs that inhibit selectively the fibril-catalyzed secondary nucleation process in Aβ42 aggregation. By applying this approach, we have identified four scFvs that inhibit specifically the fibril-dependent secondary nucleation process. Our method also makes it possible to discard antibodies that inhibit elongation, an important factor because the suppression of elongation does not target directly the production of toxic oligomers and may even lead to its increase. On the basis of our results, we suggest that the method described here could form the basis for rationally designed immunotherapy strategies to combat Alzheimer’s and related neurodegenerative diseases.
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4. |
- Shimanovich, Ulyana, et al.
(author)
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pH-Responsive Capsules with a Fibril Scaffold Shell Assembled from an Amyloidogenic Peptide
- 2021
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In: Small. - : Wiley. - 1613-6810 .- 1613-6829. ; 17:26
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Journal article (peer-reviewed)abstract
- Peptides and proteins have evolved to self-assemble into supramolecular entities through a set of non-covalent interactions. Such structures and materials provide the functional basis of life. Crucially, biomolecular assembly processes can be highly sensitive to and modulated by environmental conditions, including temperature, light, ionic strength and pH, providing the inspiration for the development of new classes of responsive functional materials based on peptide building blocks. Here, it is shown that the stimuli-responsive assembly of amyloidogenic peptide can be used as the basis of environmentally responsive microcapsules which exhibit release characteristics triggered by a change in pH. The microcapsules are biocompatible and biodegradable and may act as vehicles for controlled release of a wide range of biomolecules. Cryo-SEM images reveal the formation of a fibrillar network of the capsule interior with discrete compartments in which cargo molecules can be stored. In addition, the reversible formation of these microcapsules by modulating the solution pH is investigated and their potential application for the controlled release of encapsulated cargo molecules, including antibodies, is shown. These results suggest that the approach described here represents a promising venue for generating pH-responsive functional peptide-based materials for a wide range of potential applications for molecular encapsulation, storage, and release.
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