1
|
Xu CK, Meisl G, Andrzejewska EA, Krainer G, Dear AJ, Castellana-Cruz M, Turi S, Edu IA, Vivacqua G, Jacquat RPB, Arter WE, Spillantini MG, Vendruscolo M, Linse S, Knowles TPJ. α-Synuclein oligomers form by secondary nucleation. Nat Commun 2024; 15:7083. [PMID: 39153989 PMCID: PMC11330488 DOI: 10.1038/s41467-024-50692-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2023] [Accepted: 07/19/2024] [Indexed: 08/19/2024] Open
Abstract
Oligomeric species arising during the aggregation of α-synuclein are implicated as a major source of toxicity in Parkinson's disease, and thus a major potential drug target. However, both their mechanism of formation and role in aggregation are largely unresolved. Here we show that, at physiological pH and in the absence of lipid membranes, α-synuclein aggregates form by secondary nucleation, rather than simple primary nucleation, and that this process is enhanced by agitation. Moreover, using a combination of single molecule and bulk level techniques, we identify secondary nucleation on the surfaces of existing fibrils, rather than formation directly from monomers, as the dominant source of oligomers. Our results highlight secondary nucleation as not only the key source of oligomers, but also the main mechanism of aggregate formation, and show that these processes take place under conditions which recapitulate the neutral pH and ionic strength of the cytosol.
Collapse
Affiliation(s)
- Catherine K Xu
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
- Max Planck Institute for the Science of Light, Erlangen, Germany
| | - Georg Meisl
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Ewa A Andrzejewska
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Georg Krainer
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
- Institute of Molecular Biosciences (IMB), University of Graz, Graz, Austria
| | - Alexander J Dear
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
- Biochemistry and Structural Biology, Lund University, Lund, Sweden
| | - Marta Castellana-Cruz
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Soma Turi
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Irina A Edu
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Giorgio Vivacqua
- Integrated Research Center (PRAAB), Campus Biomedico University of Rome, Rome, Italy
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Raphaël P B Jacquat
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
| | - William E Arter
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
| | | | - Michele Vendruscolo
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Sara Linse
- Biochemistry and Structural Biology, Lund University, Lund, Sweden
| | - Tuomas P J Knowles
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK.
- Cavendish Laboratory, University of Cambridge, Cambridge, UK.
| |
Collapse
|
2
|
Axell E, Hu J, Lindberg M, Dear AJ, Ortigosa-Pascual L, Andrzejewska EA, Šneiderienė G, Thacker D, Knowles TPJ, Sparr E, Linse S. The role of shear forces in primary and secondary nucleation of amyloid fibrils. Proc Natl Acad Sci U S A 2024; 121:e2322572121. [PMID: 38875148 PMCID: PMC11194593 DOI: 10.1073/pnas.2322572121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 05/02/2024] [Indexed: 06/16/2024] Open
Abstract
Shear forces affect self-assembly processes ranging from crystallization to fiber formation. Here, the effect of mild agitation on amyloid fibril formation was explored for four peptides and investigated in detail for A[Formula: see text]42, which is associated with Alzheimer's disease. To gain mechanistic insights into the effect of mild agitation, nonseeded and seeded aggregation reactions were set up at various peptide concentrations with and without an inhibitor. First, an effect on fibril fragmentation was excluded by comparing the monomer-concentration dependence of aggregation kinetics under idle and agitated conditions. Second, using a secondary nucleation inhibitor, Brichos, the agitation effect on primary nucleation was decoupled from secondary nucleation. Third, an effect on secondary nucleation was established in the absence of inhibitor. Fourth, an effect on elongation was excluded by comparing the seeding potency of fibrils formed under idle or agitated conditions. We find that both primary and secondary nucleation steps are accelerated by gentle agitation. The increased shear forces facilitate both the detachment of newly formed aggregates from catalytic surfaces and the rate at which molecules are transported in the bulk solution to encounter nucleation sites on the fibril and other surfaces. Ultrastructural evidence obtained with cryogenic transmission electron microscopy and free-flow electrophoresis in microfluidics devices imply that agitation speeds up the detachment of nucleated species from the fibril surface. Our findings shed light on the aggregation mechanism and the role of detachment for efficient secondary nucleation. The results inform on how to modulate the relative importance of different microscopic steps in drug discovery and investigations.
Collapse
Affiliation(s)
- Emil Axell
- Biochemistry and Structural Biology, Department of Chemistry, Lund University, SE-221 00Lund, Sweden
| | - Jing Hu
- Division of Physical Chemistry, Department of Chemistry, Lund University, SE-221 00Lund, Sweden
| | - Max Lindberg
- Biochemistry and Structural Biology, Department of Chemistry, Lund University, SE-221 00Lund, Sweden
| | - Alexander J. Dear
- Biochemistry and Structural Biology, Department of Chemistry, Lund University, SE-221 00Lund, Sweden
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, Cambridge University, CB2 1EWCambridge, United Kingdom
| | - Lei Ortigosa-Pascual
- Biochemistry and Structural Biology, Department of Chemistry, Lund University, SE-221 00Lund, Sweden
| | - Ewa A. Andrzejewska
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, Cambridge University, CB2 1EWCambridge, United Kingdom
| | - Greta Šneiderienė
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, Cambridge University, CB2 1EWCambridge, United Kingdom
| | - Dev Thacker
- Biochemistry and Structural Biology, Department of Chemistry, Lund University, SE-221 00Lund, Sweden
| | - Tuomas P. J. Knowles
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, Cambridge University, CB2 1EWCambridge, United Kingdom
| | - Emma Sparr
- Division of Physical Chemistry, Department of Chemistry, Lund University, SE-221 00Lund, Sweden
| | - Sara Linse
- Biochemistry and Structural Biology, Department of Chemistry, Lund University, SE-221 00Lund, Sweden
| |
Collapse
|
3
|
Dear A, Thacker D, Wennmalm S, Ortigosa-Pascual L, Andrzejewska EA, Meisl G, Linse S, Knowles TPJ. Aβ Oligomer Dissociation Is Catalyzed by Fibril Surfaces. ACS Chem Neurosci 2024; 15:2296-2307. [PMID: 38785363 PMCID: PMC11157482 DOI: 10.1021/acschemneuro.4c00127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Revised: 04/21/2024] [Accepted: 04/23/2024] [Indexed: 05/25/2024] Open
Abstract
Oligomeric assemblies consisting of only a few protein subunits are key species in the cytotoxicity of neurodegenerative disorders, such as Alzheimer's and Parkinson's diseases. Their lifetime in solution and abundance, governed by the balance of their sources and sinks, are thus important determinants of disease. While significant advances have been made in elucidating the processes that govern oligomer production, the mechanisms behind their dissociation are still poorly understood. Here, we use chemical kinetic modeling to determine the fate of oligomers formed in vitro and discuss the implications for their abundance in vivo. We discover that oligomeric species formed predominantly on fibril surfaces, a broad class which includes the bulk of oligomers formed by the key Alzheimer's disease-associated Aβ peptides, also dissociate overwhelmingly on fibril surfaces, not in solution as had previously been assumed. We monitor this "secondary nucleation in reverse" by measuring the dissociation of Aβ42 oligomers in the presence and absence of fibrils via two distinct experimental methods. Our findings imply that drugs that bind fibril surfaces to inhibit oligomer formation may also inhibit their dissociation, with important implications for rational design of therapeutic strategies for Alzheimer's and other amyloid diseases.
Collapse
Affiliation(s)
- Alexander
J. Dear
- Biochemistry
and Structural Biology, Lund University, Lund 221 00, Sweden
- Centre
for Misfolding Diseases Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K.
| | - Dev Thacker
- Biochemistry
and Structural Biology, Lund University, Lund 221 00, Sweden
| | - Stefan Wennmalm
- Department
of Applied Physics, Biophysics Group, SciLifeLab, Royal Institute of Technology-KTH, Solna 171 65, Sweden
| | | | - Ewa A. Andrzejewska
- Centre
for Misfolding Diseases Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K.
| | - Georg Meisl
- Centre
for Misfolding Diseases Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K.
| | - Sara Linse
- Biochemistry
and Structural Biology, Lund University, Lund 221 00, Sweden
| | - Tuomas P. J. Knowles
- Centre
for Misfolding Diseases Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K.
- Cavendish
Laboratory, University of Cambridge, J J Thomson Avenue, Cambridge CB3 0HE, U.K.
| |
Collapse
|
4
|
Horne RI, Andrzejewska EA, Alam P, Brotzakis ZF, Srivastava A, Aubert A, Nowinska M, Gregory RC, Staats R, Possenti A, Chia S, Sormanni P, Ghetti B, Caughey B, Knowles TPJ, Vendruscolo M. Discovery of potent inhibitors of α-synuclein aggregation using structure-based iterative learning. Nat Chem Biol 2024; 20:634-645. [PMID: 38632492 PMCID: PMC11062903 DOI: 10.1038/s41589-024-01580-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 02/12/2024] [Indexed: 04/19/2024]
Abstract
Machine learning methods hold the promise to reduce the costs and the failure rates of conventional drug discovery pipelines. This issue is especially pressing for neurodegenerative diseases, where the development of disease-modifying drugs has been particularly challenging. To address this problem, we describe here a machine learning approach to identify small molecule inhibitors of α-synuclein aggregation, a process implicated in Parkinson's disease and other synucleinopathies. Because the proliferation of α-synuclein aggregates takes place through autocatalytic secondary nucleation, we aim to identify compounds that bind the catalytic sites on the surface of the aggregates. To achieve this goal, we use structure-based machine learning in an iterative manner to first identify and then progressively optimize secondary nucleation inhibitors. Our results demonstrate that this approach leads to the facile identification of compounds two orders of magnitude more potent than previously reported ones.
Collapse
Affiliation(s)
- Robert I Horne
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Ewa A Andrzejewska
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Parvez Alam
- Laboratory of Neurological Infections and Immunity, Rocky Mountain Laboratories, National Institute for Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Z Faidon Brotzakis
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Ankit Srivastava
- Laboratory of Neurological Infections and Immunity, Rocky Mountain Laboratories, National Institute for Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Alice Aubert
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Magdalena Nowinska
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Rebecca C Gregory
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Roxine Staats
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Andrea Possenti
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Sean Chia
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
- Bioprocessing Technology Institute, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore
| | - Pietro Sormanni
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Bernardino Ghetti
- Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Byron Caughey
- Laboratory of Neurological Infections and Immunity, Rocky Mountain Laboratories, National Institute for Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Tuomas P J Knowles
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Michele Vendruscolo
- Centre for Misfolding Diseases, Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK.
| |
Collapse
|
5
|
Douma C, Bowser MT. Assessing Surface Adsorption in Cyclic Olefin Copolymer Microfluidic Devices Using Two-Dimensional Nano Liquid Chromatography-Micro Free Flow Electrophoresis Separations. Anal Chem 2023; 95:18379-18387. [PMID: 38060457 PMCID: PMC10733905 DOI: 10.1021/acs.analchem.3c03014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 10/11/2023] [Accepted: 10/18/2023] [Indexed: 12/20/2023]
Abstract
Surface interactions are a concern in microscale separations, where analyte adsorption can decrease the speed, sensitivity, and resolution otherwise achieved by miniaturization. Here, we functionally characterize the surface adsorption of hot-embossed cyclic olefin copolymer (COC) micro free-flow electrophoresis (μFFE) devices using two-dimensional nLC × μFFE separations, which introduce a 3- to 5 s plug of analyte into the device and measure temporal broadening that arises from surface interactions. COC is an attractive material for microfluidic devices, but little is known about its potential for surface adsorption in applications with continuous fluid flow and temporal measurements. Adsorption was minimal for three small molecule dyes: positively charged rhodamine 123, negatively charged fluorescein, and neutral rhodamine 110. Temporal peak widths for the three dyes ranged from 3 to 7 s and did not change significantly with increasing transit distance. Moderate adsorption was observed for Chromeo P503-labeled myoglobin and cytochrome c with temporal peak widths around 20 s. Overall, the COC surface adsorption was low compared to traditional glass devices, where peak widths are on the order of minutes. Improvements in durability, long-term performance, and ease of fabrication, combined with low overall adsorption, make the COC μFFE devices a practical choice for applications involving time-resolved continuous detection.
Collapse
Affiliation(s)
- Cecilia
C. Douma
- Department of Chemistry, University
of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| | - Michael T. Bowser
- Department of Chemistry, University
of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| |
Collapse
|
6
|
Sasanian N, Sharma R, Lubart Q, Kk S, Ghaeidamini M, Dorfman KD, Esbjörner EK, Westerlund F. Probing physical properties of single amyloid fibrils using nanofluidic channels. NANOSCALE 2023; 15:18737-18744. [PMID: 37953701 DOI: 10.1039/d3nr02740f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2023]
Abstract
Amyloid fibril formation is central to the pathology of many diseases, including neurodegenerative disorders such as Alzheimer's and Parkinson's disease. Amyloid fibrils can also have functional and scaffolding roles, for example in bacterial biofilms, and have also been exploited as useful biomaterials. Despite being linear protein homopolymers, amyloid fibrils can exhibit significant structural and morphological polymorphism, making it relevant to study them on the single fibril level. We here introduce the concept of nanofluidic channel analysis to the study of single, fluorescently-labeled amyloid fibrils in solution, monitoring the extension and emission intensity of individual fibrils confined in nanochannels with a depth of 300 nm and a width that gradually increases from 300 to 3000 nm. The change in fibril extension with channel width permitted accurate determination of the persistence length of individual fibrils using Odijk's theory for strongly confined polymers. The technique was applied to amyloid fibrils prepared from the Alzheimer's related peptide amyloid-β(1-42) and the Parkinson's related protein α-synuclein, obtaining mean persistence lengths of 5.9 ± 4.5 μm and 3.0 ± 1.6 μm, respectively. The broad distributions of fibril persistence lengths indicate that amyloid fibril polymorphism can manifest in their physical properties. Interestingly, the α-synuclein fibrils had lower persistence lengths than the amyloid-β(1-42) fibrils, despite being thicker. Furthermore, there was no obvious within-sample correlation between the fluorescence emission intensity per unit length of the labelled fibrils and their persistence lengths, suggesting that stiffness may not be proportional to thickness. We foresee that the nanofluidics methodology established here will be a useful tool to study amyloid fibrils on the single fibril level to gain information on heterogeneity in their physical properties and interactions.
Collapse
Affiliation(s)
- Nima Sasanian
- Division of Chemical Biology, Department of Life Sciences, Chalmers University of Technology, Kemivägen 10, 412 96 Gothenburg, Sweden.
| | - Rajhans Sharma
- Division of Chemical Biology, Department of Life Sciences, Chalmers University of Technology, Kemivägen 10, 412 96 Gothenburg, Sweden.
| | - Quentin Lubart
- Division of Chemical Biology, Department of Life Sciences, Chalmers University of Technology, Kemivägen 10, 412 96 Gothenburg, Sweden.
| | - Sriram Kk
- Division of Chemical Biology, Department of Life Sciences, Chalmers University of Technology, Kemivägen 10, 412 96 Gothenburg, Sweden.
| | - Marziyeh Ghaeidamini
- Division of Chemical Biology, Department of Life Sciences, Chalmers University of Technology, Kemivägen 10, 412 96 Gothenburg, Sweden.
| | - Kevin D Dorfman
- Department of Chemical Engineering and Materials Science, University of Minnesota-Twin Cities, 421 Washington Ave SE, Minneapolis, Minnesota 55455, USA
| | - Elin K Esbjörner
- Division of Chemical Biology, Department of Life Sciences, Chalmers University of Technology, Kemivägen 10, 412 96 Gothenburg, Sweden.
| | - Fredrik Westerlund
- Division of Chemical Biology, Department of Life Sciences, Chalmers University of Technology, Kemivägen 10, 412 96 Gothenburg, Sweden.
| |
Collapse
|
7
|
Sneideris T, Erkamp NA, Ausserwöger H, Saar KL, Welsh TJ, Qian D, Katsuya-Gaviria K, Johncock MLLY, Krainer G, Borodavka A, Knowles TPJ. Targeting nucleic acid phase transitions as a mechanism of action for antimicrobial peptides. Nat Commun 2023; 14:7170. [PMID: 37935659 PMCID: PMC10630377 DOI: 10.1038/s41467-023-42374-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 10/10/2023] [Indexed: 11/09/2023] Open
Abstract
Antimicrobial peptides (AMPs), which combat bacterial infections by disrupting the bacterial cell membrane or interacting with intracellular targets, are naturally produced by a number of different organisms, and are increasingly also explored as therapeutics. However, the mechanisms by which AMPs act on intracellular targets are not well understood. Using machine learning-based sequence analysis, we identified a significant number of AMPs that have a strong tendency to form liquid-like condensates in the presence of nucleic acids through phase separation. We demonstrate that this phase separation propensity is linked to the effectiveness of the AMPs in inhibiting transcription and translation in vitro, as well as their ability to compact nucleic acids and form clusters with bacterial nucleic acids in bacterial cells. These results suggest that the AMP-driven compaction of nucleic acids and modulation of their phase transitions constitute a previously unrecognised mechanism by which AMPs exert their antibacterial effects. The development of antimicrobials that target nucleic acid phase transitions may become an attractive route to finding effective and long-lasting antibiotics.
Collapse
Affiliation(s)
- Tomas Sneideris
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, UK
| | - Nadia A Erkamp
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, UK
| | - Hannes Ausserwöger
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, UK
| | - Kadi L Saar
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, UK
| | - Timothy J Welsh
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, UK
| | - Daoyuan Qian
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, UK
| | - Kai Katsuya-Gaviria
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, UK
| | - Margaret L L Y Johncock
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, UK
| | - Georg Krainer
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, UK
| | - Alexander Borodavka
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, UK.
| | - Tuomas P J Knowles
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, UK.
- Cavendish Laboratory, Department of Physics, University of Cambridge, J J Thomson Ave, Cambridge, UK.
| |
Collapse
|
8
|
Krainer G, Saar KL, Arter WE, Welsh TJ, Czekalska MA, Jacquat RPB, Peter Q, Traberg WC, Pujari A, Jayaram AK, Challa P, Taylor CG, van der Linden LM, Franzmann T, Owens RM, Alberti S, Klenerman D, Knowles TPJ. Direct digital sensing of protein biomarkers in solution. Nat Commun 2023; 14:653. [PMID: 36746944 PMCID: PMC9902533 DOI: 10.1038/s41467-023-35792-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 01/03/2023] [Indexed: 02/08/2023] Open
Abstract
The detection of proteins is of central importance to biomolecular analysis and diagnostics. Typical immunosensing assays rely on surface-capture of target molecules, but this constraint can limit specificity, sensitivity, and the ability to obtain information beyond simple concentration measurements. Here we present a surface-free, single-molecule microfluidic sensing platform for direct digital protein biomarker detection in solution, termed digital immunosensor assay (DigitISA). DigitISA is based on microchip electrophoretic separation combined with single-molecule detection and enables absolute number/concentration quantification of proteins in a single, solution-phase step. Applying DigitISA to a range of targets including amyloid aggregates, exosomes, and biomolecular condensates, we demonstrate that the assay provides information beyond stoichiometric interactions, and enables characterization of immunochemistry, binding affinity, and protein biomarker abundance. Taken together, our results suggest a experimental paradigm for the sensing of protein biomarkers, which enables analyses of targets that are challenging to address using conventional immunosensing approaches.
Collapse
Affiliation(s)
- Georg Krainer
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
| | - Kadi L Saar
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
| | - William E Arter
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
| | - Timothy J Welsh
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
| | - Magdalena A Czekalska
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK.,Fluidic Analytics Limited, Unit A The Paddocks Business Centre, Cherry Hinton Road, Cambridge, CB1 8DH, UK
| | - Raphaël P B Jacquat
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
| | - Quentin Peter
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
| | - Walther C Traberg
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge, CB3 0AS, UK
| | - Arvind Pujari
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK.,Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge, CB3 0AS, UK
| | - Akhila K Jayaram
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
| | - Pavankumar Challa
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
| | - Christopher G Taylor
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
| | - Lize-Mari van der Linden
- Biotechnology Center (BIOTEC), Center for Molecular and Cellular Bioengineering (CMCB), Technische Universität Dresden, Tatzberg 47/49, Dresden, Germany
| | - Titus Franzmann
- Biotechnology Center (BIOTEC), Center for Molecular and Cellular Bioengineering (CMCB), Technische Universität Dresden, Tatzberg 47/49, Dresden, Germany
| | - Roisin M Owens
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge, CB3 0AS, UK
| | - Simon Alberti
- Biotechnology Center (BIOTEC), Center for Molecular and Cellular Bioengineering (CMCB), Technische Universität Dresden, Tatzberg 47/49, Dresden, Germany
| | - David Klenerman
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
| | - Tuomas P J Knowles
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK. .,Cavendish Laboratory, Department of Physics, University of Cambridge, J J Thomson Ave, Cambridge, CB3 0HE, UK.
| |
Collapse
|
9
|
Couceiro P, Alonso-Chamarro J. Fluorescence Imaging Characterization of the Separation Process in a Monolithic Microfluidic Free-Flow Electrophoresis Device Fabricated Using Low-Temperature Co-Fired Ceramics. MICROMACHINES 2022; 13:mi13071023. [PMID: 35888840 PMCID: PMC9324176 DOI: 10.3390/mi13071023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 06/22/2022] [Accepted: 06/24/2022] [Indexed: 11/26/2022]
Abstract
A monolithic microfluidic free-flow electrophoresis device, fabricated using low-temperature co-fired ceramic technology, is presented. The device integrates gold electrodes and a 20 µm thick transparent ceramic optical window, suitable for fluorescence imaging, into a multilevel microfluidic chamber design. The microfluidic chamber consists of a 60 µm deep separation chamber and two, 50 µm deep electrode chambers separated by 10 µm deep side channel arrays. Fluorescence imaging was used for in-chip, spatial-temporal characterization of local pH variations in separation conditions as well as to characterize the separation process. The device allowed baseline resolution separation of a sample mixture of Fluorescein, Rhodamine 6G, and 4-Methylumbelliferone at pH 7.0, in only 6 s, using 378 V.s/cm. The results demonstrate the possibility of studying a chemical process using fluorescence imaging within the traditional fields of low-temperature co-fired ceramics technology, such as high-electrical-field applications, while using a simple fabrication procedure suitable for low-cost mass production.
Collapse
|
10
|
Welsh TJ, Krainer G, Espinosa JR, Joseph JA, Sridhar A, Jahnel M, Arter WE, Saar KL, Alberti S, Collepardo-Guevara R, Knowles TPJ. Surface Electrostatics Govern the Emulsion Stability of Biomolecular Condensates. NANO LETTERS 2022; 22:612-621. [PMID: 35001622 DOI: 10.1021/acs.nanolett.1c03138] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Liquid-liquid phase separation underlies the formation of biological condensates. Physically, such systems are microemulsions that in general have a propensity to fuse and coalesce; however, many condensates persist as independent droplets in the test tube and inside cells. This stability is crucial for their function, but the physicochemical mechanisms that control the emulsion stability of condensates remain poorly understood. Here, by combining single-condensate zeta potential measurements, optical microscopy, tweezer experiments, and multiscale molecular modeling, we investigate how the nanoscale forces that sustain condensates impact their stability against fusion. By comparing peptide-RNA (PR25:PolyU) and proteinaceous (FUS) condensates, we show that a higher condensate surface charge correlates with a lower fusion propensity. Moreover, measurements of single condensate zeta potentials reveal that such systems can constitute classically stable emulsions. Taken together, these results highlight the role of passive stabilization mechanisms in protecting biomolecular condensates against coalescence.
Collapse
Affiliation(s)
- Timothy J Welsh
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K
| | - Georg Krainer
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K
| | - Jorge R Espinosa
- Cavendish Laboratory, University of Cambridge, J J Thomson Avenue, Cambridge CB3 0HE, U.K
| | - Jerelle A Joseph
- Cavendish Laboratory, University of Cambridge, J J Thomson Avenue, Cambridge CB3 0HE, U.K
| | - Akshay Sridhar
- Cavendish Laboratory, University of Cambridge, J J Thomson Avenue, Cambridge CB3 0HE, U.K
| | - Marcus Jahnel
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstr. 108, 01307 Dresden, Germany
- Biotechnology Center (BIOTEC), Center for Molecular and Cellular Bioengineering (CMCB), Technische Universität Dresden, Tatzberg 47/49, 01307 Dresden, Germany
- Cluster of Excellence "Physics of Life", TU Dresden, Dresden 01307, Germany
| | - William E Arter
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K
| | - Kadi L Saar
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K
| | - Simon Alberti
- Biotechnology Center (BIOTEC), Center for Molecular and Cellular Bioengineering (CMCB), Technische Universität Dresden, Tatzberg 47/49, 01307 Dresden, Germany
| | - Rosana Collepardo-Guevara
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K
- Cavendish Laboratory, University of Cambridge, J J Thomson Avenue, Cambridge CB3 0HE, U.K
- Department of Genetics, University of Cambridge, Cambridge CB2 3EH, U.K
| | - Tuomas P J Knowles
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K
- Cavendish Laboratory, University of Cambridge, J J Thomson Avenue, Cambridge CB3 0HE, U.K
| |
Collapse
|
11
|
Arter WE, Saar KL, Herling TW, Knowles TPJ. Microchip Free-Flow Electrophoresis for Bioanalysis, Sensing, and Purification. Methods Mol Biol 2022; 2394:249-266. [PMID: 35094333 DOI: 10.1007/978-1-0716-1811-0_16] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The separation of complex mixtures is ubiquitous throughout molecular biology, and techniques such as gel-based electrophoresis are common laboratory practice. Such methods are not without their drawbacks, however, which include non-specific interactions between analyte and the separation matrix, poor yields in purification and non-continuous analyte throughput. Microfluidic techniques, which exploit physical phenomena unique to the microscale, promise to improve many aspects of traditional laboratory procedures. These methods offer a quantitative, solution-based alternative to traditional gel electrophoresis, with rapid measurement times enabling the analysis of transient or weak biomolecular interactions that would be challenging to observe with traditional methods. Here, we present a protocol for the lithographic fabrication and operation of microfluidic chips capable of free-flow electrophoretic (FFE) fractionation and analysis of biological analytes. We demonstrate the efficacy of our approach through a protein-sensing methodology based on FFE fractionation of DNA-protein mixtures. In addition, the FFE technique described here can be readily adapted to suit a variety of preparative and analytical applications, providing information on the charge, zeta-potential, and interactions of analytes.
Collapse
Affiliation(s)
- William E Arter
- Department of Chemistry, University of Cambridge, Cambridge, UK
- Cavendish Laboratory, University of Cambridge, Cambridge, UK
| | - Kadi L Saar
- Department of Chemistry, University of Cambridge, Cambridge, UK
| | | | - Tuomas P J Knowles
- Department of Chemistry, University of Cambridge, Cambridge, UK.
- Cavendish Laboratory, University of Cambridge, Cambridge, UK.
| |
Collapse
|
12
|
Zhang Y, Wright MA, Saar KL, Challa P, Morgunov AS, Peter QAE, Devenish S, Dobson CM, Knowles TPJ. Machine learning-aided protein identification from multidimensional signatures. LAB ON A CHIP 2021; 21:2922-2931. [PMID: 34109955 PMCID: PMC8314522 DOI: 10.1039/d0lc01148g] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 03/16/2021] [Indexed: 06/12/2023]
Abstract
The ability to determine the identity of specific proteins is a critical challenge in many areas of cellular and molecular biology, and in medical diagnostics. Here, we present a macine learning aided microfluidic protein characterisation strategy that within a few minutes generates a three-dimensional fingerprint of a protein sample indicative of its amino acid composition and size and, thereby, creates a unique signature for the protein. By acquiring such multidimensional fingerprints for a set of ten proteins and using machine learning approaches to classify the fingerprints, we demonstrate that this strategy allows proteins to be classified at a high accuracy, even though classification using a single dimension is not possible. Moreover, we show that the acquired fingerprints correlate with the amino acid content of the samples, which makes it is possible to identify proteins directly from their sequence without requiring any prior knowledge about the fingerprints. These findings suggest that such a multidimensional profiling strategy can lead to the development of a novel method for protein identification in a microfluidic format.
Collapse
Affiliation(s)
- Yuewen Zhang
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK.
| | - Maya A Wright
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK.
| | - Kadi L Saar
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK. and Cavendish Laboratory, Department of Physics, University of Cambridge, J J Thomson Ave, Cambridge CB3 0HE, UK
| | - Pavankumar Challa
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK.
| | - Alexey S Morgunov
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK. and Fluidic Analytics Ltd., Cambridge, UK
| | - Quentin A E Peter
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK.
| | | | - Christopher M Dobson
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK.
| | - Tuomas P J Knowles
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK. and Cavendish Laboratory, Department of Physics, University of Cambridge, J J Thomson Ave, Cambridge CB3 0HE, UK
| |
Collapse
|
13
|
Karami N, KK S, Yazdanshenas S, Lin YL, Jaén-Luchoro D, Ekedahl E, Parameshwaran S, Lindblom A, Åhrén C, Westerlund F. Identity of blaCTX-M Carrying Plasmids in Sequential ESBL- E. coli Isolates from Patients with Recurrent Urinary Tract Infections. Microorganisms 2021; 9:microorganisms9061138. [PMID: 34070515 PMCID: PMC8226486 DOI: 10.3390/microorganisms9061138] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 05/10/2021] [Accepted: 05/20/2021] [Indexed: 11/16/2022] Open
Abstract
Plasmid-mediated multidrug resistance in E. coli is becoming increasingly prevalent. Considering this global threat to human health, it is important to understand how plasmid-mediated resistance spreads. From a cohort of 123 patients with recurrent urinary tract infections (RUTI) due to extended spectrum beta-lactamase (ESBL)-producing Escherichia coli (ESBL E. coli), only five events with a change of ESBL E. coli strain between RUTI episodes were identified. Their blaCTX-M encoding plasmids were compared within each pair of isolates using optical DNA mapping (ODM) and PCR-based replicon typing. Despite similar blaCTX-M genes and replicon types, ODM detected only one case with identical plasmids in the sequential ESBL E. coli strains, indicating that plasmid transfer could have occurred. For comparison, plasmids from seven patients with the same ESBL E. coli strain reoccurring in both episodes were analyzed. These plasmids (encoding blaCTX-M-3, blaCTX-M-14, and blaCTX-M-15) were unaltered for up to six months between recurrent infections. Thus, transmission of blaCTX-M plasmids appears to be a rare event during the course of RUTI. Despite the limited number (n = 23) of plasmids investigated, similar blaCTX-M-15 plasmids in unrelated isolates from different patients were detected, suggesting that some successful plasmids could be associated with specific strains, or are more easily transmitted.
Collapse
Affiliation(s)
- Nahid Karami
- Institute of Biomedicine, Department of Infectious Diseases and Centre for Antibiotic Resistance Research (CARe), University of Gothenburg, Guldhedsgatan 10 A, 413 46 Gothenburg, Sweden; (S.Y.); (D.J.-L.); (A.L.); (C.Å.)
- Västra Götaland Region, Sahlgrenska University Hospital, Department of Clinical Microbiology, Guldhedsgatan 10A, 413 46 Gothenburg, Sweden
- Correspondence: (N.K.); (F.W.); Tel.: +46-31-342-6173 (N.K.); +46-31-772-3049 (F.W.)
| | - Sriram KK
- Department of Biology and Biological Engineering, Chalmers University of Technology, Kemivagen 10, 412 96 Gothenburg, Sweden; (S.K.); (Y.-L.L.); (E.E.); (S.P.)
| | - Shora Yazdanshenas
- Institute of Biomedicine, Department of Infectious Diseases and Centre for Antibiotic Resistance Research (CARe), University of Gothenburg, Guldhedsgatan 10 A, 413 46 Gothenburg, Sweden; (S.Y.); (D.J.-L.); (A.L.); (C.Å.)
- Västra Götaland Region, Sahlgrenska University Hospital, Department of Clinical Microbiology, Guldhedsgatan 10A, 413 46 Gothenburg, Sweden
| | - Yii-Lih Lin
- Department of Biology and Biological Engineering, Chalmers University of Technology, Kemivagen 10, 412 96 Gothenburg, Sweden; (S.K.); (Y.-L.L.); (E.E.); (S.P.)
| | - Daniel Jaén-Luchoro
- Institute of Biomedicine, Department of Infectious Diseases and Centre for Antibiotic Resistance Research (CARe), University of Gothenburg, Guldhedsgatan 10 A, 413 46 Gothenburg, Sweden; (S.Y.); (D.J.-L.); (A.L.); (C.Å.)
| | - Elina Ekedahl
- Department of Biology and Biological Engineering, Chalmers University of Technology, Kemivagen 10, 412 96 Gothenburg, Sweden; (S.K.); (Y.-L.L.); (E.E.); (S.P.)
| | - Sanjana Parameshwaran
- Department of Biology and Biological Engineering, Chalmers University of Technology, Kemivagen 10, 412 96 Gothenburg, Sweden; (S.K.); (Y.-L.L.); (E.E.); (S.P.)
| | - Anna Lindblom
- Institute of Biomedicine, Department of Infectious Diseases and Centre for Antibiotic Resistance Research (CARe), University of Gothenburg, Guldhedsgatan 10 A, 413 46 Gothenburg, Sweden; (S.Y.); (D.J.-L.); (A.L.); (C.Å.)
- Västra Götaland Region, Sahlgrenska University Hospital, Department of Clinical Microbiology, Guldhedsgatan 10A, 413 46 Gothenburg, Sweden
| | - Christina Åhrén
- Institute of Biomedicine, Department of Infectious Diseases and Centre for Antibiotic Resistance Research (CARe), University of Gothenburg, Guldhedsgatan 10 A, 413 46 Gothenburg, Sweden; (S.Y.); (D.J.-L.); (A.L.); (C.Å.)
- Swedish Strategic Program against Antimicrobial Resistance (Strama), Västra Götaland Region, Regionens Hus, 405 44 Gothenburg, Sweden
| | - Fredrik Westerlund
- Department of Biology and Biological Engineering, Chalmers University of Technology, Kemivagen 10, 412 96 Gothenburg, Sweden; (S.K.); (Y.-L.L.); (E.E.); (S.P.)
- Correspondence: (N.K.); (F.W.); Tel.: +46-31-342-6173 (N.K.); +46-31-772-3049 (F.W.)
| |
Collapse
|
14
|
Arter WE, Xu CK, Castellana-Cruz M, Herling TW, Krainer G, Saar KL, Kumita JR, Dobson CM, Knowles TPJ. Rapid Structural, Kinetic, and Immunochemical Analysis of Alpha-Synuclein Oligomers in Solution. NANO LETTERS 2020; 20:8163-8169. [PMID: 33079553 PMCID: PMC7116857 DOI: 10.1021/acs.nanolett.0c03260] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Oligomers comprised of misfolded proteins are implicated as neurotoxins in the pathogenesis of protein misfolding conditions such as Parkinson's and Alzheimer's diseases. Structural, biophysical, and biochemical characterization of these nanoscale protein assemblies is key to understanding their pathology and the design of therapeutic interventions, yet it is challenging due to their heterogeneous, transient nature and low relative abundance in complex mixtures. Here, we demonstrate separation of heterogeneous populations of oligomeric α-synuclein, a protein central to the pathology of Parkinson's disease, in solution using microfluidic free-flow electrophoresis. We characterize nanoscale structural heterogeneity of transient oligomers on a time scale of seconds, at least 2 orders of magnitude faster than conventional techniques. Furthermore, we utilize our platform to analyze oligomer ζ-potential and probe the immunochemistry of wild-type α-synuclein oligomers. Our findings contribute to an improved characterization of α-synuclein oligomers and demonstrate the application of microchip electrophoresis for the free-solution analysis of biological nanoparticle analytes.
Collapse
Affiliation(s)
- William E. Arter
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW UK
- Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE, UK
| | - Catherine K. Xu
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW UK
| | - Marta Castellana-Cruz
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW UK
| | - Therese W. Herling
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW UK
| | - Georg Krainer
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW UK
| | - Kadi L. Saar
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW UK
| | - Janet R. Kumita
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW UK
| | - Christopher M. Dobson
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW UK
| | - Tuomas P. J. Knowles
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW UK
- Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE, UK
| |
Collapse
|
15
|
Seo M, Park S, Lee D, Lee H, Kim SJ. Continuous and spontaneous nanoparticle separation by diffusiophoresis. LAB ON A CHIP 2020; 20:4118-4127. [PMID: 32909576 DOI: 10.1039/d0lc00593b] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The separation of nanoparticles has drawn critical attention in various microfluidic applications including chemical analysis, diagnostics and environmental monitoring. Thus, a number of nanoparticle separation methods have been extensively proposed. However, most of the conventional methods require complicated structured devices, expensive manufacturing processes, and external power sources. While a spontaneous diffusiophoretic separation device based on an ion exchange mechanism could overcome such drawbacks, the recovery of separated particles and the inevitable development of an acidic environment due to the release of H+ from the cation exchange membrane limit its practical applicability. Therefore, in this work, we present a simple but robust nanoparticle separation method based on spontaneously induced diffusiophoresis, which is operated in a continuous manner to overcome the limitations of conventional methods. First, we confirmed that the particle exclusion distance followed the previously developed scaling law of diffusiophoresis. Consequently, we demonstrated the separation of nanoparticles of 40 nm, 200 nm and 2 μm diameter by utilizing the fact that the exclusion distances of various particles were proportional to their diffusiophoretic mobility. Furthermore, the use of Tris buffer increased the diffusiophoretic migration of nanoparticles due to the enhanced concentration gradient, and enabled the produced solution to be compatible with pH-sensitive bio-samples. Therefore, we expect this continuous and spontaneous diffusiophoretic separation platform to be useful in practical applications for analyzing various nano-meter scale bio-particles.
Collapse
Affiliation(s)
- Myungjin Seo
- Department of Electrical and Computer Engineering, Seoul National University, Seoul 08826, Republic of Korea.
| | - Sungmin Park
- Department of Electrical and Computer Engineering, Seoul National University, Seoul 08826, Republic of Korea.
| | - Dokeun Lee
- Department of Electrical and Computer Engineering, Seoul National University, Seoul 08826, Republic of Korea.
| | - Hyomin Lee
- Department of Chemical and Biological Engineering, Jeju National University, Jeju 63243, Republic of Korea.
| | - Sung Jae Kim
- Department of Electrical and Computer Engineering, Seoul National University, Seoul 08826, Republic of Korea. and Nano Systems Institute, Seoul National University, Seoul 08826, Republic of Korea and Inter-university Semiconductor Research Center, Seoul National University, Seoul 08826, Republic of Korea
| |
Collapse
|
16
|
Scheidt T, Kartanas T, Peter Q, Schneider MM, Saar KL, Müller T, Challa PK, Levin A, Devenish S, Knowles TPJ. Multidimensional protein characterisation using microfluidic post-column analysis. LAB ON A CHIP 2020; 20:2663-2673. [PMID: 32588855 DOI: 10.1039/d0lc00219d] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The biological function of proteins is dictated by the formation of supra-molecular complexes that act as the basic machinery of the cell. As such, measuring the properties of protein species in heterogeneous mixtures is of key importance for understanding the molecular basis of biological function. Here, we describe the combination of analytical microfluidic tools with liquid chromatography for multidimensional characterisation of biomolecules in complex mixtures in the solution phase. Following chromatographic separation, a small fraction of the flow-through is distributed to multiple microfluidic devices for analysis. The microfluidic device developed here allows the simultaneous determination of the hydrodynamic radius, electrophoretic mobility, effective molecular charge and isoelectric point of isolated protein species. We demonstrate the operation principle of this approach with a mixture of three unlabelled model proteins varying in size and charge. We further extend the analytical potential of the presented approach by analysing a mixture of interacting streptavidin with biotinylated BSA and fluorophores, which form a mixture of stable complexes with diverse biophysical properties and stoichiometries. The presented microfluidic device positioned in-line with liquid chromatography presents an advanced tool for characterising multidimensional physical properties of proteins in biological samples to further understand the assembly/disassembly mechanism of proteins and the nature of complex mixtures.
Collapse
Affiliation(s)
- Tom Scheidt
- Centre for Misfolding Diseases, Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Wei J. Simulation of diffusio-phoretic motion of colloidal particle suppressed by bound solutes within adsorption shell. Mol Phys 2020. [DOI: 10.1080/00268976.2020.1718226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Jiachen Wei
- Institute of Mechanics, Chinese Academy of Sciences, Beijing, People's Republic of China
- Department of Chemistry, University of Cambridge, Cambridge, UK
| |
Collapse
|
18
|
Wei J, Ramírez-Hinestrosa S, Dobnikar J, Frenkel D. Effect of the interaction strength and anisotropy on the diffusio-phoresis of spherical colloids. SOFT MATTER 2020; 16:3621-3627. [PMID: 32101215 DOI: 10.1039/c9sm02053e] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Gradients in temperature, concentration or electrostatic potential cannot exert forces on a bulk fluid; they can, however, exert forces on a fluid in a microscopic boundary layer surrounding a (nano)colloidal solute, resulting in so-called phoretic flow. Here we present a simulation study of phoretic flow around a spherical colloid held fixed in a concentration gradient. We show that the resulting flow velocity depends non-monotonically on the strength of the colloid-fluid interaction. The reason for this non-monotonic dependence is that solute particles are effectively trapped in a shell around the colloid and cannot contribute to diffusio-phoresis. We also observe that the flow depends sensitively on the anisotropy of solute-colloid interaction.
Collapse
Affiliation(s)
- Jiachen Wei
- Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China and Department of Chemistry, University of Cambridge, CB21EW Cambridge, UK.
| | | | - Jure Dobnikar
- Department of Chemistry, University of Cambridge, CB21EW Cambridge, UK. and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China and Songshan Lake Materials Laboratory, Dongguan 523808, China
| | - Daan Frenkel
- Department of Chemistry, University of Cambridge, CB21EW Cambridge, UK.
| |
Collapse
|
19
|
Arter WE, Levin A, Krainer G, Knowles TPJ. Microfluidic approaches for the analysis of protein-protein interactions in solution. Biophys Rev 2020; 12:575-585. [PMID: 32266673 PMCID: PMC7242286 DOI: 10.1007/s12551-020-00679-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Accepted: 03/02/2020] [Indexed: 12/15/2022] Open
Abstract
Exploration and characterisation of the human proteome is a key objective enabling a heightened understanding of biological function, malfunction and pharmaceutical design. Since proteins typically exhibit their behaviour by binding to other proteins, the challenge of probing protein-protein interactions has been the focus of new and improved experimental approaches. Here, we review recently developed microfluidic techniques for the study and quantification of protein-protein interactions. We focus on methodologies that utilise the inherent strength of microfluidics for the control of mass transport on the micron scale, to facilitate surface and membrane-free interrogation and quantification of interacting proteins. Thus, the microfluidic tools described here provide the capability to yield insights on protein-protein interactions under physiological conditions. We first discuss the defining principles of microfluidics, and methods for the analysis of protein-protein interactions that utilise the diffusion-controlled mixing characteristic of fluids at the microscale. We then describe techniques that employ electrophoretic forces to manipulate and fractionate interacting protein systems for their biophysical characterisation, before discussing strategies that use microdroplet compartmentalisation for the analysis of protein interactions. We conclude by highlighting future directions for the field, such as the integration of microfluidic experiments into high-throughput workflows for the investigation of protein interaction networks.
Collapse
Affiliation(s)
- William E Arter
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
- Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge, CB3 0HE, UK
| | - Aviad Levin
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
| | - Georg Krainer
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
| | - Tuomas P J Knowles
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK.
- Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge, CB3 0HE, UK.
| |
Collapse
|
20
|
Rho HS, Veltkamp HW, Hanke AT, Ottens M, Breukers C, Habibović P, Gardeniers H. Systematic Investigation of Insulin Fibrillation on a Chip. Molecules 2020; 25:molecules25061380. [PMID: 32197443 PMCID: PMC7144930 DOI: 10.3390/molecules25061380] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Revised: 03/13/2020] [Accepted: 03/17/2020] [Indexed: 12/29/2022] Open
Abstract
A microfluidic protein aggregation device (microPAD) that allows the user to perform a series of protein incubations with various concentrations of two reagents is demonstrated. The microfluidic device consists of 64 incubation chambers to perform individual incubations of the protein at 64 specific conditions. Parallel processes of metering reagents, stepwise concentration gradient generation, and mixing are achieved simultaneously by pneumatic valves. Fibrillation of bovine insulin was selected to test the device. The effect of insulin and sodium chloride (NaCl) concentration on the formation of fibrillar structures was studied by observing the growth rate of partially folded protein, using the fluorescent marker Thioflavin-T. Moreover, dual gradients of different NaCl and hydrochloric acid (HCl) concentrations were formed, to investigate their interactive roles in the formation of insulin fibrils and spherulites. The chip-system provides a bird’s eye view on protein aggregation, including an overview of the factors that affect the process and their interactions. This microfluidic platform is potentially useful for rapid analysis of the fibrillation of proteins associated with many misfolding-based diseases, such as quantitative and qualitative studies on amyloid growth.
Collapse
Affiliation(s)
- Hoon Suk Rho
- Department of Instructive Biomaterials Engineering, MERLN Institute for Technology-Inspired Regenerative Medicine, Maastricht University, 6200 MD Maastricht, The Netherlands; (H.S.R.); (P.H.)
- Mesoscale Chemical Systems Group, MESA+ Institute for Nanotechnology, University of Twente, 7522 NB Enschede, The Netherlands
| | - Henk-Willem Veltkamp
- Integrated Devices and Systems Group, MESA+ Institute for Nanotechnology, University of Twente, 7522 NB Enschede, The Netherlands;
| | - Alexander Thomas Hanke
- BioProcess Engineering Group, Department of Biotechnology, Faculty of Applied Sciences, Delft University of Technology, 2628 CD Delft, The Netherlands; (A.T.H.); (M.O.)
| | - Marcel Ottens
- BioProcess Engineering Group, Department of Biotechnology, Faculty of Applied Sciences, Delft University of Technology, 2628 CD Delft, The Netherlands; (A.T.H.); (M.O.)
| | - Christian Breukers
- Medical Cell BioPhysics Group, Technical Medical Centre, University of Twente, 7522 NB Enschede, The Netherlands;
| | - Pamela Habibović
- Department of Instructive Biomaterials Engineering, MERLN Institute for Technology-Inspired Regenerative Medicine, Maastricht University, 6200 MD Maastricht, The Netherlands; (H.S.R.); (P.H.)
| | - Han Gardeniers
- Mesoscale Chemical Systems Group, MESA+ Institute for Nanotechnology, University of Twente, 7522 NB Enschede, The Netherlands
- Correspondence: ; Tel.: +31-(0)53-489-4356
| |
Collapse
|
21
|
Ivanov NA, Kochmann S, Krylov SN. Visualization of Streams of Small Organic Molecules in Continuous-Flow Electrophoresis. Anal Chem 2020; 92:2907-2910. [PMID: 31986876 DOI: 10.1021/acs.analchem.9b05734] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Continuous-flow electrophoresis (CFE) separates a stream of a multicomponent mixture into multiple streams of individual components inside a thin rectangular chamber. CFE will be able to benefit flow chemistry when it is both compatible with nonaqueous solvents utilized in organic synthesis and capable of generically detecting streams of small organic molecules. While stable nonaqueous CFE has been demonstrated, generically detecting molecular streams has not been achieved yet. Here we propose a general approach for molecular stream visualization in CFE via analyte-caused obstruction of excitation of a fluorescent layer underneath the separation chamber-fluorescent sublayer-based visualization (FSV). The concept of FSC-based visualization has been adapted from visualization of small organic molecules on fluorescent plates in thin-layer chromatography. We designed and fabricated a CFE device with one side made of quartz and another side made of UV-absorbing visibly fluorescent, chemically inert, machinable plastic. This device was demonstrated to support nonaqueous CFE of small organic molecules and quantitative detection of their streams in real-time with a limit of detection below 100 μM. Thus, CFE may satisfy conditions required for its seamless integration with continuous flow organic synthesis in flow chemistry.
Collapse
Affiliation(s)
- Nikita A Ivanov
- Department of Chemistry and Centre for Research on Biomolecular Interactions , York University , Toronto , Ontario M3J 1P3 , Canada
| | - Sven Kochmann
- Department of Chemistry and Centre for Research on Biomolecular Interactions , York University , Toronto , Ontario M3J 1P3 , Canada
| | - Sergey N Krylov
- Department of Chemistry and Centre for Research on Biomolecular Interactions , York University , Toronto , Ontario M3J 1P3 , Canada
| |
Collapse
|
22
|
Kristoff CJ, Bwanali L, Veltri LM, Gautam GP, Rutto PK, Newton EO, Holland LA. Challenging Bioanalyses with Capillary Electrophoresis. Anal Chem 2020; 92:49-66. [PMID: 31698907 PMCID: PMC6995690 DOI: 10.1021/acs.analchem.9b04718] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Courtney J. Kristoff
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States
| | - Lloyd Bwanali
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States
| | - Lindsay M. Veltri
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States
| | - Gayatri P. Gautam
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States
| | - Patrick K. Rutto
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States
| | - Ebenezer O. Newton
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States
| | - Lisa A. Holland
- C. Eugene Bennett Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, United States
| |
Collapse
|
23
|
Wright MA, Ruggeri FS, Saar KL, Challa PK, Benesch JLP, Knowles TPJ. Analysis of αB-crystallin polydispersity in solution through native microfluidic electrophoresis. Analyst 2019; 144:4413-4424. [PMID: 31215547 DOI: 10.1039/c9an00382g] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In recent years, significant advancements have been made in the understanding of the population distributions and dynamic oligomeric states of the molecular chaperone αB-crystallin and its core domain variants. In this work, we provide solution-phase evidence of the polydispersity of αB-crystallin using microfluidic methods, used for separating the oligomeric species present in solution according to their different electrophoretic mobilities on-chip in a matter of seconds. We in particular demonstrate that microfluidic high-field electrophoresis and diffusion can detect the oligomerisation of these highly dynamic molecular chaperones and characterise the dominant oligomeric species present. We thereby provide a robust microfluidic method for characterising the individual species within complex protein mixtures of biological relevance.
Collapse
Affiliation(s)
- Maya A Wright
- Department of Chemistry, University of Cambridge, Lensfield Road, CB2 1EW, UK. and Fluidic Analytics Ltd., Unit 5 Chesterton Mill, French's Road CB4 3NP, UK
| | | | - Kadi L Saar
- Department of Chemistry, University of Cambridge, Lensfield Road, CB2 1EW, UK.
| | - Pavan K Challa
- Department of Chemistry, University of Cambridge, Lensfield Road, CB2 1EW, UK.
| | - Justin L P Benesch
- Department of Physical and Theoretical Chemistry, University of Oxford, UK
| | - Tuomas P J Knowles
- Department of Chemistry, University of Cambridge, Lensfield Road, CB2 1EW, UK. and Department of Physics, University of Cambridge, JJ Thomson Ave, Cambridge CB3 0HE, UK
| |
Collapse
|
24
|
Rudisch BM, Pfeiffer SA, Geissler D, Speckmeier E, Robitzki AA, Zeitler K, Belder D. Nonaqueous Micro Free-Flow Electrophoresis for Continuous Separation of Reaction Mixtures in Organic Media. Anal Chem 2019; 91:6689-6694. [DOI: 10.1021/acs.analchem.9b00714] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Benjamin M. Rudisch
- Institute of Analytical Chemistry, Leipzig University, Johannisallee 29, Leipzig 04103, Germany
| | - Simon A. Pfeiffer
- Institute of Analytical Chemistry, Leipzig University, Johannisallee 29, Leipzig 04103, Germany
| | - David Geissler
- Institute of Analytical Chemistry, Leipzig University, Johannisallee 29, Leipzig 04103, Germany
| | - Elisabeth Speckmeier
- Institute of Organic Chemistry, Leipzig University, Johannisallee 29, Leipzig 04103, Germany
| | - Andrea A. Robitzki
- Center for Biotechnology and Biomedicine, Leipzig University, Deutscher Platz 5, Leipzig 04103, Germany
| | - Kirsten Zeitler
- Institute of Organic Chemistry, Leipzig University, Johannisallee 29, Leipzig 04103, Germany
| | - Detlev Belder
- Institute of Analytical Chemistry, Leipzig University, Johannisallee 29, Leipzig 04103, Germany
| |
Collapse
|
25
|
Matos MJ, Navo CD, Hakala T, Ferhati X, Guerreiro A, Hartmann D, Bernardim B, Saar KL, Compañón I, Corzana F, Knowles TPJ, Jiménez‐Osés G, Bernardes GJL. Quaternization of Vinyl/Alkynyl Pyridine Enables Ultrafast Cysteine‐Selective Protein Modification and Charge Modulation. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201901405] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Maria J. Matos
- Department of ChemistryUniversity of Cambridge Lensfield Road CB2 1EW Cambridge UK
| | - Claudio D. Navo
- Departamento de QuímicaUniversidad de La RiojaCentro de Investigación en Síntesis Química 26006 Logroño Spain
- CIC bioGUNEBizkaia Technology Park Building 801A 48170 Derio Spain
| | - Tuuli Hakala
- Department of ChemistryUniversity of Cambridge Lensfield Road CB2 1EW Cambridge UK
| | - Xhenti Ferhati
- Departamento de QuímicaUniversidad de La RiojaCentro de Investigación en Síntesis Química 26006 Logroño Spain
| | - Ana Guerreiro
- Instituto de Medicina Molecular, Faculdade de MedicinaUniversidade de Lisboa Avenida Professor Egas Moniz 1649-028 Lisboa Portugal
| | - David Hartmann
- Department of ChemistryUniversity of Cambridge Lensfield Road CB2 1EW Cambridge UK
| | - Barbara Bernardim
- Department of ChemistryUniversity of Cambridge Lensfield Road CB2 1EW Cambridge UK
| | - Kadi L. Saar
- Department of ChemistryUniversity of Cambridge Lensfield Road CB2 1EW Cambridge UK
| | - Ismael Compañón
- Departamento de QuímicaUniversidad de La RiojaCentro de Investigación en Síntesis Química 26006 Logroño Spain
| | - Francisco Corzana
- Departamento de QuímicaUniversidad de La RiojaCentro de Investigación en Síntesis Química 26006 Logroño Spain
| | - Tuomas P. J. Knowles
- Department of ChemistryUniversity of Cambridge Lensfield Road CB2 1EW Cambridge UK
| | - Gonzalo Jiménez‐Osés
- Departamento de QuímicaUniversidad de La RiojaCentro de Investigación en Síntesis Química 26006 Logroño Spain
- CIC bioGUNEBizkaia Technology Park Building 801A 48170 Derio Spain
| | - Gonçalo J. L. Bernardes
- Department of ChemistryUniversity of Cambridge Lensfield Road CB2 1EW Cambridge UK
- Instituto de Medicina Molecular, Faculdade de MedicinaUniversidade de Lisboa Avenida Professor Egas Moniz 1649-028 Lisboa Portugal
| |
Collapse
|
26
|
Matos MJ, Navo CD, Hakala T, Ferhati X, Guerreiro A, Hartmann D, Bernardim B, Saar KL, Compañón I, Corzana F, Knowles TPJ, Jiménez-Osés G, Bernardes GJL. Quaternization of Vinyl/Alkynyl Pyridine Enables Ultrafast Cysteine-Selective Protein Modification and Charge Modulation. Angew Chem Int Ed Engl 2019; 58:6640-6644. [PMID: 30897271 PMCID: PMC6618083 DOI: 10.1002/anie.201901405] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 03/11/2019] [Indexed: 12/31/2022]
Abstract
Quaternized vinyl‐ and alkynyl‐pyridine reagents were shown to react in an ultrafast and selective manner with several cysteine‐tagged proteins at near‐stoichiometric quantities. We have demonstrated that this method can effectively create a homogenous antibody–drug conjugate that features a precise drug‐to‐antibody ratio of 2, which was stable in human plasma and retained its specificity towards Her2+ cells. Finally, the developed warhead introduces a +1 charge to the overall net charge of the protein, which enabled us to show that the electrophoretic mobility of the protein may be tuned through the simple attachment of a quaternized vinyl pyridinium reagent at the cysteine residues. We anticipate the generalized use of quaternized vinyl‐ and alkynyl‐pyridine reagents not only for bioconjugation, but also as warheads for covalent inhibition and as tools to profile cysteine reactivity.
Collapse
Affiliation(s)
- Maria J Matos
- Department of Chemistry, University of Cambridge, Lensfield Road, CB2 1EW, Cambridge, UK
| | - Claudio D Navo
- Departamento de Química, Universidad de La Rioja, Centro de Investigación en Síntesis Química, 26006, Logroño, Spain.,CIC bioGUNE, Bizkaia Technology Park, Building 801A, 48170, Derio, Spain
| | - Tuuli Hakala
- Department of Chemistry, University of Cambridge, Lensfield Road, CB2 1EW, Cambridge, UK
| | - Xhenti Ferhati
- Departamento de Química, Universidad de La Rioja, Centro de Investigación en Síntesis Química, 26006, Logroño, Spain
| | - Ana Guerreiro
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Avenida Professor Egas Moniz, 1649-028, Lisboa, Portugal
| | - David Hartmann
- Department of Chemistry, University of Cambridge, Lensfield Road, CB2 1EW, Cambridge, UK
| | - Barbara Bernardim
- Department of Chemistry, University of Cambridge, Lensfield Road, CB2 1EW, Cambridge, UK
| | - Kadi L Saar
- Department of Chemistry, University of Cambridge, Lensfield Road, CB2 1EW, Cambridge, UK
| | - Ismael Compañón
- Departamento de Química, Universidad de La Rioja, Centro de Investigación en Síntesis Química, 26006, Logroño, Spain
| | - Francisco Corzana
- Departamento de Química, Universidad de La Rioja, Centro de Investigación en Síntesis Química, 26006, Logroño, Spain
| | - Tuomas P J Knowles
- Department of Chemistry, University of Cambridge, Lensfield Road, CB2 1EW, Cambridge, UK
| | - Gonzalo Jiménez-Osés
- Departamento de Química, Universidad de La Rioja, Centro de Investigación en Síntesis Química, 26006, Logroño, Spain.,CIC bioGUNE, Bizkaia Technology Park, Building 801A, 48170, Derio, Spain
| | - Gonçalo J L Bernardes
- Department of Chemistry, University of Cambridge, Lensfield Road, CB2 1EW, Cambridge, UK.,Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Avenida Professor Egas Moniz, 1649-028, Lisboa, Portugal
| |
Collapse
|
27
|
Vanderpoorten O, Peter Q, Challa PK, Keyser UF, Baumberg J, Kaminski CF, Knowles TPJ. Scalable integration of nano-, and microfluidics with hybrid two-photon lithography. MICROSYSTEMS & NANOENGINEERING 2019; 5:40. [PMID: 31636930 PMCID: PMC6799807 DOI: 10.1038/s41378-019-0080-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 05/26/2019] [Accepted: 06/25/2019] [Indexed: 05/19/2023]
Abstract
Nanofluidic devices have great potential for applications in areas ranging from renewable energy to human health. A crucial requirement for the successful operation of nanofluidic devices is the ability to interface them in a scalable manner with the outside world. Here, we demonstrate a hybrid two photon nanolithography approach interfaced with conventional mask whole-wafer UV-photolithography to generate master wafers for the fabrication of integrated micro and nanofluidic devices. Using this approach we demonstrate the fabrication of molds from SU-8 photoresist with nanofluidic features down to 230 nm lateral width and channel heights from micron to sub-100 nm. Scanning electron microscopy and atomic force microscopy were used to characterize the printing capabilities of the system and show the integration of nanofluidic channels into an existing microfluidic chip design. The functionality of the devices was demonstrated through super-resolution microscopy, allowing the observation of features below the diffraction limit of light produced using our approach. Single molecule localization of diffusing dye molecules verified the successful imprint of nanochannels and the spatial confinement of molecules to 200 nm across the nanochannel molded from the master wafer. This approach integrates readily with current microfluidic fabrication methods and allows the combination of microfluidic devices with locally two-photon-written nano-sized functionalities, enabling rapid nanofluidic device fabrication and enhancement of existing microfluidic device architectures with nanofluidic features.
Collapse
Affiliation(s)
- Oliver Vanderpoorten
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge, CB3 0AS UK
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW UK
- Cavendish Laboratory, Department of Physics, University of Cambridge, J. J. Thomson Avenue, Cambridge, CB30HE UK
| | - Quentin Peter
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW UK
| | - Pavan K. Challa
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW UK
| | - Ulrich F. Keyser
- Cavendish Laboratory, Department of Physics, University of Cambridge, J. J. Thomson Avenue, Cambridge, CB30HE UK
| | - Jeremy Baumberg
- Cavendish Laboratory, Department of Physics, University of Cambridge, J. J. Thomson Avenue, Cambridge, CB30HE UK
| | - Clemens F. Kaminski
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Philippa Fawcett Drive, Cambridge, CB3 0AS UK
| | - Tuomas P. J. Knowles
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW UK
- Cavendish Laboratory, Department of Physics, University of Cambridge, J. J. Thomson Avenue, Cambridge, CB30HE UK
| |
Collapse
|
28
|
Saar KL, Peter Q, Müller T, Challa PK, Herling TW, Knowles TPJ. Rapid two-dimensional characterisation of proteins in solution. MICROSYSTEMS & NANOENGINEERING 2019; 5:33. [PMID: 31636924 PMCID: PMC6799820 DOI: 10.1038/s41378-019-0072-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 02/25/2019] [Accepted: 03/21/2019] [Indexed: 05/20/2023]
Abstract
Microfluidic platforms provide an excellent basis for working with heterogeneous samples and separating biomolecular components at high throughput, with high recovery rates and by using only very small sample volumes. To date, several micron scale platforms with preparative capabilities have been demonstrated. Here we describe and demonstrate a microfluidic device that brings preparative and analytical operations together onto a single chip and thereby allows the acquisition of multidimensional information. We achieve this objective by using a free-flow electrophoretic separation approach that directs fractions of sample into an on-chip analysis unit, where the fractions are characterised through a microfluidic diffusional sizing process. This combined approach therefore allows simultaneously quantifying the sizes and the charges of components in heterogenous mixtures. We illustrate the power of the platform by describing the size distribution of a mixture comprising components which are close in size and cannot be identified as individual components using state-of-the-art solution sizing techniques on their own. Furthermore, we show that the platform can be used for two-dimensional fingerprinting of heterogeneous protein mixtures within tens of seconds, opening up a possibility to obtain multiparameter data on biomolecular systems on a minute timescale.
Collapse
Affiliation(s)
- Kadi L. Saar
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW UK
| | - Quentin Peter
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW UK
- Cavendish Laboratory, Department of Physics, University of Cambridge, J J Thomson Ave, Cambridge, CB3 0HE UK
| | | | - Pavan K. Challa
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW UK
- Cavendish Laboratory, Department of Physics, University of Cambridge, J J Thomson Ave, Cambridge, CB3 0HE UK
| | - Therese W. Herling
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW UK
| | - Tuomas P. J. Knowles
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW UK
- Cavendish Laboratory, Department of Physics, University of Cambridge, J J Thomson Ave, Cambridge, CB3 0HE UK
| |
Collapse
|
29
|
Arter WE, Charmet J, Kong J, Saar KL, Herling TW, Müller T, Keyser UF, Knowles TPJ. Combining Affinity Selection and Specific Ion Mobility for Microchip Protein Sensing. Anal Chem 2018; 90:10302-10310. [PMID: 30070105 DOI: 10.1021/acs.analchem.8b02051] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The sensitive detection of proteins is a key objective in many areas of biomolecular science, ranging from biophysics to diagnostics. However, sensing in complex biological fluids is hindered by nonspecific interactions with off-target species. Here, we describe and demonstrate an assay that utilizes both the chemical and physical properties of the target species to achieve high selectivity in a manner not possible by chemical complementarity alone, in complex media. We achieve this objective through a combinatorial strategy, by simultaneously exploiting free-flow electrophoresis for target selection, on the basis of electrophoretic mobility, and conventional affinity-based selection. In addition, we demonstrate amplification of the resultant signal by a catalytic DNA nanocircuit. This approach brings together the inherent solution-phase advantages of microfluidic sample handling with isothermal, enzyme-free signal amplification. With this method, no surface immobilization or washing steps are required, and our assay is well suited to monoepitopic targets, presenting advantages over conventional ELISA techniques.
Collapse
Affiliation(s)
- William E Arter
- Cavendish Laboratory , University of Cambridge , JJ Thomson Avenue , Cambridge CB3 0HE , U.K.,Department of Chemistry , University of Cambridge , Lensfield Road , Cambridge CB2 1EW , U.K
| | - Jérôme Charmet
- Department of Chemistry , University of Cambridge , Lensfield Road , Cambridge CB2 1EW , U.K.,Institute of Digital Healthcare, International Digital Laboratory, WMG , University of Warwick , Coventry CV4 7AL , U.K
| | - Jinglin Kong
- Cavendish Laboratory , University of Cambridge , JJ Thomson Avenue , Cambridge CB3 0HE , U.K
| | - Kadi L Saar
- Department of Chemistry , University of Cambridge , Lensfield Road , Cambridge CB2 1EW , U.K
| | - Therese W Herling
- Department of Chemistry , University of Cambridge , Lensfield Road , Cambridge CB2 1EW , U.K
| | | | - Ulrich F Keyser
- Cavendish Laboratory , University of Cambridge , JJ Thomson Avenue , Cambridge CB3 0HE , U.K
| | - Tuomas P J Knowles
- Cavendish Laboratory , University of Cambridge , JJ Thomson Avenue , Cambridge CB3 0HE , U.K.,Department of Chemistry , University of Cambridge , Lensfield Road , Cambridge CB2 1EW , U.K
| |
Collapse
|
30
|
Saar KL, Müller T, Charmet J, Challa PK, Knowles TPJ. Enhancing the Resolution of Micro Free Flow Electrophoresis through Spatially Controlled Sample Injection. Anal Chem 2018; 90:8998-9005. [PMID: 29938505 DOI: 10.1021/acs.analchem.8b01205] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Free flow electrophoresis is a versatile technique for the continuous separation of mixtures with both preparative and analytical applications. Microscale versions of free flow electrophoresis are particularly attractive strategies because of their fast separation times, ability to work with small sample volumes, and large surface area to volume ratios facilitating rapid heat transfer, thus minimizing the detrimental effects of Joule heating even at high voltages. The resolution of microscale free flow electrophoresis, however, is limited by the broadening of the analyte beam in the microfluidic channel, an effect that becomes especially pronounced when the analyte is deflected significantly away from its original position. Here, we describe and demonstrate how restricting spatially the sample injection and collection to the regions where the gradients in the velocity distribution of the carrier medium are the smallest allows this broadening effect to be substantially suppressed and hence the resolution of microscale free flow electrophoresis devices to be increased. To demonstrate this concept, we fabricated microfluidic free flow electrophoresis devices with spatially restricted injection nozzles implemented through the use of multilayer soft-photolithography and further integrated quartz based observation areas for fluorescent detection and imaging. With these devices, we demonstrated a 5-fold reduction in the extent of beam broadening relative to conventional free flow electrophoresis approaches with nonrestricted sample introduction. The manifold enhancement in the achievable resolution of microscale free flow electrophoresis devices opens up the possibility of rapid separation and analysis of complex mixtures.
Collapse
Affiliation(s)
- Kadi L Saar
- Department of Chemistry , University of Cambridge , Lensfield Road , Cambridge CB2 1EW , United Kingdom
| | - Thomas Müller
- Fluidic Analytics Limited , Unit 5 Chesterton Mill, French's Road , Cambridge CB4 3NP , United Kingdom
| | - Jérôme Charmet
- Institute of Digital Healthcare, WMG , University of Warwick , Coventry CV4 7AL , United Kingdom
| | - Pavan Kumar Challa
- Department of Chemistry , University of Cambridge , Lensfield Road , Cambridge CB2 1EW , United Kingdom
| | - Tuomas P J Knowles
- Department of Chemistry , University of Cambridge , Lensfield Road , Cambridge CB2 1EW , United Kingdom.,Cavendish Laboratory, Department of Physics , University of Cambridge , J J Thomson Avenue , Cambridge CB3 0HE , United Kingdom
| |
Collapse
|