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Ray S, Buell AK. Emerging experimental methods to study the thermodynamics of biomolecular condensate formation. J Chem Phys 2024; 160:091001. [PMID: 38445729 DOI: 10.1063/5.0190160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Accepted: 02/15/2024] [Indexed: 03/07/2024] Open
Abstract
The formation of biomolecular condensates in vivo is increasingly recognized to underlie a multitude of crucial cellular functions. Furthermore, the evolution of highly dynamic protein condensates into progressively less reversible assemblies is thought to be involved in a variety of disorders, from cancer over neurodegeneration to rare genetic disorders. There is an increasing need for efficient experimental methods to characterize the thermodynamics of condensate formation and that can be used in screening campaigns to identify and rationally design condensate modifying compounds. Theoretical advances in the field are also identifying the key parameters that need to be measured in order to obtain a comprehensive understanding of the underlying interactions and driving forces. Here, we review recent progress in the development of efficient and quantitative experimental methods to study the driving forces behind and the temporal evolution of biomolecular condensates.
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Affiliation(s)
- Soumik Ray
- Department of Biotechnology and Biomedicine, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - Alexander K Buell
- Department of Biotechnology and Biomedicine, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
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2
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Li Y, Li D, Zhao P, Nandakumar K, Wang L, Song Y. Microfluidics-Based Systems in Diagnosis of Alzheimer's Disease and Biomimetic Modeling. MICROMACHINES 2020; 11:mi11090787. [PMID: 32825153 PMCID: PMC7569794 DOI: 10.3390/mi11090787] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 08/13/2020] [Accepted: 08/13/2020] [Indexed: 12/21/2022]
Abstract
Early detection and accurate diagnosis of Alzheimer’s disease (AD) is essential for patient care and disease treatment. Microfluidic technology is emerging as an economical and versatile platform in disease detection and diagnosis. It can be conveniently integrated with nanotechnology and/or biological models for biomedical functional and pre-clinical treatment study. These strengths make it advantageous in disease biomarker detection and functional analysis against a wide range of biological backgrounds. This review highlights the recent developments and trends of microfluidic applications in AD research. The first part looks at the principles and methods for AD diagnostic biomarker detection and profiling. The second part discusses how microfluidic chips, especially organ-on-a-chip platforms, could be used as an independent approach and/or integrated with other technologies in AD biomimetic functional analysis.
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Affiliation(s)
- Yan Li
- Energy Institute, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250014, China; (Y.L.); (P.Z.); (K.N.)
- School of Energy and Power Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250014, China
| | - Danni Li
- Department of Neurology, Jinan Central Hospital, Cheeloo College of Medicine, Shandong University, Jinan 250013, China;
| | - Pei Zhao
- Energy Institute, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250014, China; (Y.L.); (P.Z.); (K.N.)
- School of Energy and Power Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250014, China
| | - Krishnaswamy Nandakumar
- Energy Institute, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250014, China; (Y.L.); (P.Z.); (K.N.)
- Cain Department of Chemical Engineering, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Liqiu Wang
- Department of Mechanical Engineering, Faculty of Engineering, The University of Hong Kong, Hong Kong, China
- Correspondence: (L.W.); (Y.S.)
| | - Youqiang Song
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong, China
- State Key Laboratory for Cognitive and Brain Sciences, The University of Hong Kong, Hong Kong, China
- Correspondence: (L.W.); (Y.S.)
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3
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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.
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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
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4
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Abstract
Single-cell analysis serves as an important approach to study cell functions and interactions. Catering to the demand of Big Data Era, fast reactions for single cells and paralleled high-throughput analysis have become an urgent need. Microdroplet in microfluidics has advantages of modularity and integrity, as well as high throughput and sensitivity, which present great potential in the field of single-cell analysis. This review is carried out on three aspects to introduce microdroplet chips for single-cell analysis: droplet formation, droplet detection and practical functions. Structures of droplet formation are categorized into three types, including T-shaped channel, flow-involved channel and three-dimensional micro-vortice. The detection methods, including fluorescence, Raman spectroscopy, mass spectroscopy and electrochemical detection, are summarized from applications. Both pros and cons for existing techniques are reviewed and discussed. The functions of microdroplets-on-chip cover cell culture, nucleic acid test and cell identification. For each field, principles/mechanisms and/or schematic images are laconically introduced. Microdroplet in microfluidics has become a major research direction in single-cell analysis. With updated methods of droplet formation such as inertial ordering and micro-vortice, microdroplets-based biochips will expect high throughput detection and high-accuracy trace detection for clinical diagnosis in the near future.
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Affiliation(s)
- Aihui Wang
- 1 Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, China.,2 State Key Laboratory of Oncogenes and Related Genes, Institute for Personalized Medicine, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China.,3 School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Aynur Abdulla
- 1 Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, China.,2 State Key Laboratory of Oncogenes and Related Genes, Institute for Personalized Medicine, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Xianting Ding
- 1 Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, China.,2 State Key Laboratory of Oncogenes and Related Genes, Institute for Personalized Medicine, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
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5
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Yu Y, Wang P, Zhu X, Peng Q, Zhou Y, Yin T, Liang Y, Yin X. Combined determination of copper ions and β-amyloid peptide by a single ratiometric electrochemical biosensor. Analyst 2018; 143:323-331. [PMID: 29192910 DOI: 10.1039/c7an01683b] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Copper ions (Cu2+) play a critical role in biological processes and are directly involved in β-amyloid peptide (Aβ) aggregation, which is responsible for the occurrence and development of Alzheimer's disease (AD). Therefore, combined determination of Cu2+ and Aβ in one analytical system is of great significance to understand the exact nature of the AD event. This work presents a novel ratiometric electrochemical biosensor for the dual determination of Cu2+ and Aβ1-42. This unique sensor is based on a 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulphonate) (ABTS) and poly(diallyldimethylammonium chloride) (PDDA)-bi functionalized single-walled carbon nanotubes (ABTS-PDDA/CNTs) composite. The inclusion of ABTS not only enhanced the sensitivity, but it also acted as an inner reference molecule to improve detection accuracy. The specific recognition of Cu2+ was realized by neurokinin B (NKB) coatings on the ABTS-PDDA/CNTs surface to form a [CuII(NKB)2] complex with Cu2+. The ABTS-PDDA/CNTs-NKB modified electrode also displayed an excellent electrochemical response toward the Aβ1-42 monomer, when a certain amount of the Aβ1-42 monomer was added to Cu2+-contained PBS buffer, which was due to the release of Cu2+ from the [CuII(NKB)2] complex through Aβ binding to Cu2+. Meanwhile, our work showed that Cu2+ bound Aβ1-42 was concentration-dependent. Consequently, the presented electrochemical approach was capable of quantifying two important biological species associated with AD by one single biosensor, with the detection limits of 0.04 μM for Cu2+ and 0.5 ng mL-1 for Aβ1-42, respectively. Finally, the ratiometric electrode was successfully applied for monitoring Cu2+ and Aβ1-42 variations in plasma and hippocampus of normal and AD rats.
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Affiliation(s)
- Yanyan Yu
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Xuzhou Medical University, 209 Tongshan Road, Xuzhou 221004, Jiangsu, P.R. China.
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Zilberzwige-Tal S, Gazit E. Go with the Flow-Microfluidics Approaches for Amyloid Research. Chem Asian J 2018; 13:3437-3447. [PMID: 30117682 DOI: 10.1002/asia.201801007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Indexed: 12/19/2022]
Abstract
The rapid development of cost-efficient microfluidic devices has received tremendous attention from scientists of diverse fields. The growing potential of utilizing microfluidic platforms has further advanced the ability to integrate existing technology into microfluidic devices. Thus, allowing scientists to approach questions in fundamental fields, such as amyloid research, using new and otherwise unachievable conditions. Amyloids are associated with neurodegeneration and are in the forefront of many research efforts worldwide. The newly emerged microfluidic technology can serve as a novel research tool providing a platform for developing new methods in this field. In this review, we summarize the recent progress in amyloid research using microfluidic approaches. These approaches are driven from various fields, including physical chemistry, electrochemistry, biochemistry, and cell biology. Moreover, the new insights into novel microfluidic approaches for amyloid research reviewed here can be easily modified for other research interests.
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Affiliation(s)
- Shai Zilberzwige-Tal
- Department of Molecular Microbiology and Biotechnology, School of Molecular Cell Biology and Biotechnology,George S. Wise Faculty of Life Sciences, Tel Aviv University⋅, Tel Aviv, 69978, Israel
| | - Ehud Gazit
- Department of Materials Science and Engineering, Iby and Aladar Fleischman Faculty of Engineering, Tel Aviv University, Tel Aviv, 69978, Israel.,Department of Molecular Microbiology and Biotechnology, School of Molecular Cell Biology and Biotechnology,George S. Wise Faculty of Life Sciences, Tel Aviv University⋅, Tel Aviv, 69978, Israel
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7
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Buell AK. The Nucleation of Protein Aggregates - From Crystals to Amyloid Fibrils. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2017; 329:187-226. [DOI: 10.1016/bs.ircmb.2016.08.014] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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8
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Karle M, Vashist SK, Zengerle R, von Stetten F. Microfluidic solutions enabling continuous processing and monitoring of biological samples: A review. Anal Chim Acta 2016; 929:1-22. [DOI: 10.1016/j.aca.2016.04.055] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Revised: 04/26/2016] [Accepted: 04/30/2016] [Indexed: 01/25/2023]
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9
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Monitoring microbial metabolites using an inductively coupled resonance circuit. Sci Rep 2015; 5:12878. [PMID: 26264183 PMCID: PMC4533006 DOI: 10.1038/srep12878] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Accepted: 07/13/2015] [Indexed: 12/29/2022] Open
Abstract
We present a new approach to monitor microbial population dynamics in emulsion droplets via changes in metabolite composition, using an inductively coupled LC resonance circuit. The signal measured by such resonance detector provides information on the magnetic field interaction with the bacterial culture, which is complementary to the information accessible by other detection means, based on electric field interaction, i.e. capacitive or resistive, as well as optical techniques. Several charge-related factors, including pH and ammonia concentrations, were identified as possible contributors to the characteristic of resonance detector profile. The setup enables probing the ionic byproducts of microbial metabolic activity at later stages of cell growth, where conventional optical detection methods have no discriminating power.
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Janiesch JW, Weiss M, Kannenberg G, Hannabuss J, Surrey T, Platzman I, Spatz JP. Key factors for stable retention of fluorophores and labeled biomolecules in droplet-based microfluidics. Anal Chem 2015; 87:2063-7. [PMID: 25607822 DOI: 10.1021/ac504736e] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Water-in-oil emulsion droplets created in droplet-based microfluidic devices have been tested and used recently as well-defined picoliter-sized 3D compartments for various biochemical and biomedical applications. In many of these applications, fluorescence measurements are applied to reveal the protein content, spatial distribution, and dynamics in the droplets. However, emulsion droplets do not always provide entirely sealed compartments, and partitioning of dyes or labeled molecules to the oil phase is frequently observed. Therefore, stable molecular retention in the droplets represents a challenge, and many physical and chemical key factors of microfluidic system components have to be considered. In this study, we investigated the retention of 12 commonly used water-soluble dyes in droplets having six different aqueous phase conditions. We demonstrate that the physicochemical properties of the dyes have a major influence on the retention level. In particular, hydrophilicity has a strong influence on retention, with highly hydrophilic dyes (LogD < -7) showing stable, buffer/medium independent retention. In the case of less hydrophilic dyes, we showed that retention can be improved by adjusting the surfactants physical properties, such as geometry, length, and concentration. Furthermore, we analyzed the retention stability of labeled biomolecules such as antibodies, streptavidin, and tubulin proteins and showed that stable retention can be strongly dependent on dye and surfactants selection.
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Affiliation(s)
- Jan-Willi Janiesch
- Department of New Materials and Biosystems, Max Planck Institute for Intelligent Systems , Heisenbergstr. 3, 70569 Stuttgart, Germany
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11
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Saha A, Jana NR. Paper-based microfluidic approach for surface-enhanced raman spectroscopy and highly reproducible detection of proteins beyond picomolar concentration. ACS APPLIED MATERIALS & INTERFACES 2015; 7:996-1003. [PMID: 25521159 DOI: 10.1021/am508123x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Although microfluidic approach is widely used in various point of care diagnostics, its implementation in surface enhanced Raman spectroscopy (SERS)-based detection is challenging. This is because SERS signal depends on plasmonic nanoparticle aggregation induced generation of stable electromagnetic hot spots and in currently available microfluidic platform this condition is difficult to adapt. Here we show that SERS can be adapted using simple paper based microfluidic system where both the plasmonic nanomaterials and analyte are used in mobile phase. This approach allows analyte induced controlled particle aggregation and electromagnetic hot spot generation inside the microfluidic channel with the resultant SERS signal, which is highly reproducible and sensitive. This approach has been used for reproducible detection of protein in the pico to femtomolar concentration. Presented approach is simple, rapid, and cost-effective, and requires low sample volume. Method can be extended for SERS-based detection of other biomolecules.
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Affiliation(s)
- Arindam Saha
- Centre for Advanced Materials, Indian Association for the Cultivation of Science , Kolkata 700032, India
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12
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Zhang L, Wang Y, Tong L, Xia Y. Synthesis of colloidal metal nanocrystals in droplet reactors: the pros and cons of interfacial adsorption. NANO LETTERS 2014; 14:4189-4194. [PMID: 24960241 DOI: 10.1021/nl501994q] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Droplet reactors have received considerable attention in recent years as an alternative route to the synthesis and potentially high-volume production of colloidal metal nanocrystals. Interfacial adsorption will immediately become an important issue to address when one seeks to translate a nanocrystal synthesis from batch reactors to droplet reactors due to the involvement of higher surface-to-volume ratios for the droplets and the fact that nanocrystals tend to be concentrated at the water-oil interface. Here we report a systematic study to compare the pros and cons of interfacial adsorption of metal nanocrystals during their synthesis in droplet reactors. On the one hand, interfacial adsorption can be used to generate nanocrystals with asymmetric shapes or structures, including one-sixth-truncated Ag octahedra and Au-Ag nanocups. On the other hand, interfacial adsorption has to be mitigated to obtain nanocrystals with uniform sizes and controlled shapes. We confirmed that Triton X-100, a nonionic surfactant, could effectively alleviate interfacial adsorption while imposing no impact on the capping agent typically needed for a shape-controlled synthesis. With the introduction of a proper surfactant, droplet reactors offer an attractive platform for the continuous production of colloidal metal nanocrystals.
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Affiliation(s)
- Lei Zhang
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University , Atlanta, Georgia 30332, United States
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13
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Knowles TPJ, Vendruscolo M, Dobson CM. The amyloid state and its association with protein misfolding diseases. Nat Rev Mol Cell Biol 2014; 15:384-96. [PMID: 24854788 DOI: 10.1038/nrm3810] [Citation(s) in RCA: 1584] [Impact Index Per Article: 158.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The phenomenon of protein aggregation and amyloid formation has become the subject of rapidly increasing research activities across a wide range of scientific disciplines. Such activities have been stimulated by the association of amyloid deposition with a range of debilitating medical disorders, from Alzheimer's disease to type II diabetes, many of which are major threats to human health and welfare in the modern world. It has become clear, however, that the ability to form the amyloid state is more general than previously imagined, and that its study can provide unique insights into the nature of the functional forms of peptides and proteins, as well as understanding the means by which protein homeostasis can be maintained and protein metastasis avoided.
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Affiliation(s)
- Tuomas P J Knowles
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK
| | - Michele Vendruscolo
- 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
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14
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Chiu YL, Chan HF, Phua KKL, Zhang Y, Juul S, Knudsen BR, Ho YP, Leong KW. Synthesis of fluorosurfactants for emulsion-based biological applications. ACS NANO 2014; 8:3913-20. [PMID: 24646088 PMCID: PMC4004322 DOI: 10.1021/nn500810n] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/14/2023]
Abstract
Microemulsion represents an attractive platform for fundamental and applied biomedical research because the emulsified droplets can serve as millions of compartmentalized micrometer-sized reactors amenable to high-throughput screening or online monitoring. However, establishing stable emulsions with surfactants that are compatible with biological applications remains a significant challenge. Motivated by the lack of commercially available surfactants suitable for microemulsion-based biological assays, this study describes the facile synthesis of a biocompatible fluorosurfactant with nonionic tris(hydroxymethyl)methyl (Tris) polar head groups. We have further demonstrated compatibility of the developed surfactant with diverse emulsion-based applications, including DNA polymeric nanoparticle synthesis, enzymatic activity assay, and bacterial or mammalian cell culture, in the setup of both double- and multiphases of emulsions.
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Affiliation(s)
- Ya-Ling Chiu
- Department of Biomedical Engineering, Duke University , North Carolina 27708, United States
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15
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Müller T, Ruggeri FS, Kulik AJ, Shimanovich U, Mason TO, Knowles TPJ, Dietler G. Nanoscale spatially resolved infrared spectra from single microdroplets. LAB ON A CHIP 2014; 14:1315-1319. [PMID: 24519414 DOI: 10.1039/c3lc51219c] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Droplet microfluidics has emerged as a powerful platform allowing a large number of individual reactions to be carried out in spatially distinct microcompartments. Due to their small size, however, the spectroscopic characterisation of species encapsulated in such systems remains challenging. In this paper, we demonstrate the acquisition of infrared spectra from single microdroplets containing aggregation-prone proteins. To this effect, droplets are generated in a microfluidic flow-focussing device and subsequently deposited in a square array onto a ZnSe prism using a micro stamp. After drying, the solutes present in the droplets are illuminated locally by an infrared laser through the prism, and their thermal expansion upon absorption of infrared radiation is measured with an atomic force microscopy tip, granting nanoscale resolution. Using this approach, we resolve structural differences in the amide bands of the spectra of monomeric and aggregated lysozyme from single microdroplets with picolitre volume.
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Affiliation(s)
- Thomas Müller
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK.
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16
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Medina-Sánchez M, Miserere S, Morales-Narváez E, Merkoçi A. On-chip magneto-immunoassay for Alzheimer's biomarker electrochemical detection by using quantum dots as labels. Biosens Bioelectron 2014; 54:279-84. [DOI: 10.1016/j.bios.2013.10.069] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Revised: 10/21/2013] [Accepted: 10/23/2013] [Indexed: 12/13/2022]
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17
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Choi I, Lee LP. Rapid detection of Aβ aggregation and inhibition by dual functions of gold nanoplasmic particles: catalytic activator and optical reporter. ACS NANO 2013; 7:6268-6277. [PMID: 23777418 DOI: 10.1021/nn402310c] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
One of the primary pathological hallmarks of Alzheimer's diseases (AD) is amyloid-β (Aβ) aggregation and its extracellular accumulation. However, current in vitro Aβ aggregation assays require time-consuming and labor-intensive steps, which delay the process of drug discovery and understanding the mechanism of Aβ induced neurotoxicity. Here, we propose a rapid detection method for studying Aβ aggregation and inhibition under an optimized acidic perturbation condition by dual functions of gold nanoplasmonic particles (GNPs): (1) catalytic activator and (2) optical reporter. Because of roles of GNPs as effective nucleation sites for fast-catalyzing Aβ aggregation and colorimetric optical reporters for tracking Aβ aggregation, we accomplished the fast aggregation assay in less than 1 min by the naked eyes. Our detection method is based on spontaneous clustering of unconjugated (unmodified) GNPs along with the aggregated Aβ network under an aggregation-promoting condition. As a proof-of-concept demonstration, we employed the acidic perturbation permitting rapid cooperative assemblies of GNPs and Aβ peptides via their surface charge modulation. Under the optimized acidic perturbation condition around pH 2 to 3, we characterized the concentration-dependent colorimetric responses for aggregation at physiologically relevant Aβ concentration levels (from 100 μM to 10 nM). We also demonstrated the GNP/acidic condition-based rapid inhibition assay of Aβ aggregation by using well-known binding reagents such as antibody and serum albumin. The proposed methodology can be a powerful alternative method for screening drugs for AD as well as studying molecular biophysics of protein aggregations, and further extended to explore other protein conformational diseases such as neurodegenerative disease.
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Affiliation(s)
- Inhee Choi
- Berkeley Sensor and Actuator Center, Department of Bioengineering, Department of Electrical Engineering and Computer Science, University of California at Berkeley, Berkeley, California 94720, USA
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Fukuda J, Takahashi S, Osaki T, Mochizuki N, Suzuki H. Processing of nanolitre liquid plugs for microfluidic cell-based assays. SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS 2012; 13:064201. [PMID: 27877528 PMCID: PMC5099761 DOI: 10.1088/1468-6996/13/6/064201] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Accepted: 09/09/2012] [Indexed: 06/06/2023]
Abstract
Plugs, i.e. droplets formed in a microchannel, may revolutionize microfluidic cell-based assays. This study describes a microdevice that handles nanolitre-scale liquid plugs for the preparation of various culture setups and subsequent cellular assays. An important feature of this mode of liquid operation is that the recirculation flow generated inside the plug promotes the rapid mixing of different solutions after plugs are merged, and it keeps cell suspensions homogeneous. Thus, serial dilutions of reagents and cell suspensions with different cell densities and cell types were rapidly performed using nanolitres of solution. Cells seeded through the plug processing grew well in the microdevice, and subsequent plug processing was used to detect the glucose consumption of cells and cellular responses to anticancer agents. The plug-based microdevice may provide a useful platform for cell-based assay systems in various fields, including fundamental cell biology and drug screening applications.
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Affiliation(s)
- Junji Fukuda
- Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305–8573, Japan
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Monbaliu JCM, Katritzky AR. Recent trends in Cys- and Ser/Thr-based synthetic strategies for the elaboration of peptide constructs. Chem Commun (Camb) 2012; 48:11601-22. [DOI: 10.1039/c2cc34434c] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Observation of spatial propagation of amyloid assembly from single nuclei. Proc Natl Acad Sci U S A 2011; 108:14746-51. [PMID: 21876182 DOI: 10.1073/pnas.1105555108] [Citation(s) in RCA: 109] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The crucial early stages of amyloid growth, in which normally soluble proteins are converted into fibrillar nanostructures, are challenging to study using conventional techniques yet are critical to the protein aggregation phenomena implicated in many common pathologies. As with all nucleation and growth phenomena, it is difficult to track individual nuclei in traditional macroscopic experiments, which probe the overall temporal evolution of the sample, but do not yield detailed information on the primary nucleation step as they mix independent stochastic events into an ensemble measurement. To overcome this limitation, we have developed microdroplet assays enabling us to detect single primary nucleation events and to monitor their subsequent spatial as well as temporal evolution, both of which we find to be determined by secondary nucleation phenomena. By deforming the droplets to high aspect ratio, we visualize in real-time propagating waves of protein assembly emanating from discrete primary nucleation sites. We show that, in contrast to classical gelation phenomena, the primary nucleation step is characterized by a striking dependence on system size, and the filamentous protein self-assembly process involves a highly nonuniform spatial distribution of aggregates. These findings deviate markedly from the current picture of amyloid growth and uncover a general driving force, originating from confinement, which, together with biological quality control mechanisms, helps proteins remain soluble and therefore functional in nature.
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Pompano RR, Liu W, Du W, Ismagilov RF. Microfluidics using spatially defined arrays of droplets in one, two, and three dimensions. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2011; 4:59-81. [PMID: 21370983 DOI: 10.1146/annurev.anchem.012809.102303] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Spatially defined arrays of droplets differ from bulk emulsions in that droplets in arrays can be indexed on the basis of one or more spatial variables to enable identification, monitoring, and addressability of individual droplets. Spatial indexing is critical in experiments with hundreds to millions of unique compartmentalized microscale processes--for example, in applications such as digital measurements of rare events in a large sample, high-throughput time-lapse studies of the contents of individual droplets, and controlled droplet-droplet interactions. This review describes approaches for spatially organizing and manipulating droplets in one-, two-, and three-dimensional structured arrays, including aspiration, laminar flow, droplet traps, the SlipChip, self-assembly, and optical or electrical fields. This review also presents techniques to analyze droplets in arrays and applications of spatially defined arrays, including time-lapse studies of chemical, enzymatic, and cellular processes, as well as further opportunities in chemical, biological, and engineering sciences, including perturbation/response experiments and personal and point-of-care diagnostics.
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Affiliation(s)
- Rebecca R Pompano
- Department of Chemistry and Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637, USA
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Zeng S, Liu X, Xie H, Lin B. Basic Technologies for Droplet Microfluidics. MICROFLUIDICS 2011; 304:69-90. [DOI: 10.1007/128_2011_149] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Shen F, Du W, Davydova EK, Karymov MA, Pandey J, Ismagilov RF. Nanoliter multiplex PCR arrays on a SlipChip. Anal Chem 2010; 82:4606-12. [PMID: 20446698 DOI: 10.1021/ac1007249] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The SlipChip platform was tested to perform high-throughput nanoliter multiplex PCR. The advantages of using the SlipChip platform for multiplex PCR include the ability to preload arrays of dry primers, instrument-free sample manipulation, small sample volume, and high-throughput capacity. The SlipChip was designed to preload one primer pair per reaction compartment and to screen up to 384 different primer pairs with less than 30 nanoliters of sample per reaction compartment. Both a 40-well and a 384-well design of the SlipChip were tested for multiplex PCR. In the geometries used here, the sample fluid was spontaneously compartmentalized into discrete volumes even before slipping of the two plates of the SlipChip, but slipping introduced additional capabilities that made devices more robust and versatile. The wells of this SlipChip were designed to overcome potential problems associated with thermal expansion. By using circular wells filled with oil and overlapping them with square wells filled with the aqueous PCR mixture, a droplet of aqueous PCR mixture was always surrounded by the lubricating fluid. In this design, during heating and thermal expansion, only oil was expelled from the compartment and leaking of the aqueous solution was prevented. Both 40-well and 384-well devices were found to be free from cross-contamination, and end point fluorescence detection provided reliable readout. Multiple samples could also be screened on the same SlipChip simultaneously. Multiplex PCR was validated on the 384-well SlipChip with 20 different primer pairs to identify 16 bacterial and fungal species commonly presented in blood infections. The SlipChip correctly identified five different bacterial or fungal species in separate experiments. In addition, the presence of the resistance gene mecA in methicillin resistant Staphylococcus aureus (MRSA) was identified. The SlipChip will be useful for applications involving PCR arrays and lays the foundation for new strategies for diagnostics, point-of-care devices, and immobilization-based arrays.
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Affiliation(s)
- Feng Shen
- Department of Chemistry and Institute for Biophysical Dynamics, The University of Chicago, 929 E 57th Street, Chicago, Illinois 60637, USA
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Theberge A, Courtois F, Schaerli Y, Fischlechner M, Abell C, Hollfelder F, Huck W. Microdroplets in Microfluidics: An Evolving Platform for Discoveries in Chemistry and Biology. Angew Chem Int Ed Engl 2010; 49:5846-68. [DOI: 10.1002/anie.200906653] [Citation(s) in RCA: 833] [Impact Index Per Article: 59.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Kreutz JE, Shukhaev A, Du W, Druskin S, Daugulis O, Ismagilov RF. Evolution of catalysts directed by genetic algorithms in a plug-based microfluidic device tested with oxidation of methane by oxygen. J Am Chem Soc 2010; 132:3128-32. [PMID: 20148558 PMCID: PMC2861856 DOI: 10.1021/ja909853x] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
This paper uses microfluidics to implement genetic algorithms (GA) to discover new homogeneous catalysts using the oxidation of methane by molecular oxygen as a model system. The parameters of the GA were the catalyst, a cocatalyst capable of using molecular oxygen as the terminal oxidant, and ligands that could tune the catalytic system. The GA required running hundreds of reactions to discover and optimize catalyst systems of high fitness, and microfluidics enabled these numerous reactions to be run in parallel. The small scale and volumes of microfluidics offer significant safety benefits. The microfluidic system included methods to form diverse arrays of plugs containing catalysts, introduce gaseous reagents at high pressure, run reactions in parallel, and detect catalyst activity using an in situ indicator system. Platinum(II) was identified as an active catalyst, and iron(II) and the polyoxometalate H(5)PMo(10)V(2)O(40) (POM-V2) were identified as active cocatalysts. The Pt/Fe system was further optimized and characterized using NMR experiments. After optimization, turnover numbers of approximately 50 were achieved with approximately equal production of methanol and formic acid. The Pt/Fe system demonstrated the compatibility of iron with the entire catalytic cycle. This approach of GA-guided evolution has the potential to accelerate discovery in catalysis and other areas where exploration of chemical space is essential, including optimization of materials for hydrogen storage and CO(2) capture and modifications.
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Affiliation(s)
- Jason E. Kreutz
- Department of Chemistry and Institute for Biophysical Dynamics, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637
| | - Anton Shukhaev
- Department of Chemistry and Institute for Biophysical Dynamics, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637
| | - Wenbin Du
- Department of Chemistry and Institute for Biophysical Dynamics, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637
| | - Sasha Druskin
- Department of Chemistry and Institute for Biophysical Dynamics, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637
| | - Olafs Daugulis
- Department of Chemistry, University of Houston, Houston, Texas 77204-5003
| | - Rustem F. Ismagilov
- Department of Chemistry and Institute for Biophysical Dynamics, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637
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Feng X, Yi Y, Yu X, Pang DW, Zhang ZL. Generation of water-ionic liquid droplet pairs in soybean oil on microfluidic chip. LAB ON A CHIP 2010; 10:313-319. [PMID: 20091002 DOI: 10.1039/b918167a] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Droplet-based microfluidic chips have shown great advantages in fields of chemical and biological researches. Based on the different wettabilities of water, IL (ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate) and soybean oil in hydrophobic channels, three kinds of droplet pairs (including an alternating water-IL droplet chain, connected water-IL droplet pairs and separated water-IL droplet pairs) were generated for the first time in soybean oil on microfluidic chips containing double flow-focusing regions. The influences of fluid flow rate and channel geometry on droplet pair formation were carefully studied.
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Affiliation(s)
- Xuan Feng
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 430072, P. R. China
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Abstract
The SlipChip is a microfluidic device designed to perform multiplexed microfluidic reactions without pumps or valves. The device has two plates in close contact. The bottom plate contains wells preloaded with many reagents; in this paper plates with 48 reagents were used. These wells are covered by the top plate that acts as a lid for the wells with reagents. The device also has a fluidic path, composed of ducts in the bottom plate and wells in the top plate, which is connected only when the top and bottom plate are aligned in a specific configuration. Sample can be added into the fluidic path, filling both wells and ducts. Then, the top plate is "slipped", or moved, relative to the bottom plate so the complementary patterns of wells in both plates overlap, exposing the sample-containing wells of the top plate to the reagent-containing wells of the bottom plate, and enabling diffusion and reactions. Between the two plates, a lubricating layer of fluorocarbon was used to facilitate relative motion of the plates. This paper implements this approach on a nanoliter scale using devices fabricated in glass. Stability of preloaded solutions, control of loading, and lack of cross-contamination were tested using fluorescent dyes. Functionality of the device was illustrated via crystallization of a model membrane protein. Fabrication of this device is simple and does not require a bonding step. This device requires no pumps or valves and is applicable to resource-poor settings. Overall, this device should be valuable for multiplexed applications that require exposing one sample to many reagents in small volumes. One may think of the SlipChip as an easy-to-use analogue of a preloaded multi-well plate, or a preloaded liquid-phase microarray.
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Affiliation(s)
- Wenbin Du
- Department of Chemistry and Institute for Biophysical Dynamics, The University of Chicago, 929 East 57 Street, Chicago, Illinois 60637, USA
| | - Liang Li
- Department of Chemistry and Institute for Biophysical Dynamics, The University of Chicago, 929 East 57 Street, Chicago, Illinois 60637, USA
| | - Kevin P. Nichols
- Department of Chemistry and Institute for Biophysical Dynamics, The University of Chicago, 929 East 57 Street, Chicago, Illinois 60637, USA
| | - Rustem F. Ismagilov
- Department of Chemistry and Institute for Biophysical Dynamics, The University of Chicago, 929 East 57 Street, Chicago, Illinois 60637, USA
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Kreutz JE, Li L, Roach LS, Hatakeyama T, Ismagilov RF. Laterally mobile, functionalized self-assembled monolayers at the fluorous-aqueous interface in a plug-based microfluidic system: characterization and testing with membrane protein crystallization. J Am Chem Soc 2009; 131:6042-3. [PMID: 19354215 DOI: 10.1021/ja808697e] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This paper describes a method to generate functionalizable, mobile self-assembled monolayers (SAMs) in plug-based microfluidics. Control of interfaces is advancing studies of biological interfaces, heterogeneous reactions, and nanotechnology. SAMs have been useful for such studies, but they are not laterally mobile. Lipid-based methods, though mobile, are not easily amenable to setting up the hundreds of experiments necessary for crystallization screening. Here we demonstrate a method, complementary to current SAM and lipid methods, for rapidly generating mobile, functionalized SAMs. This method relies on plugs, droplets surrounded by a fluorous carrier fluid, to rapidly explore chemical space. Specifically, we implemented his-tag binding chemistry to design a new fluorinated amphiphile, RfNTA, using an improved one-step synthesis of RfOEG under Mitsunobu conditions. RfNTA introduces specific binding of protein at the fluorous-aqueous interface, which concentrates and orients proteins at the interface, even in the presence of other surfactants. We then applied this approach to the crystallization of a his-tagged membrane protein, Reaction Center from Rhodobacter sphaeroides, performed 2400 crystallization trials, and showed that this approach can increase the range of crystal-producing conditions, the success rate at a given condition, the rate of nucleation, and the quality of the crystal formed.
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Affiliation(s)
- Jason E Kreutz
- Department of Chemistry, The University of Chicago, 929 East 57th Street, Chicago, Illinois 60637, USA
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