1
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Asor R, Olerinyova A, Burnap SA, Kushwah MS, Soltermann F, Rudden LSP, Hensen M, Vasiljevic S, Brun J, Hill M, Chang L, Dejnirattisai W, Supasa P, Mongkolsapaya J, Zhou D, Stuart DI, Screaton GR, Degiacomi MT, Zitzmann N, Benesch JLP, Struwe WB, Kukura P. Oligomerization-driven avidity correlates with SARS-CoV-2 cellular binding and inhibition. Proc Natl Acad Sci U S A 2024; 121:e2403260121. [PMID: 39298475 DOI: 10.1073/pnas.2403260121] [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] [Indexed: 09/21/2024] Open
Abstract
Cellular processes are controlled by the thermodynamics of the underlying biomolecular interactions. Frequently, structural investigations use one monomeric binding partner, while ensemble measurements of binding affinities generally yield one affinity representative of a 1:1 interaction, despite the majority of the proteome consisting of oligomeric proteins. For example, viral entry and inhibition in SARS-CoV-2 involve a trimeric spike surface protein, a dimeric angiotensin-converting enzyme 2 (ACE2) cell-surface receptor and dimeric antibodies. Here, we reveal that cooperativity correlates with infectivity and inhibition as opposed to 1:1 binding strength. We show that ACE2 oligomerizes spike more strongly for more infectious variants, while exhibiting weaker 1:1 affinity. Furthermore, we find that antibodies use induced oligomerization both as a primary inhibition mechanism and to enhance the effects of receptor-site blocking. Our results suggest that naive affinity measurements are poor predictors of potency, and introduce an antibody-based inhibition mechanism for oligomeric targets. More generally, they point toward a much broader role of induced oligomerization in controlling biomolecular interactions.
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Affiliation(s)
- Roi Asor
- Physical and Theoretical Chemistry, Department of Chemistry, University of Oxford, Oxford OX1 3QZ, United Kingdom
- The Kavli Institute for Nanoscience Discovery, Dorothy Crowfoot Hodgkin Building, University of Oxford, Oxford OX1 3QU, United Kingdom
| | - Anna Olerinyova
- Physical and Theoretical Chemistry, Department of Chemistry, University of Oxford, Oxford OX1 3QZ, United Kingdom
- The Kavli Institute for Nanoscience Discovery, Dorothy Crowfoot Hodgkin Building, University of Oxford, Oxford OX1 3QU, United Kingdom
| | - Sean A Burnap
- The Kavli Institute for Nanoscience Discovery, Dorothy Crowfoot Hodgkin Building, University of Oxford, Oxford OX1 3QU, United Kingdom
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom
| | - Manish S Kushwah
- Physical and Theoretical Chemistry, Department of Chemistry, University of Oxford, Oxford OX1 3QZ, United Kingdom
- The Kavli Institute for Nanoscience Discovery, Dorothy Crowfoot Hodgkin Building, University of Oxford, Oxford OX1 3QU, United Kingdom
| | - Fabian Soltermann
- Physical and Theoretical Chemistry, Department of Chemistry, University of Oxford, Oxford OX1 3QZ, United Kingdom
- The Kavli Institute for Nanoscience Discovery, Dorothy Crowfoot Hodgkin Building, University of Oxford, Oxford OX1 3QU, United Kingdom
| | - Lucas S P Rudden
- Department of Physics, Durham University, Durham DH1 3LE, United Kingdom
| | - Mario Hensen
- The Kavli Institute for Nanoscience Discovery, Dorothy Crowfoot Hodgkin Building, University of Oxford, Oxford OX1 3QU, United Kingdom
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom
| | - Snežana Vasiljevic
- The Kavli Institute for Nanoscience Discovery, Dorothy Crowfoot Hodgkin Building, University of Oxford, Oxford OX1 3QU, United Kingdom
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom
| | - Juliane Brun
- The Kavli Institute for Nanoscience Discovery, Dorothy Crowfoot Hodgkin Building, University of Oxford, Oxford OX1 3QU, United Kingdom
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom
| | - Michelle Hill
- The Kavli Institute for Nanoscience Discovery, Dorothy Crowfoot Hodgkin Building, University of Oxford, Oxford OX1 3QU, United Kingdom
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom
| | - Liu Chang
- Wellcome Centre for Human Genetics, Nuffield Department of Medicine, University of Oxford, Oxford OX3 7BN, United Kingdom
- Chinese Academy of Medical Science Oxford Institute, University of Oxford, Oxford OX3 7FZ, United Kingdom
| | - Wanwisa Dejnirattisai
- Wellcome Centre for Human Genetics, Nuffield Department of Medicine, University of Oxford, Oxford OX3 7BN, United Kingdom
- Division of Emerging Infectious Disease, Research Department, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkoknoi, Bangkok 10700, Thailand
| | - Piyada Supasa
- Wellcome Centre for Human Genetics, Nuffield Department of Medicine, University of Oxford, Oxford OX3 7BN, United Kingdom
| | - Juthathip Mongkolsapaya
- Wellcome Centre for Human Genetics, Nuffield Department of Medicine, University of Oxford, Oxford OX3 7BN, United Kingdom
- Chinese Academy of Medical Science Oxford Institute, University of Oxford, Oxford OX3 7FZ, United Kingdom
| | - Daming Zhou
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, United Kingdom
| | - David I Stuart
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, United Kingdom
- Diamond Light Source (United Kingdom), Harwell Science and Innovation Campus, Didcot OX110DE, United Kingdom
| | - Gavin R Screaton
- Wellcome Centre for Human Genetics, Nuffield Department of Medicine, University of Oxford, Oxford OX3 7BN, United Kingdom
- Oxford University Hospitals National Health Service Foundation Trust, Oxford OX3 7JH, United Kingdom
| | - Matteo T Degiacomi
- Department of Physics, Durham University, Durham DH1 3LE, United Kingdom
| | - Nicole Zitzmann
- The Kavli Institute for Nanoscience Discovery, Dorothy Crowfoot Hodgkin Building, University of Oxford, Oxford OX1 3QU, United Kingdom
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom
| | - Justin L P Benesch
- Physical and Theoretical Chemistry, Department of Chemistry, University of Oxford, Oxford OX1 3QZ, United Kingdom
- The Kavli Institute for Nanoscience Discovery, Dorothy Crowfoot Hodgkin Building, University of Oxford, Oxford OX1 3QU, United Kingdom
| | - Weston B Struwe
- The Kavli Institute for Nanoscience Discovery, Dorothy Crowfoot Hodgkin Building, University of Oxford, Oxford OX1 3QU, United Kingdom
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom
| | - Philipp Kukura
- Physical and Theoretical Chemistry, Department of Chemistry, University of Oxford, Oxford OX1 3QZ, United Kingdom
- The Kavli Institute for Nanoscience Discovery, Dorothy Crowfoot Hodgkin Building, University of Oxford, Oxford OX1 3QU, United Kingdom
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2
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Huang M, Chen Q, Liu Y, Zhang C, Zhang R, Yuan J, Zhang D. One-dimensional photonic crystal enhancing spin-to-orbital angular momentum conversion for single-particle tracking. LIGHT, SCIENCE & APPLICATIONS 2024; 13:268. [PMID: 39327427 PMCID: PMC11427464 DOI: 10.1038/s41377-024-01623-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2024] [Revised: 09/02/2024] [Accepted: 09/04/2024] [Indexed: 09/28/2024]
Abstract
Single-particle tracking (SPT) is an immensely valuable technique for studying a variety of processes in the life sciences and physics. It can help researchers better understand the positions, paths, and interactions of single objects in systems that are highly dynamic or require imaging over an extended time. Here, we propose an all-dielectric one-dimensional photonic crystal (1D PC) that enhances spin-to-orbital angular momentum conversion for three-dimensional (3D) SPTs. This well-designed 1D PC can work as a substrate for optical microscopy. We introduce this effect into the interferometric scattering (iSCAT) technique, resulting in a double-helix point spread function (DH-PSF). DH-PSF provides more uniform Fisher information for 3D position estimation than the PSFs of conventional microscopy, such as encoding the axial position of a single particle in the angular orientation of DH-PSF lobes, thus providing a means for 3D SPT. This approach can address the challenge of iSCAT in 3D SPT because DH-PSF iSCAT will not experience multiple contrast inversions when a single particle travels along the axial direction. DH-PSF iSCAT microscopy was used to record the 3D trajectory of a single microbead attached to the flagellum, facilitating precise analysis of fluctuations in motor dynamics. Its ability to track single nanoparticles, such as 3D diffusion trajectories of 20 nm gold nanoparticles in glycerol solution, was also demonstrated. The DH-PSF iSCAT technique enabled by a 1D PC holds potential promise for future applications in physical, biological, and chemical science.
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Affiliation(s)
- Mingchuan Huang
- Advanced Laser Technology Laboratory of Anhui Province, Department of Optics and Optical Engineering, University of Science and Technology of China, Hefei, Anhui, China
| | - Qiankun Chen
- Advanced Laser Technology Laboratory of Anhui Province, Department of Optics and Optical Engineering, University of Science and Technology of China, Hefei, Anhui, China
| | - Yang Liu
- Advanced Laser Technology Laboratory of Anhui Province, Department of Optics and Optical Engineering, University of Science and Technology of China, Hefei, Anhui, China
| | - Chi Zhang
- Department of Physics, University of Science and Technology of China, Hefei, Anhui, China
| | - Rongjin Zhang
- Department of Physics, University of Science and Technology of China, Hefei, Anhui, China
| | - Junhua Yuan
- Department of Physics, University of Science and Technology of China, Hefei, Anhui, China.
| | - Douguo Zhang
- Advanced Laser Technology Laboratory of Anhui Province, Department of Optics and Optical Engineering, University of Science and Technology of China, Hefei, Anhui, China.
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui, China.
- Hefei National Laboratory, University of Science and Technology of China, Hefei, China.
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3
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Clogston JD, Foss W, Harris D, Oberoi H, Pan J, Pu E, Guzmán EAT, Walter K, Brown S, Soo PL. Current state of nanomedicine drug products: An industry perspective. J Pharm Sci 2024:S0022-3549(24)00415-5. [PMID: 39276979 DOI: 10.1016/j.xphs.2024.09.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2024] [Revised: 09/09/2024] [Accepted: 09/09/2024] [Indexed: 09/17/2024]
Abstract
Nanomedicine drug products have reached an unprecedented high in terms of global commercial acceptance and media exposure with the approvals of the mRNA COVID-19 vaccines in 2021. In this paper, we examine the current state of the art for nanomedicine technologies as applied for pharmaceutical products and compare those trends with results from a recent IQ Consortium industry survey on nanomedicine drug products. We find that 1) industry companies continue to push the envelope in terms of new technologies for characterizing their specific drug products, 2) new analytical technologies continue to be utilized by industry to characterize the increasingly complex nanomedicine drug products and 3) alignment and communication are key between industry and regulatory authorities to better understand the regulatory filings that are being submitted. There are many CMC challenges that a company must overcome to successfully file a nanomedicine drug product. In 2022, the FDA Guidance on Drug Products containing Nanomaterials was published, and it provides a roadmap for submission of a nanomedicine drug product. We propose that our paper serves as a complimentary guide providing knowledge on specific CMC issues such as quality attributes, physicochemical characterization methods, excipients, and stability.
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Affiliation(s)
| | - Willard Foss
- Bristol Myers Squibb, Early Biologics Development, Redwood City, CA, USA
| | | | - Hardeep Oberoi
- AbbVie Inc., Drug Product Development, North Chicago, IL, USA
| | - Jiayi Pan
- Biogen, Technical Development, Cambridge, MA, USA
| | - Elaine Pu
- Bristol Myers Squibb, Drug Product Development, Summit, NJ, USA
| | | | - Katrin Walter
- AstraZeneca, Pharmaceutical Product Development, Gothenburg, Sweden
| | - Scott Brown
- GSK plc. Medicines Development and Supply, Drug Substance and Drug Product Analytical, Collegeville, PA 19426, USA
| | - Patrick Lim Soo
- Pfizer, Pharmaceutical Research & Development, Andover, MA, USA.
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4
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Kettel P, Marosits L, Spinetti E, Rechberger M, Giannini C, Radler P, Niedermoser I, Fischer I, Versteeg GA, Loose M, Covino R, Karagöz GE. Disordered regions in the IRE1α ER lumenal domain mediate its stress-induced clustering. EMBO J 2024:10.1038/s44318-024-00207-0. [PMID: 39232130 DOI: 10.1038/s44318-024-00207-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 07/02/2024] [Accepted: 07/23/2024] [Indexed: 09/06/2024] Open
Abstract
Conserved signaling cascades monitor protein-folding homeostasis to ensure proper cellular function. One of the evolutionary conserved key players is IRE1, which maintains endoplasmic reticulum (ER) homeostasis through the unfolded protein response (UPR). Upon accumulation of misfolded proteins in the ER, IRE1 forms clusters on the ER membrane to initiate UPR signaling. What regulates IRE1 cluster formation is not fully understood. Here, we show that the ER lumenal domain (LD) of human IRE1α forms biomolecular condensates in vitro. IRE1α LD condensates were stabilized both by binding to unfolded polypeptides as well as by tethering to model membranes, suggesting their role in assembling IRE1α into signaling-competent stable clusters. Molecular dynamics simulations indicated that weak multivalent interactions drive IRE1α LD clustering. Mutagenesis experiments identified disordered regions in IRE1α LD to control its clustering in vitro and in cells. Importantly, dysregulated clustering of IRE1α mutants led to defects in IRE1α signaling. Our results revealed that disordered regions in IRE1α LD control its clustering and suggest their role as a common strategy in regulating protein assembly on membranes.
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Affiliation(s)
- Paulina Kettel
- Max Perutz Laboratories Vienna, Vienna BioCenter, Vienna, Austria
- Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, Vienna, Austria
| | - Laura Marosits
- Max Perutz Laboratories Vienna, Vienna BioCenter, Vienna, Austria
- Medical University of Vienna, Vienna, Austria
| | - Elena Spinetti
- Frankfurt Institute for Advanced Studies, Frankfurt, Germany
- Institute of Biophysics, Goethe University, Frankfurt, Germany
| | | | - Caterina Giannini
- Institute of Science and Technology Austria, Klosterneuburg, Austria
| | - Philipp Radler
- Institute of Science and Technology Austria, Klosterneuburg, Austria
| | - Isabell Niedermoser
- Max Perutz Laboratories Vienna, Vienna BioCenter, Vienna, Austria
- Medical University of Vienna, Vienna, Austria
| | - Irmgard Fischer
- Max Perutz Laboratories Vienna, Vienna BioCenter, Vienna, Austria
| | - Gijs A Versteeg
- Max Perutz Laboratories Vienna, Vienna BioCenter, Vienna, Austria
- Department of Microbiology, Immunobiology and Genetics, University of Vienna, Vienna, Austria
| | - Martin Loose
- Institute of Science and Technology Austria, Klosterneuburg, Austria
| | - Roberto Covino
- Frankfurt Institute for Advanced Studies, Frankfurt, Germany
- IMPRS on Cellular Biophysics, Frankfurt, Germany
| | - G Elif Karagöz
- Max Perutz Laboratories Vienna, Vienna BioCenter, Vienna, Austria.
- Medical University of Vienna, Vienna, Austria.
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5
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Kratochvíl J, Asor R, Helmi S, Struwe WB, Kukura P. Lifting the Concentration Limit of Mass Photometry by PEG Nanopatterning. NANO LETTERS 2024; 24:10032-10039. [PMID: 38950386 PMCID: PMC11342371 DOI: 10.1021/acs.nanolett.4c01667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Revised: 06/24/2024] [Accepted: 06/25/2024] [Indexed: 07/03/2024]
Abstract
Mass photometry (MP) is a rapidly growing optical technique for label-free mass measurement of single biomolecules in solution. The underlying measurement principle provides numerous advantages over ensemble-based methods but has been limited to low analyte concentrations due to the need to uniquely and accurately quantify the binding of individual molecules to the measurement surface, which results in diffraction-limited spots. Here, we combine nanoparticle lithography with surface PEGylation to substantially lower surface binding, resulting in a 2 orders of magnitude improvement in the upper concentration limit associated with mass photometry. We demonstrate the facile tunability of degree of passivation, enabling measurements at increased analyte concentrations. These advances provide access to protein-protein interactions in the high nanomolar to low micromolar range, substantially expanding the application space of mass photometry.
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Affiliation(s)
- Jiří Kratochvíl
- The
Kavli Institute for Nanoscience Discovery, University of Oxford, Dorothy Crowfoot Hodgkin Building, South Parks Road, Oxford OX1 3QU, U.K.
- Physical
and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, U.K.
| | - Roi Asor
- The
Kavli Institute for Nanoscience Discovery, University of Oxford, Dorothy Crowfoot Hodgkin Building, South Parks Road, Oxford OX1 3QU, U.K.
- Physical
and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, U.K.
| | - Seham Helmi
- The
Kavli Institute for Nanoscience Discovery, University of Oxford, Dorothy Crowfoot Hodgkin Building, South Parks Road, Oxford OX1 3QU, U.K.
- Physical
and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, U.K.
| | - Weston B. Struwe
- The
Kavli Institute for Nanoscience Discovery, University of Oxford, Dorothy Crowfoot Hodgkin Building, South Parks Road, Oxford OX1 3QU, U.K.
- Department
of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, U.K.
| | - Philipp Kukura
- The
Kavli Institute for Nanoscience Discovery, University of Oxford, Dorothy Crowfoot Hodgkin Building, South Parks Road, Oxford OX1 3QU, U.K.
- Physical
and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, U.K.
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6
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Arragain B, Krischuns T, Pelosse M, Drncova P, Blackledge M, Naffakh N, Cusack S. Structures of influenza A and B replication complexes give insight into avian to human host adaptation and reveal a role of ANP32 as an electrostatic chaperone for the apo-polymerase. Nat Commun 2024; 15:6910. [PMID: 39160148 PMCID: PMC11333492 DOI: 10.1038/s41467-024-51007-3] [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: 02/08/2024] [Accepted: 07/16/2024] [Indexed: 08/21/2024] Open
Abstract
Replication of influenza viral RNA depends on at least two viral polymerases, a parental replicase and an encapsidase, and cellular factor ANP32. ANP32 comprises an LRR domain and a long C-terminal low complexity acidic region (LCAR). Here we present evidence suggesting that ANP32 is recruited to the replication complex as an electrostatic chaperone that stabilises the encapsidase moiety within apo-polymerase symmetric dimers that are distinct for influenza A and B polymerases. The ANP32 bound encapsidase, then forms the asymmetric replication complex with the replicase, which is embedded in a parental ribonucleoprotein particle (RNP). Cryo-EM structures reveal the architecture of the influenza A and B replication complexes and the likely trajectory of the nascent RNA product into the encapsidase. The cryo-EM map of the FluB replication complex shows extra density attributable to the ANP32 LCAR wrapping around and stabilising the apo-encapsidase conformation. These structures give new insight into the various mutations that adapt avian strain polymerases to use the distinct ANP32 in mammalian cells.
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Affiliation(s)
- Benoît Arragain
- European Molecular Biology Laboratory, Grenoble, Cedex 9, France
| | - Tim Krischuns
- Institut Pasteur, Université Paris Cité, CNRS UMR3569, RNA Biology of Influenza Virus, Paris, France
- Heidelberg University, Department of Infectious Diseases, Virology, Schaller Research Group, Heidelberg, Germany
| | - Martin Pelosse
- European Molecular Biology Laboratory, Grenoble, Cedex 9, France
| | - Petra Drncova
- European Molecular Biology Laboratory, Grenoble, Cedex 9, France
| | - Martin Blackledge
- Institut de Biologie Structurale, Université Grenoble-Alpes-CEA-CNRS UMR5075, Grenoble, France
| | - Nadia Naffakh
- Institut Pasteur, Université Paris Cité, CNRS UMR3569, RNA Biology of Influenza Virus, Paris, France
| | - Stephen Cusack
- European Molecular Biology Laboratory, Grenoble, Cedex 9, France.
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7
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Schneider F, Cespedes PF, Karedla N, Dustin ML, Fritzsche M. Quantifying biomolecular organisation in membranes with brightness-transit statistics. Nat Commun 2024; 15:7082. [PMID: 39152104 PMCID: PMC11329664 DOI: 10.1038/s41467-024-51435-1] [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: 03/05/2024] [Accepted: 08/07/2024] [Indexed: 08/19/2024] Open
Abstract
Cells crucially rely on the interactions of biomolecules at their plasma membrane to maintain homeostasis. Yet, a methodology to systematically quantify biomolecular organisation, measuring diffusion dynamics and oligomerisation, represents an unmet need. Here, we introduce the brightness-transit statistics (BTS) method based on fluorescence fluctuation spectroscopy and combine information from brightness and transit times to elucidate biomolecular diffusion and oligomerisation in both cell-free in vitro and in vitro systems incorporating living cells. We validate our approach in silico with computer simulations and experimentally using oligomerisation of EGFP tethered to supported lipid bilayers. We apply our pipeline to study the oligomerisation of CD40 ectodomain in vitro and endogenous CD40 on primary B cells. While we find a potential for CD40 to oligomerize in a concentration or ligand depended manner, we do not observe mobile oligomers on B cells. The BTS method combines sensitive analysis, quantification, and intuitive visualisation of dynamic biomolecular organisation.
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Affiliation(s)
- Falk Schneider
- Kennedy Institute for Rheumatology, Roosevelt Drive, University of Oxford, Oxford, OX3 7LF, United Kingdom.
- Translational Imaging Center, University of Southern California, Los Angeles, California, 90089, United States of America.
| | - Pablo F Cespedes
- Kennedy Institute for Rheumatology, Roosevelt Drive, University of Oxford, Oxford, OX3 7LF, United Kingdom
| | - Narain Karedla
- Kennedy Institute for Rheumatology, Roosevelt Drive, University of Oxford, Oxford, OX3 7LF, United Kingdom
- Rosalind Franklin Institute, Harwell Campus, Didcot, OX11 0FA, United Kingdom
| | - Michael L Dustin
- Kennedy Institute for Rheumatology, Roosevelt Drive, University of Oxford, Oxford, OX3 7LF, United Kingdom
| | - Marco Fritzsche
- Kennedy Institute for Rheumatology, Roosevelt Drive, University of Oxford, Oxford, OX3 7LF, United Kingdom.
- Rosalind Franklin Institute, Harwell Campus, Didcot, OX11 0FA, United Kingdom.
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8
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Pillai A, Idris A, Philomin A, Weidle C, Skotheim R, Leung PJY, Broerman A, Demakis C, Borst AJ, Praetorius F, Baker D. De novo design of allosterically switchable protein assemblies. Nature 2024; 632:911-920. [PMID: 39143214 PMCID: PMC11338832 DOI: 10.1038/s41586-024-07813-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 07/11/2024] [Indexed: 08/16/2024]
Abstract
Allosteric modulation of protein function, wherein the binding of an effector to a protein triggers conformational changes at distant functional sites, plays a central part in the control of metabolism and cell signalling1-3. There has been considerable interest in designing allosteric systems, both to gain insight into the mechanisms underlying such 'action at a distance' modulation and to create synthetic proteins whose functions can be regulated by effectors4-7. However, emulating the subtle conformational changes distributed across many residues, characteristic of natural allosteric proteins, is a significant challenge8,9. Here, inspired by the classic Monod-Wyman-Changeux model of cooperativity10, we investigate the de novo design of allostery through rigid-body coupling of peptide-switchable hinge modules11 to protein interfaces12 that direct the formation of alternative oligomeric states. We find that this approach can be used to generate a wide variety of allosterically switchable systems, including cyclic rings that incorporate or eject subunits in response to peptide binding and dihedral cages that undergo effector-induced disassembly. Size-exclusion chromatography, mass photometry13 and electron microscopy reveal that these designed allosteric protein assemblies closely resemble the design models in both the presence and absence of peptide effectors and can have ligand-binding cooperativity comparable to classic natural systems such as haemoglobin14. Our results indicate that allostery can arise from global coupling of the energetics of protein substructures without optimized side-chain-side-chain allosteric communication pathways and provide a roadmap for generating allosterically triggerable delivery systems, protein nanomachines and cellular feedback control circuitry.
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Affiliation(s)
- Arvind Pillai
- Department of Biochemistry, University of Washington, Seattle, WA, USA.
- Institute for Protein Design, University of Washington, Seattle, WA, USA.
| | - Abbas Idris
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
- Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Annika Philomin
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Connor Weidle
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Rebecca Skotheim
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Philip J Y Leung
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
- Program in Molecular Engineering, University of Washington, Seattle, WA, USA
| | - Adam Broerman
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
- Department of Chemical Engineering, University of Washington, Seattle, WA, USA
| | - Cullen Demakis
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
- Graduate Program in Biological Physics, Structure, and Design, University of Washington, Seattle, WA, USA
| | - Andrew J Borst
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Florian Praetorius
- Department of Biochemistry, University of Washington, Seattle, WA, USA.
- Institute for Protein Design, University of Washington, Seattle, WA, USA.
- Institute of Science and Technology Austria (ISTA), Klosterneuburg, Austria.
| | - David Baker
- Department of Biochemistry, University of Washington, Seattle, WA, USA.
- Institute for Protein Design, University of Washington, Seattle, WA, USA.
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9
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Roy J, Marathe I, Wysocki V, Pradeep T. Observing atomically precise nanocluster aggregates in solution by mass photometry. Chem Commun (Camb) 2024; 60:6655-6658. [PMID: 38856910 DOI: 10.1039/d4cc00363b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
We report the first mass photometric characterization of nanoaggregates of atomically precise nanoclusters (NCs) in solution. The differently-sized nanoaggregates of silver-gold alloy NCs, [Ag11-xAux(DPPB)5Cl5O2]2+ [x = 1-5 and DPPB = 1,4-bis(diphenylphosphino)butane], formed in solution, were examined by mass photometry (MP) with a protein calibration. In addition, we conducted MP studies of varying solvent composition to understand the structural evolution of nanoaggregates. The masses of nanoaggregates were correlated to structures of 15 to 50 nm diameter observed in cryo-electron microscopy.
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Affiliation(s)
- Jayoti Roy
- DST Unit of Nanoscience (DST UNS) & Thematic Unit of Excellence (TUE), Department of Chemistry, Indian Institute of Technology Madras (IITM), Chennai 600036, India.
| | - Ila Marathe
- Department of Chemistry and Biochemistry and Native Mass Spectrometry Guided Structural Biology Center, The Ohio State University, Columbus, Ohio 43210, USA
| | - Vicki Wysocki
- Department of Chemistry and Biochemistry and Native Mass Spectrometry Guided Structural Biology Center, The Ohio State University, Columbus, Ohio 43210, USA
| | - Thalappil Pradeep
- DST Unit of Nanoscience (DST UNS) & Thematic Unit of Excellence (TUE), Department of Chemistry, Indian Institute of Technology Madras (IITM), Chennai 600036, India.
- International Centre for Clean Water, 2nd Floor, B-Block, IIT Madras Research Park, Kanagam Road, Taramani, Chennai 600113, India
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10
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Velasco L, Islam AN, Kundu K, Oi A, Reinhard BM. Two-color interferometric scattering (iSCAT) microscopy reveals structural dynamics in discrete plasmonic molecules. NANOSCALE 2024; 16:11696-11704. [PMID: 38860984 PMCID: PMC11189637 DOI: 10.1039/d4nr01288g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Accepted: 06/03/2024] [Indexed: 06/12/2024]
Abstract
Plasmonic molecules are discrete assemblies of noble metal nanoparticles (NPs) that are of interest as transducers in optical nanosensors. So far, NPs with diameters of ∼40 nm have been the preferred building blocks for plasmonic molecules intended as optical single molecule sensors due to difficulties associated with detecting smaller NPs through elastic scattering in conventional darkfield microscopy. Here, we apply 405 nm, 445 nm two-color interferometric scattering (iSCAT) microscopy to characterize polyethylene glycol (PEG) tethered dimers of 10 nm and 20 nm Ag NPs and their monomers. Dimers of both NP sizes can be discerned from their respective monomers through changes in the average iSCAT contrast. In the case of 20 nm Ag NPs, dimer formation induces a change in the sign of the iSCAT contrast, providing a characteristic signal for detecting binding events. 20 nm Ag NP dimers with 0.4 kDa and 3.4 kDa polyethylene glycol (PEG) spacers show iSCAT contrast distributions with significantly different averages on both wavelength channels. The iSCAT contrast measured for individual PEG-tethered 10 nm or 20 nm NP dimers as a function of time shows contrast fluctuations indicative of a rich structural dynamics in the assembled plasmonic molecules, which provides an additional metric to discern dimers from monomers and paves the path to a new class of interferometric plasmon rulers.
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Affiliation(s)
- Leslie Velasco
- Department of Chemistry and The Photonics Center, Boston University, Boston, MA 02459, USA.
| | - Aniqa N Islam
- Department of Chemistry and The Photonics Center, Boston University, Boston, MA 02459, USA.
| | - Koustav Kundu
- Department of Chemistry and The Photonics Center, Boston University, Boston, MA 02459, USA.
| | - Aidan Oi
- Department of Chemistry and The Photonics Center, Boston University, Boston, MA 02459, USA.
| | - Björn M Reinhard
- Department of Chemistry and The Photonics Center, Boston University, Boston, MA 02459, USA.
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11
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Gizardin-Fredon H, Santo PE, Chagot ME, Charpentier B, Bandeiras TM, Manival X, Hernandez-Alba O, Cianférani S. Denaturing mass photometry for rapid optimization of chemical protein-protein cross-linking reactions. Nat Commun 2024; 15:3516. [PMID: 38664367 PMCID: PMC11045720 DOI: 10.1038/s41467-024-47732-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Accepted: 04/11/2024] [Indexed: 04/28/2024] Open
Abstract
Chemical cross-linking reactions (XL) are an important strategy for studying protein-protein interactions (PPIs), including low abundant sub-complexes, in structural biology. However, choosing XL reagents and conditions is laborious and mostly limited to analysis of protein assemblies that can be resolved using SDS-PAGE. To overcome these limitations, we develop here a denaturing mass photometry (dMP) method for fast, reliable and user-friendly optimization and monitoring of chemical XL reactions. The dMP is a robust 2-step protocol that ensures 95% of irreversible denaturation within only 5 min. We show that dMP provides accurate mass identification across a broad mass range (30 kDa-5 MDa) along with direct label-free relative quantification of all coexisting XL species (sub-complexes and aggregates). We compare dMP with SDS-PAGE and observe that, unlike the benchmark, dMP is time-efficient (3 min/triplicate), requires significantly less material (20-100×) and affords single molecule sensitivity. To illustrate its utility for routine structural biology applications, we show that dMP affords screening of 20 XL conditions in 1 h, accurately identifying and quantifying all coexisting species. Taken together, we anticipate that dMP will have an impact on ability to structurally characterize more PPIs and macromolecular assemblies, expected final complexes but also sub-complexes that form en route.
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Affiliation(s)
- Hugo Gizardin-Fredon
- Laboratoire de Spectrométrie de Masse BioOrganique, IPHC UMR 7178, Université de Strasbourg, CNRS, Strasbourg, France
- Infrastructure Nationale de Protéomique ProFI - FR2048, Strasbourg, France
| | - Paulo E Santo
- iBET, Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2781-901, Oeiras, Portugal
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157, Oeiras, Portugal
| | | | | | - Tiago M Bandeiras
- iBET, Instituto de Biologia Experimental e Tecnológica, Apartado 12, 2781-901, Oeiras, Portugal
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157, Oeiras, Portugal
| | | | - Oscar Hernandez-Alba
- Laboratoire de Spectrométrie de Masse BioOrganique, IPHC UMR 7178, Université de Strasbourg, CNRS, Strasbourg, France
- Infrastructure Nationale de Protéomique ProFI - FR2048, Strasbourg, France
| | - Sarah Cianférani
- Laboratoire de Spectrométrie de Masse BioOrganique, IPHC UMR 7178, Université de Strasbourg, CNRS, Strasbourg, France.
- Infrastructure Nationale de Protéomique ProFI - FR2048, Strasbourg, France.
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12
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Kowal MD, Seifried TM, Brouwer CC, Tavakolizadeh H, Olsén E, Grant E. Electrophoretic Deposition Interferometric Scattering Mass Photometry. ACS NANO 2024; 18:10388-10396. [PMID: 38567867 DOI: 10.1021/acsnano.3c09221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/17/2024]
Abstract
Interferometric scattering microscopy (iSCAT) has rapidly developed as a quantitative tool for the label-free detection of single macromolecules and nanoparticles. In practice, this measurement records the interferometric scattering signal of individual nanoparticles in solution as they land and stick on a coverslip, exhibiting an intensity that varies linearly with particle volume and an adsorption rate that reflects the solution-phase transport kinetics of the system. Together, such measurements provide a multidimensional gauge of the particle size and concentration in solution over time. However, the landing kinetics of particles in solution also manifest a measurement frequency limitation imposed by the slow long-range mobility of particle diffusion to the measurement interface. Here we introduce an effective means to overcome the inherent diffusion-controlled sampling limitation of spontaneous mass photometry. We term this methodology electrophoretic deposition interferometric scattering microscopy (EPD-iSCAT). This approach uses a coverslip supporting a conductive thin film of indium tin oxide (ITO). Charging this ITO film to a potential of around +1 V electrophoretically draws charged nanoparticles from solution and binds them in the focal plane of the microscope. Regulating this potential offers a direct means of controlling particle deposition. Thus, we find for a 0.1 nM solution of 50 nm polystyrene nanoparticles that the application of +1 V to an EPD-iSCAT coverslip assembly drives an electrophoretic deposition rate constant of 1.7 s-1 μm-2 nM-1. Removal of the potential causes deposition to cease. This user control of EPD-iSCAT affords a means to apply single-molecule mass photometry to monitor long-term changes in solution, owing to slow kinetic processes. In contrast with conventional coverslips chemically derivatized with charged thin films, EPD-iSCAT maintains a deposition rate that varies linearly with the bulk concentration.
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Affiliation(s)
- Matthew D Kowal
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Teresa M Seifried
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Carraugh C Brouwer
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Hooman Tavakolizadeh
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Erik Olsén
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, V6T 1Z4, Canada
| | - Edward Grant
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
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13
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Nguyen MC, Bonnaud P, Dibsy R, Maucort G, Lyonnais S, Muriaux D, Bon P. Label-Free Single Nanoparticle Identification and Characterization in Demanding Environment, Including Infectious Emergent Virus. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2304564. [PMID: 38009767 DOI: 10.1002/smll.202304564] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 10/02/2023] [Indexed: 11/29/2023]
Abstract
Unknown particle screening-including virus and nanoparticles-are keys in medicine, industry, and also in water pollutant determination. Here, RYtov MIcroscopy for Nanoparticles Identification (RYMINI) is introduced, a staining-free, non-invasive, and non-destructive optical approach that is merging holographic label-free 3D tracking with high-sensitivity quantitative phase imaging into a compact optical setup. Dedicated to the identification and then characterization of single nano-object in solution, it is compatible with highly demanding environments, such as level 3 biological laboratories, with high resilience to external source of mechanical and optical noise. Metrological characterization is performed at the level of each single particle on both absorbing and transparent particles as well as on immature and infectious HIV, SARS-CoV-2 and extracellular vesicles in solution. The capability of RYMINI to determine the nature, concentration, size, complex refractive index and mass of each single particle without knowledge or model of the particles' response is demonstrated. The system surpasses 90% accuracy for automatic identification between dielectric/metallic/biological nanoparticles and ≈80% for intraclass chemical determination of metallic and dielectric. It falls down to 50-70% for type determination inside the biological nanoparticle's class.
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Affiliation(s)
- Minh-Chau Nguyen
- UMR 7252, CNRS, XLIM, Université de Limoges, Limoges, F-87000, France
| | - Peter Bonnaud
- UMR 7252, CNRS, XLIM, Université de Limoges, Limoges, F-87000, France
| | - Rayane Dibsy
- UMR 9004 CNRS, IRIM (Institut de Recherche en Infectiologie de Montpellier), Université de Montpellier, Montpellier, F-34293, France
| | - Guillaume Maucort
- Laboratoire Photonique Numérique et Nanosciences, University of Bordeaux, Talence, F-33400, France
- LP2N UMR 5298, Institut d'Optique Graduate School, CNRS, Talence, F-33400, France
| | - Sébastien Lyonnais
- UAR 3725 CNRS, CEMIPAI, Université de Montpellier, Montpellier, F-34000, France
| | - Delphine Muriaux
- UMR 9004 CNRS, IRIM (Institut de Recherche en Infectiologie de Montpellier), Université de Montpellier, Montpellier, F-34293, France
- UAR 3725 CNRS, CEMIPAI, Université de Montpellier, Montpellier, F-34000, France
| | - Pierre Bon
- UMR 7252, CNRS, XLIM, Université de Limoges, Limoges, F-87000, France
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14
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De Vos J, Morreel K, Alvarez P, Vanluchene H, Vankeirsbilck R, Sandra P, Sandra K. Evaluation of size-exclusion chromatography, multi-angle light scattering detection and mass photometry for the characterization of mRNA. J Chromatogr A 2024; 1719:464756. [PMID: 38402695 DOI: 10.1016/j.chroma.2024.464756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 02/16/2024] [Accepted: 02/19/2024] [Indexed: 02/27/2024]
Abstract
The recent approval of messenger ribonucleic acid (mRNA) as vaccine to combat the COVID-19 pandemic has been a scientific turning point. Today, the applicability of mRNA is being demonstrated beyond infectious diseases, for example in cancer immunotherapy, protein replacement therapy and gene editing. mRNA is produced by in vitro transcription (IVT) from a linear DNA template and modified at the 3' and 5' ends to improve translational efficiency and stability. Co-existing impurities such as RNA fragments and double-stranded RNA (dsRNA), amongst others, can drastically impact mRNA quality and efficacy. In this study, size-exclusion chromatography (SEC) is evaluated for the characterization of IVT-mRNA. The effect of mobile phase composition (ionic strength and organic modifier), pH, column temperature and pore size (300 Å, 1000 Å, and 2000 Å) on the separation performance and structural integrity of IVT-mRNA varying in size is described. Non-replicating, self-amplifying (saRNA), temperature degraded, and ribonuclease (RNase) digested mRNA, the latter to characterize the 3' poly(A) tail, were included in the study. Beyond ultraviolet (UV) detection, refractive index (RI) and multi-angle light scattering (MALS) detection were implemented to accurately determine molecular weight (MW) of mRNA. Finally, mass photometry is introduced as a complementary methodology to study mRNA under native conditions.
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Affiliation(s)
- Jelle De Vos
- RIC group, President Kennedypark 6, 8500 Kortrijk, Belgium
| | - Kris Morreel
- RIC group, President Kennedypark 6, 8500 Kortrijk, Belgium
| | - Piotr Alvarez
- RIC group, President Kennedypark 6, 8500 Kortrijk, Belgium
| | | | | | - Pat Sandra
- RIC group, President Kennedypark 6, 8500 Kortrijk, Belgium
| | - Koen Sandra
- RIC group, President Kennedypark 6, 8500 Kortrijk, Belgium.
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15
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Liu Y, Chen Q, Zhang H, Feng Z, Zou G, Zhang D. Cascaded momentum-space polarization filters enabled label-free black-field microscopy for single nanoparticles analysis. Proc Natl Acad Sci U S A 2024; 121:e2321825121. [PMID: 38498716 PMCID: PMC10990084 DOI: 10.1073/pnas.2321825121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Accepted: 02/25/2024] [Indexed: 03/20/2024] Open
Abstract
Label-free optical imaging of single-nanometer-scale matter is extremely important for a variety of biomedical, physical, and chemical investigations. One central challenge is that the background intensity is much stronger than the intensity of the scattering light from single nano-objects. Here, we propose an optical module comprising cascaded momentum-space polarization filters that can perform vector field modulation to block most of the background field and result in an almost black background; in contrast, only a small proportion of the scattering field is blocked, leading to obvious imaging contrast enhancement. This module can be installed in various optical microscopies to realize a black-field microscopy. Various single nano-objects with dimensions smaller than 20 nm appear distinctly in the black-field images. The chemical reactions occurring on single nanocrystals with edge lengths of approximately 10 nm are in situ real-time monitored by using the black-field microscopy. This label-free black-field microscopy is highly promising for a wide range of future multidisciplinary science applications.
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Affiliation(s)
- Yang Liu
- Advanced Laser Technology Laboratory of Anhui Province, Department of Optics and Optical Engineering, University of Science and Technology of China, Hefei, Anhui230026, China
| | - Qiankun Chen
- Advanced Laser Technology Laboratory of Anhui Province, Department of Optics and Optical Engineering, University of Science and Technology of China, Hefei, Anhui230026, China
| | - Hongli Zhang
- Chinese Academy of Sciences Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui230026, China
| | - Zeyu Feng
- Chinese Academy of Sciences Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui230026, China
| | - Gang Zou
- Chinese Academy of Sciences Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui230026, China
| | - Douguo Zhang
- Advanced Laser Technology Laboratory of Anhui Province, Department of Optics and Optical Engineering, University of Science and Technology of China, Hefei, Anhui230026, China
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui230026, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei230088, China
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16
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Driscoll CL, Keeble AH, Howarth MR. SpyMask enables combinatorial assembly of bispecific binders. Nat Commun 2024; 15:2403. [PMID: 38493197 PMCID: PMC10944524 DOI: 10.1038/s41467-024-46599-9] [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: 09/03/2023] [Accepted: 03/04/2024] [Indexed: 03/18/2024] Open
Abstract
Bispecific antibodies are a successful and expanding therapeutic class. Standard approaches to generate bispecifics are complicated by the need for disulfide reduction/oxidation or specialized formats. Here we present SpyMask, a modular approach to bispecifics using SpyTag/SpyCatcher spontaneous amidation. Two SpyTag-fused antigen-binding modules can be precisely conjugated onto DoubleCatcher, a tandem SpyCatcher where the second SpyCatcher is protease-activatable. We engineer a panel of structurally-distinct DoubleCatchers, from which binders project in different directions. We establish a generalized methodology for one-pot assembly and purification of bispecifics in 96-well plates. A panel of binders recognizing different HER2 epitopes were coupled to DoubleCatcher, revealing unexpected combinations with anti-proliferative or pro-proliferative activity on HER2-addicted cancer cells. Bispecific activity depended sensitively on both binder orientation and DoubleCatcher scaffold geometry. These findings support the need for straightforward assembly in different formats. SpyMask provides a scalable tool to discover synergy in bispecific activity, through modulating receptor organization and geometry.
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Affiliation(s)
- Claudia L Driscoll
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1PD, UK
| | - Anthony H Keeble
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1PD, UK
| | - Mark R Howarth
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, UK.
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1PD, UK.
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17
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Zhou X, Chieng A, Wang S. Label-Free Optical Imaging of Nanoscale Single Entities. ACS Sens 2024; 9:543-554. [PMID: 38346398 PMCID: PMC10990724 DOI: 10.1021/acssensors.3c02526] [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] [Indexed: 02/24/2024]
Abstract
The advancement of optical microscopy technologies has achieved imaging of nanoscale objects, including nanomaterials, virions, organelles, and biological molecules, at the single entity level. Recently developed plasmonic and scattering based optical microscopy technologies have enabled label-free imaging of single entities with high spatial and temporal resolutions. These label-free methods eliminate the complexity of sample labeling and minimize the perturbation of the analyte native state. Additionally, these imaging-based methods can noninvasively probe the dynamics and functions of single entities with sufficient throughput for heterogeneity analysis. This perspective will review label-free single entity imaging technologies and discuss their principles, applications, and key challenges.
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Affiliation(s)
- Xinyu Zhou
- Biodesign Center for Bioelectronics and Biosensors, Arizona State University, Tempe, Arizona 85287, United States
- School of Biological and Health Systems Engineering, Arizona State University, Tempe, Arizona 85287, United States
| | - Andy Chieng
- Biodesign Center for Bioelectronics and Biosensors, Arizona State University, Tempe, Arizona 85287, United States
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
| | - Shaopeng Wang
- Biodesign Center for Bioelectronics and Biosensors, Arizona State University, Tempe, Arizona 85287, United States
- School of Biological and Health Systems Engineering, Arizona State University, Tempe, Arizona 85287, United States
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18
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Peters M, McIntosh D, Branzan Albu A, Ying C, Gordon R. Label-Free Tracking of Proteins through Plasmon-Enhanced Interference. ACS NANOSCIENCE AU 2024; 4:69-75. [PMID: 38406310 PMCID: PMC10885339 DOI: 10.1021/acsnanoscienceau.3c00045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 10/25/2023] [Accepted: 10/26/2023] [Indexed: 02/27/2024]
Abstract
Single unmodified biomolecules in solution can be observed and characterized by interferometric imaging approaches; however, Rayleigh scattering limits this to larger proteins (typically >30 kDa). We observe real-time image tracking of unmodified proteins down to 14 kDa using interference imaging enhanced by surface plasmons launched at an aperture in a metal film. The larger proteins show slower diffusion, quantified by tracking. When the diffusing protein is finally trapped by the nanoaperture, we perform complementary power spectral density and noise amplitude analysis, which gives information about the protein. This approach allows for rapid protein characterization with minimal sample preparation and opens the door to characterizing protein interactions in real time.
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Affiliation(s)
- Matthew Peters
- Department
of Electrical Engineering, University of
Victoria, Victoria, British Columbia V8W 2Y2, Canada
- Centre
for Advanced Materials & Related Technologies (CAMTEC), University of Victoria, Victoria, British Columbia V8W 2Y2, Canada
| | - Declan McIntosh
- Department
of Electrical Engineering, University of
Victoria, Victoria, British Columbia V8W 2Y2, Canada
| | - Alexandra Branzan Albu
- Department
of Electrical Engineering, University of
Victoria, Victoria, British Columbia V8W 2Y2, Canada
| | - Cuifeng Ying
- Advanced
Optics and Photonics Laboratory, Department of Engineering, School
of Science & Technology, Nottingham
Trent University, Nottingham NG11 8NS, U.K.
| | - Reuven Gordon
- Department
of Electrical Engineering, University of
Victoria, Victoria, British Columbia V8W 2Y2, Canada
- Centre
for Advanced Materials & Related Technologies (CAMTEC), University of Victoria, Victoria, British Columbia V8W 2Y2, Canada
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19
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Shaked NT, Boppart SA, Wang LV, Popp J. Label-free biomedical optical imaging. NATURE PHOTONICS 2023; 17:1031-1041. [PMID: 38523771 PMCID: PMC10956740 DOI: 10.1038/s41566-023-01299-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 08/22/2023] [Indexed: 03/22/2024]
Abstract
Label-free optical imaging employs natural and nondestructive approaches for the visualisation of biomedical samples for both biological assays and clinical diagnosis. Currently, this field revolves around multiple broad technology-oriented communities, each with a specific focus on a particular modality despite the existence of shared challenges and applications. As a result, biologists or clinical researchers who require label-free imaging are often not aware of the most appropriate modality to use. This manuscript presents a comprehensive review of and comparison among different label-free imaging modalities and discusses common challenges and applications. We expect this review to facilitate collaborative interactions between imaging communities, push the field forward and foster technological advancements, biophysical discoveries, as well as clinical detection, diagnosis, and monitoring of disease.
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Affiliation(s)
- Natan T Shaked
- Department of Biomedical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Stephen A Boppart
- Beckman Institute for Advanced Science and Technology, Department of Electrical and Computer Engineering,; Department of Bioengineering, University of Illinois Urbana-Champaign, Urbana, IL, USA
| | - Lihong V Wang
- Caltech Optical Imaging Laboratory, Andrew and Peggy Cherng Department of Medical Engineering, Department of Electrical Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Jürgen Popp
- Leibniz Institute of Photonic Technology, Member of Leibniz Health Technologies, Member of the Leibniz Centre for Photonics in Infection Research, Jena, Germany; Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich Schiller University Jena, Jena, Germany
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20
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Kabashin AV, Kravets VG, Grigorenko AN. Label-free optical biosensing: going beyond the limits. Chem Soc Rev 2023; 52:6554-6585. [PMID: 37681251 DOI: 10.1039/d3cs00155e] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/09/2023]
Abstract
Label-free optical biosensing holds great promise for a variety of applications in biomedical diagnostics, environmental and food safety, and security. It is already used as a key tool in the investigation of biomolecular binding events and reaction constants in real time and offers further potential additional functionalities and low-cost designs. However, the sensitivity of this technology does not match the routinely used but expensive and slow labelling methods. Therefore, label-free optical biosensing remains predominantly a research tool. Here we discuss how one can go beyond the limits of detection provided by standard optical biosensing platforms and achieve a sensitivity of label-free biosensing that is superior to labelling methods. To this end we review newly emerging optical implementations that overcome current sensitivity barriers by employing novel structural architectures, artificial materials (metamaterials and hetero-metastructures) and using phase of light as a sensing parameter. Furthermore, we elucidate the mechanism of plasmonic phase biosensing and review hyper-sensitive transducers, which can achieve detection limits at the single molecule level (less than 1 fg mm-2) and make it possible to detect analytes at several orders of magnitude lower concentrations than so far reported in literature. We finally discuss newly emerging layouts based on dielectric nanomaterials, bound states in continuum, and exceptional points.
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Affiliation(s)
- Andrei V Kabashin
- Aix Marseille Université, CNRS, UMR 7341 CNRS, LP3, Campus de Luminy-case 917, 13288, Marseille Cedex 9, France.
| | - Vasyl G Kravets
- School of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK.
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21
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Becker J, Peters JS, Crooks I, Helmi S, Synakewicz M, Schuler B, Kukura P. A Quantitative Description for Optical Mass Measurement of Single Biomolecules. ACS PHOTONICS 2023; 10:2699-2710. [PMID: 37602293 PMCID: PMC10436351 DOI: 10.1021/acsphotonics.3c00422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Indexed: 08/22/2023]
Abstract
Label-free detection of single biomolecules in solution has been achieved using a variety of experimental approaches over the past decade. Yet, our understanding of the magnitude of the optical contrast and its relationship with the underlying atomic structure as well as the achievable measurement sensitivity and precision remain poorly defined. Here, we use a Fourier optics approach combined with an atomic structure-based molecular polarizability model to simulate mass photometry experiments from first principles. We find excellent agreement between several key experimentally determined parameters such as optical contrast-to-mass conversion, achievable mass accuracy, and molecular shape and orientation dependence. This allows us to determine detection sensitivity and measurement precision mostly independent of the optical detection approach chosen, resulting in a general framework for light-based single-molecule detection and quantification.
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Affiliation(s)
- Jan Becker
- The
Kavli Institute for Nanoscience Discovery, University of Oxford, Dorothy Crowfoot Hodgkin Building, South Parks Rd, Oxford OX1 3QU, U.K.
- Physical
and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, U.K.
| | - Jack S. Peters
- The
Kavli Institute for Nanoscience Discovery, University of Oxford, Dorothy Crowfoot Hodgkin Building, South Parks Rd, Oxford OX1 3QU, U.K.
- Physical
and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, U.K.
| | - Ivor Crooks
- Physical
and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, U.K.
| | - Seham Helmi
- The
Kavli Institute for Nanoscience Discovery, University of Oxford, Dorothy Crowfoot Hodgkin Building, South Parks Rd, Oxford OX1 3QU, U.K.
- Physical
and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, U.K.
| | - Marie Synakewicz
- Department
of Biochemistry, University of Zurich, Winterthurerstrasse 190, Zurich 8057, Switzerland
| | - Benjamin Schuler
- Department
of Biochemistry, University of Zurich, Winterthurerstrasse 190, Zurich 8057, Switzerland
- Department
of Physics, University of Zurich, Winterthurerstrasse 190, Zurich 8057, Switzerland
| | - Philipp Kukura
- The
Kavli Institute for Nanoscience Discovery, University of Oxford, Dorothy Crowfoot Hodgkin Building, South Parks Rd, Oxford OX1 3QU, U.K.
- Physical
and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, U.K.
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22
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Reinhardt R, Leonard TA. A critical evaluation of protein kinase regulation by activation loop autophosphorylation. eLife 2023; 12:e88210. [PMID: 37470698 PMCID: PMC10359097 DOI: 10.7554/elife.88210] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 07/07/2023] [Indexed: 07/21/2023] Open
Abstract
Phosphorylation of proteins is a ubiquitous mechanism of regulating their function, localization, or activity. Protein kinases, enzymes that use ATP to phosphorylate protein substrates are, therefore, powerful signal transducers in eukaryotic cells. The mechanism of phosphoryl-transfer is universally conserved among protein kinases, which necessitates the tight regulation of kinase activity for the orchestration of cellular processes with high spatial and temporal fidelity. In response to a stimulus, many kinases enhance their own activity by autophosphorylating a conserved amino acid in their activation loop, but precisely how this reaction is performed is controversial. Classically, kinases that autophosphorylate their activation loop are thought to perform the reaction in trans, mediated by transient dimerization of their kinase domains. However, motivated by the recently discovered regulation mechanism of activation loop cis-autophosphorylation by a kinase that is autoinhibited in trans, we here review the various mechanisms of autoregulation that have been proposed. We provide a framework for critically evaluating biochemical, kinetic, and structural evidence for protein kinase dimerization and autophosphorylation, and share some thoughts on the implications of these mechanisms within physiological signaling networks.
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Affiliation(s)
- Ronja Reinhardt
- Max Perutz Labs, Vienna Biocenter Campus (VBC)ViennaAustria
- Medical University of Vienna, Center for Medical BiochemistryViennaAustria
| | - Thomas A Leonard
- Max Perutz Labs, Vienna Biocenter Campus (VBC)ViennaAustria
- Medical University of Vienna, Center for Medical BiochemistryViennaAustria
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23
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Zhou AXZ, Hammond JA, Sheng K, Millar DP, Williamson JR. Early HIV-1 Gag Assembly on Lipid Membrane with vRNA. RESEARCH SQUARE 2023:rs.3.rs-3060076. [PMID: 37461524 PMCID: PMC10350206 DOI: 10.21203/rs.3.rs-3060076/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/24/2023]
Abstract
HIV-1 capsid assembly is an essential process in the virus infection cycle. Initiation of capsid assembly involves viral proteins, genomic RNA, and the inner leaflet of the plasma membrane, facilitated by a number of cellular factors1. The viral structural protein Gag plays a number of central roles in this process, including association with the membrane, selective binding of genomic RNA, and oligomerization and packaging to ultimately produce an immature budded pro-viral particle2. While there have been intensive studies regarding the early stages of Gag assembly, there is a lack of consensus on the mechanism for nucleation and growth of Gag complexes3-7. Here we show that myristoylated Gag forms a trimer nucleus in a model membrane that can selectively bind a dimeric RNA containing the packaging signal. Subsequent growth of myristoyl-Gag oligomers requires vRNA, and occurs by addition of 1 or 2 Gag monomers at a time from solution. These data support a model where the immature capsid lattice formation occurs by a gradual lattice edge expansion, following a trimeric nucleation event. The dynamic single molecule data that support this model were recorded using mass photometry, involving full length myristoylated protein, RNA, and lipid together. These data are the first to support a lattice edge expansion model of Gag during early stages of assembly in a biological-relevant setting, providing insights to the fundamental models of virus structural protein assembly process.
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Affiliation(s)
- Anne X.-Z. Zhou
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute; La Jolla, CA 92037, USA
| | - John A. Hammond
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute; La Jolla, CA 92037, USA
| | - Kai Sheng
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute; La Jolla, CA 92037, USA
| | - David P. Millar
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute; La Jolla, CA 92037, USA
| | - James R. Williamson
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute; La Jolla, CA 92037, USA
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24
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Rivera M, Burgos‐Bravo F, Engelberger F, Asor R, Lagos‐Espinoza MIA, Figueroa M, Kukura P, Ramírez‐Sarmiento CA, Baez M, Smith SB, Wilson CAM. Effect of temperature and nucleotide on the binding of BiP chaperone to a protein substrate. Protein Sci 2023; 32:e4706. [PMID: 37323096 PMCID: PMC10303699 DOI: 10.1002/pro.4706] [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: 12/18/2022] [Revised: 06/01/2023] [Accepted: 06/12/2023] [Indexed: 06/17/2023]
Abstract
BiP (immunoglobulin heavy-chain binding protein) is a Hsp70 monomeric ATPase motor that plays broad and crucial roles in maintaining proteostasis inside the cell. Structurally, BiP is formed by two domains, a nucleotide-binding domain (NBD) with ATPase activity connected by a flexible hydrophobic linker to the substrate-binding domain. While the ATPase and substrate binding activities of BiP are allosterically coupled, the latter is also dependent on nucleotide binding. Recent structural studies have provided new insights into BiP's allostery; however, the influence of temperature on the coupling between substrate and nucleotide binding to BiP remains unexplored. Here, we study BiP's binding to its substrate at the single molecule level using thermo-regulated optical tweezers which allows us to mechanically unfold the client protein and explore the effect of temperature and different nucleotides on BiP binding. Our results confirm that the affinity of BiP for its protein substrate relies on nucleotide binding, by mainly regulating the binding kinetics between BiP and its substrate. Interestingly, our findings also showed that the apparent affinity of BiP for its protein substrate in the presence of nucleotides remains invariable over a wide range of temperatures, suggesting that BiP may interact with its client proteins with similar affinities even when the temperature is not optimal. Thus, BiP could play a role as a "thermal buffer" in proteostasis.
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Affiliation(s)
- Maira Rivera
- Institute for Biological and Medical Engineering, Schools of Engineering, Medicine and Biological SciencesPontificia Universidad Católica de ChileSantiagoChile
- ANID–Millennium Science Initiative Program–Millennium Institute for Integrative Biology (iBio)SantiagoChile
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas y FarmacéuticasUniversidad de ChileSantiagoChile
| | - Francesca Burgos‐Bravo
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas y FarmacéuticasUniversidad de ChileSantiagoChile
- Institute for Quantitative BiosciencesUniversity of CaliforniaBerkeleyCaliforniaUSA
| | - Felipe Engelberger
- Institute for Biological and Medical Engineering, Schools of Engineering, Medicine and Biological SciencesPontificia Universidad Católica de ChileSantiagoChile
- ANID–Millennium Science Initiative Program–Millennium Institute for Integrative Biology (iBio)SantiagoChile
| | - Roi Asor
- Physical and Theoretical Chemistry Laboratory, Department of ChemistryUniversity of OxfordOxfordUK
- The Kavli Institute for Nanoscience DiscoveryOxfordUK
| | - Miguel I. A. Lagos‐Espinoza
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas y FarmacéuticasUniversidad de ChileSantiagoChile
| | - Maximiliano Figueroa
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias BiológicasUniversidad de ConcepciónConcepciónChile
| | - Philipp Kukura
- Physical and Theoretical Chemistry Laboratory, Department of ChemistryUniversity of OxfordOxfordUK
- The Kavli Institute for Nanoscience DiscoveryOxfordUK
| | - César A. Ramírez‐Sarmiento
- Institute for Biological and Medical Engineering, Schools of Engineering, Medicine and Biological SciencesPontificia Universidad Católica de ChileSantiagoChile
- ANID–Millennium Science Initiative Program–Millennium Institute for Integrative Biology (iBio)SantiagoChile
| | - Mauricio Baez
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas y FarmacéuticasUniversidad de ChileSantiagoChile
| | | | - Christian A. M. Wilson
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas y FarmacéuticasUniversidad de ChileSantiagoChile
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25
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Gordon MT, Ziemba BP, Falke JJ. PDK1:PKCα heterodimer association-dissociation dynamics in single-molecule diffusion tracks on a target membrane. Biophys J 2023; 122:2301-2310. [PMID: 36733254 PMCID: PMC10257113 DOI: 10.1016/j.bpj.2023.01.041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2022] [Revised: 12/01/2022] [Accepted: 01/30/2023] [Indexed: 02/04/2023] Open
Abstract
Previous studies have documented the formation of a heterodimer between the two protein kinases PDK1 and PKCα on a lipid bilayer containing their target lipids. This work investigates the association-dissociation kinetics of this PDK1:PKCα heterodimer. The approach monitors the two-dimensional diffusion of single, membrane-associated PDK1 molecules for diffusivity changes as PKCα molecules bind and unbind. In the absence of PKCα, a membrane-associated PDK1 molecule exhibits high diffusivity (or large diffusion constant, D) because its membrane-contacting PH domain binds the target PIP3 lipid headgroup with little bilayer penetration, yielding minimal frictional drag against the bilayer. In contrast, membrane-associated PKCα contacts the bilayer via its C1A, C1B, and C2 domains, which each bind at least one target lipid with significant bilayer insertion, yielding a large frictional drag and low diffusivity. The present findings reveal that individual fluor-PDK1 molecules freely diffusing on the membrane surface undergo reversible switching between distinct high and low diffusivity states, corresponding to the PDK1 monomer and the PDK1:PKCα heterodimer, respectively. The observed single-molecule diffusion trajectories are converted to step length time courses, then subjected to two-state, hidden Markov modeling and dwell time analysis. The findings reveal that both the PDK1 monomer state and the PDK1:PKCα heterodimer state decay via simple exponential kinetics, yielding estimates of rate constants for state switching in both directions. Notably, the PDK1:PKCα heterodimer has been shown to competitively inhibit PDK1 phosphoactivation of AKT1, and is believed to play a tumor suppressor role by limiting excess activation of the highly oncogenic PDK1/AKT1/mTOR pathway. Thus, the present elucidation of the PDK1:PKCα association-dissociation kinetics has important biological and medical implications. More broadly, the findings illustrate the power of single-molecule diffusion measurements to reveal the kinetics of association-dissociation events in membrane signaling reactions that yield a large change in diffusive mobility.
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Affiliation(s)
- Moshe T Gordon
- Molecular Biophysics Program and Department of Biochemistry, University of Colorado, Boulder, Colorado
| | - Brian P Ziemba
- Molecular Biophysics Program and Department of Biochemistry, University of Colorado, Boulder, Colorado
| | - Joseph J Falke
- Molecular Biophysics Program and Department of Biochemistry, University of Colorado, Boulder, Colorado.
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26
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Zhang P, Zhou X, Wang S. Plasmonic Scattering Microscopy for Label-Free Imaging of Molecular Binding Kinetics: From Single Molecules to Single Cells. CHEMISTRY METHODS : NEW APPROACHES TO SOLVING PROBLEMS IN CHEMISTRY 2023; 3:e202200066. [PMID: 37448471 PMCID: PMC10344632 DOI: 10.1002/cmtd.202200066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Indexed: 07/15/2023]
Abstract
Measuring molecular binding kinetics represents one of the most important tasks in molecular interaction analysis. Surface plasmon resonance (SPR) is a popular tool for analyzing molecular binding. Plasmonic scattering microscopy (PSM) is a newly developed SPR imaging technology, which detects the out-of-plane scattering of surface plasmons by analytes and has pushed the detection limit of label-free SPR imaging down to a single-protein level. In addition, PSM also allows SPR imaging with high spatiotemporal resolution, making it possible to analyze cellular response to the molecular bindings. In this Mini Review, we present PSM as a method of choice for chemical and biological imaging, introduce its theoretical mechanism, present its experimental schemes, summarize its exciting applications, and discuss its challenges as well as the promising future.
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Affiliation(s)
- Pengfei Zhang
- Biodesign Center for Bioelectronics and Biosensors, Arizona State University, Tempe, AZ, 85287 (USA)
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190 (P. R. China)
| | - Xinyu Zhou
- Biodesign Center for Bioelectronics and Biosensors, Arizona State University, Tempe, AZ, 85287 (USA)
- School of Biological and Health Systems Engineering, Arizona State University, Tempe, AZ 85287 (USA)
| | - Shaopeng Wang
- Biodesign Center for Bioelectronics and Biosensors, Arizona State University, Tempe, AZ, 85287 (USA)
- School of Biological and Health Systems Engineering, Arizona State University, Tempe, AZ 85287 (USA)
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27
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Liu L, Tibbs J, Li N, Bacon A, Shepherd S, Lee H, Chauhan N, Demirci U, Wang X, Cunningham BT. A photonic resonator interferometric scattering microscope for label-free detection of nanometer-scale objects with digital precision in point-of-use environments. Biosens Bioelectron 2023; 228:115197. [PMID: 36905862 PMCID: PMC10072782 DOI: 10.1016/j.bios.2023.115197] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 02/27/2023] [Accepted: 03/04/2023] [Indexed: 03/08/2023]
Abstract
Label-free detection and digital counting of nanometer-scaled objects such as nanoparticles, viruses, extracellular vesicles, and protein molecules enable a wide range of applications in cancer diagnostics, pathogen detection, and life science research. Here, we report the design, implementation, and characterization of a compact Photonic Resonator Interferometric Scattering Microscope (PRISM) designed for point-of-use environments and applications. The contrast of interferometric scattering microscopy is amplified through a photonic crystal surface, upon which scattered light from an object combines with illumination from a monochromatic source. The use of a photonic crystal substrate for interferemetric scattering microscopy results in reduced requirements for high-intensity lasers or oil-immersion objectives, thus opening a pathway toward instruments that are more suitable for environments outside the optics laboratory. The instrument incorporates two innovative elements that facilitate operation on a desktop in ordinary laboratory environments by users that do not have optics expertise. First, because scattering microscopes are extremely sensitive to vibration, we incorporated an inexpensive but effective solution of suspending the instrument's main components from a rigid metal framework using elastic bands, resulting in an average of 28.7 dBV reduction in vibration amplitude compared to an office desk. Second, an automated focusing module based on the principle of total internal reflection maintains the stability of image contrast over time and spatial position. In this work, we characterize the system's performance by measuring the contrast from gold nanoparticles with diameters in the 10-40 nm range and by observing various biological analytes, including HIV virus, SARS-CoV-2 virus, exosome, and ferritin protein.
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Affiliation(s)
- Leyang Liu
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA; Nick Holonyak Jr. Micro and Nanotechnology Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Joseph Tibbs
- Nick Holonyak Jr. Micro and Nanotechnology Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA; Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Nantao Li
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA; Nick Holonyak Jr. Micro and Nanotechnology Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Amanda Bacon
- Nick Holonyak Jr. Micro and Nanotechnology Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA; Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Skye Shepherd
- Nick Holonyak Jr. Micro and Nanotechnology Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA; Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Hankeun Lee
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA; Nick Holonyak Jr. Micro and Nanotechnology Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Neha Chauhan
- Nick Holonyak Jr. Micro and Nanotechnology Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA; Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA; Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Utkan Demirci
- Canary Center at Stanford for Cancer Early Detection, Stanford School of Medicine, Stanford University, Palo Alto, CA, 94304, USA
| | - Xing Wang
- Nick Holonyak Jr. Micro and Nanotechnology Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA; Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA; Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Brian T Cunningham
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA; Nick Holonyak Jr. Micro and Nanotechnology Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA; Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA; Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA; Cancer Center at Illinois, Urbana, IL, 61801, USA.
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28
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Boyle MJ, Goldman YE, Composto RJ. Enhancing Nanoparticle Detection in Interferometric Scattering (iSCAT) Microscopy Using a Mask R-CNN. J Phys Chem B 2023; 127:3737-3745. [PMID: 37074024 DOI: 10.1021/acs.jpcb.3c00097] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/20/2023]
Abstract
Interferometric scattering microscopy (iSCAT) is a label-free optical microscopy technique that enables imaging of individual nano-objects such as nanoparticles, viruses, and proteins. Essential to this technique is the suppression of background scattering and identification of signals from nano-objects. In the presence of substrates with high roughness, scattering heterogeneities in the background, when coupled with tiny stage movements, cause features in the background to be manifested in background-suppressed iSCAT images. Traditional computer vision algorithms detect these background features as particles, limiting the accuracy of object detection in iSCAT experiments. Here, we present a pathway to improve particle detection in such situations using supervised machine learning via a mask region-based convolutional neural network (mask R-CNN). Using a model iSCAT experiment of 19.2 nm gold nanoparticles adsorbing to a rough layer-by-layer polyelectrolyte film, we develop a method to generate labeled datasets using experimental background images and simulated particle signals and train the mask R-CNN using limited computational resources via transfer learning. We then compare the performance of the mask R-CNN trained with and without inclusion of experimental backgrounds in the dataset against that of a traditional computer vision object detection algorithm, Haar-like feature detection, by analyzing data from the model experiment. Results demonstrate that including representative backgrounds in training datasets improved the mask R-CNN in differentiating between background and particle signals and elevated performance by markedly reducing false positives. The methodology for creating a labeled dataset with representative experimental backgrounds and simulated signals facilitates the application of machine learning in iSCAT experiments with strong background scattering and thus provides a useful workflow for future researchers to improve their image processing capabilities.
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Affiliation(s)
- Michael J Boyle
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Center for Engineered Materials and Manufacturing, Lawrence Livermore National Laboratory, Livermore, California 94550, United States
| | - Yale E Goldman
- Department of Physiology and Pennsylvania Muscle Institute, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Russell J Composto
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
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29
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Küppers M, Albrecht D, Kashkanova AD, Lühr J, Sandoghdar V. Confocal interferometric scattering microscopy reveals 3D nanoscopic structure and dynamics in live cells. Nat Commun 2023; 14:1962. [PMID: 37029107 PMCID: PMC10081331 DOI: 10.1038/s41467-023-37497-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Accepted: 03/16/2023] [Indexed: 04/09/2023] Open
Abstract
Bright-field light microscopy and related phase-sensitive techniques play an important role in life sciences because they provide facile and label-free insights into biological specimens. However, lack of three-dimensional imaging and low sensitivity to nanoscopic features hamper their application in many high-end quantitative studies. Here, we demonstrate that interferometric scattering (iSCAT) microscopy operated in the confocal mode provides unique label-free solutions for live-cell studies. We reveal the nanometric topography of the nuclear envelope, quantify the dynamics of the endoplasmic reticulum, detect single microtubules, and map nanoscopic diffusion of clathrin-coated pits undergoing endocytosis. Furthermore, we introduce the combination of confocal and wide-field iSCAT modalities for simultaneous imaging of cellular structures and high-speed tracking of nanoscopic entities such as single SARS-CoV-2 virions. We benchmark our findings against simultaneously acquired fluorescence images. Confocal iSCAT can be readily implemented as an additional contrast mechanism in existing laser scanning microscopes. The method is ideally suited for live studies on primary cells that face labeling challenges and for very long measurements beyond photobleaching times.
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Affiliation(s)
- Michelle Küppers
- Max Planck Institute for the Science of Light, 91058, Erlangen, Germany
- Max-Planck-Zentrum für Physik und Medizin, 91058, Erlangen, Germany
- Department of Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91058, Erlangen, Germany
| | - David Albrecht
- Max Planck Institute for the Science of Light, 91058, Erlangen, Germany
- Max-Planck-Zentrum für Physik und Medizin, 91058, Erlangen, Germany
| | - Anna D Kashkanova
- Max Planck Institute for the Science of Light, 91058, Erlangen, Germany
- Max-Planck-Zentrum für Physik und Medizin, 91058, Erlangen, Germany
| | - Jennifer Lühr
- Max Planck Institute for the Science of Light, 91058, Erlangen, Germany
- Max-Planck-Zentrum für Physik und Medizin, 91058, Erlangen, Germany
| | - Vahid Sandoghdar
- Max Planck Institute for the Science of Light, 91058, Erlangen, Germany.
- Max-Planck-Zentrum für Physik und Medizin, 91058, Erlangen, Germany.
- Department of Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91058, Erlangen, Germany.
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30
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Gibbs E, Klemm E, Seiferth D, Kumar A, Ilca SL, Biggin PC, Chakrapani S. Conformational transitions and allosteric modulation in a heteromeric glycine receptor. Nat Commun 2023; 14:1363. [PMID: 36914669 PMCID: PMC10011588 DOI: 10.1038/s41467-023-37106-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Accepted: 03/02/2023] [Indexed: 03/16/2023] Open
Abstract
Glycine Receptors (GlyRs) provide inhibitory neuronal input in the spinal cord and brainstem, which is critical for muscle coordination and sensory perception. Synaptic GlyRs are a heteromeric assembly of α and β subunits. Here we present cryo-EM structures of full-length zebrafish α1βBGlyR in the presence of an antagonist (strychnine), agonist (glycine), or agonist with a positive allosteric modulator (glycine/ivermectin). Each structure shows a distinct pore conformation with varying degrees of asymmetry. Molecular dynamic simulations found the structures were in a closed (strychnine) and desensitized states (glycine and glycine/ivermectin). Ivermectin binds at all five interfaces, but in a distinct binding pose at the β-α interface. Subunit-specific features were sufficient to solve structures without a fiduciary marker and to confirm the 4α:1β stoichiometry recently observed. We also report features of the extracellular and intracellular domains. Together, our results show distinct compositional and conformational properties of α1βGlyR and provide a framework for further study of this physiologically important channel.
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Affiliation(s)
- Eric Gibbs
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH, 44106-4970, USA
| | - Emily Klemm
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH, 44106-4970, USA
| | - David Seiferth
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK
| | - Arvind Kumar
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH, 44106-4970, USA
| | - Serban L Ilca
- New York Structural Biology Center, New York, NY, 10027, USA
- Simons Electron Microscopy Center, New York, NY, 10027, USA
| | - Philip C Biggin
- Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK
| | - Sudha Chakrapani
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH, 44106-4970, USA.
- Department of Neuroscience, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106-4970, USA.
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31
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Younas T, Liu C, Struwe WB, Kukura P, He L. Engineer RNA-Protein Nanowires as Light-Responsive Biomaterials. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2206513. [PMID: 36642821 DOI: 10.1002/smll.202206513] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 12/15/2022] [Indexed: 06/17/2023]
Abstract
RNA molecules have emerged as increasingly attractive biomaterials with important applications such as RNA interference (RNAi) for cancer treatment and mRNA vaccines against infectious diseases. However, it remains challenging to engineer RNA biomaterials with sophisticated functions such as non-covalent light-switching ability. Herein, light-responsive RNA-protein nanowires are engineered to have such functions. It first demonstrates that the high affinity of RNA aptamer enables the formation of long RNA-protein nanowires through designing a dimeric RNA aptamer and an engineered green fluorescence protein (GFP) that contains two TAT-derived peptides at N- and C- termini. GFP is then replaced with an optogenetic protein pair system, LOV2 (light-oxygen-voltage) protein and its binding partner ZDK (Z subunit of protein A), to confer blue light-controlled photo-switching ability. The light-responsive nanowires are long (>500 nm) in the dark, but small (20-30 nm) when exposed to light. Importantly, the co-assembly of this RNA-protein hybrid biomaterial does not rely on the photochemistry commonly used for light-responsive biomaterials, such as bond formation, cleavage, and isomerization, and is thus reversible. These RNA-protein structures can serve as a new class of light-controlled biocompatible frameworks for incorporating versatile elements such as RNA, DNA, and enzymes.
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Affiliation(s)
- Tayyaba Younas
- Department of Chemical and Biological Engineering, Monash University, Clayton, VIC, 3800, Australia
| | - Chang Liu
- Department of Chemical and Biological Engineering, Monash University, Clayton, VIC, 3800, Australia
| | - Weston B Struwe
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford, OX1 3QZ, UK
| | - Philipp Kukura
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford, OX1 3QZ, UK
| | - Lizhong He
- Department of Chemical and Biological Engineering, Monash University, Clayton, VIC, 3800, Australia
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Margheritis E, Kappelhoff S, Cosentino K. Pore-Forming Proteins: From Pore Assembly to Structure by Quantitative Single-Molecule Imaging. Int J Mol Sci 2023; 24:ijms24054528. [PMID: 36901959 PMCID: PMC10003378 DOI: 10.3390/ijms24054528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 02/11/2023] [Accepted: 02/21/2023] [Indexed: 03/03/2023] Open
Abstract
Pore-forming proteins (PFPs) play a central role in many biological processes related to infection, immunity, cancer, and neurodegeneration. A common feature of PFPs is their ability to form pores that disrupt the membrane permeability barrier and ion homeostasis and generally induce cell death. Some PFPs are part of the genetically encoded machinery of eukaryotic cells that are activated against infection by pathogens or in physiological programs to carry out regulated cell death. PFPs organize into supramolecular transmembrane complexes that perforate membranes through a multistep process involving membrane insertion, protein oligomerization, and finally pore formation. However, the exact mechanism of pore formation varies from PFP to PFP, resulting in different pore structures with different functionalities. Here, we review recent insights into the molecular mechanisms by which PFPs permeabilize membranes and recent methodological advances in their characterization in artificial and cellular membranes. In particular, we focus on single-molecule imaging techniques as powerful tools to unravel the molecular mechanistic details of pore assembly that are often obscured by ensemble measurements, and to determine pore structure and functionality. Uncovering the mechanistic elements of pore formation is critical for understanding the physiological role of PFPs and developing therapeutic approaches.
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Zhou AXZ, Hammond JA, Sheng K, Millar DP, Williamson JR. Early HIV-1 Gag Assembly on Lipid Membrane with vRNA. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.27.525415. [PMID: 36747785 PMCID: PMC9901173 DOI: 10.1101/2023.01.27.525415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Mass photometry (MP) was used to investigate the assembly of myristoylated full-length HIV-1 Gag (myr-Gag) and vRNA 5’ UTR fragment in a supported lipid bilayer (SLB) model system. The MP trajectories demonstrated that Gag trimerization on the membrane is a key step of early Gag assembly in the presence of vRNA. Growth of myr-Gag oligomers requires vRNA, occuring by addition of 1 or 2 monomers at a time from solution. These data support a model where formation of the Gag hexamers characteristic of the immature capsid lattice occurs by a gradual edge expansion, following a trimeric nucleation event. These dynamic single molecule data involving protein, RNA, and lipid components together, provide novel and fundamental insights into the initiation of virus capsid assembly.
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Zhou X, Wang R, Wan Z, Zhang P, Wang S. Multiplexed Protein Detection and Parallel Binding Kinetics Analysis with Label-Free Digital Single-Molecule Counting. Anal Chem 2023; 95:1541-1548. [PMID: 36595491 PMCID: PMC10316747 DOI: 10.1021/acs.analchem.2c04582] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Multiplexed protein detection is critical for improving the drug and biomarker screening efficiency. Here, we show that multiplexed protein detection and parallel protein interaction analysis can be realized by evanescent scattering microscopy (ESM). ESM enables binding kinetics measurement with label-free digital single-molecule counting. We implemented an automatic single-molecule counting strategy with high temporal resolution to precisely determine the binding time, which improves the counting efficiency and accuracy. We show that digital single-molecule counting can recognize proteins with different molecular weights, thus making it possible to monitor the protein binding processes in the solution by real-time tracking of the numbers of free and bound proteins landing on the sensor surface. Furthermore, we show that this strategy can simultaneously analyze the kinetics of two different protein interaction processes on the surface and in the solution. This work may pave a way to investigate complicated protein interactions, such as the competition of biomarker-antibody binding in biofluids with biomarker-protein binding on the cellular membrane.
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Affiliation(s)
- Xinyu Zhou
- Biodesign Center for Bioelectronics and Biosensors, Arizona State University, Tempe, Arizona 85287, USA
- School of Biological and Health Systems Engineering, Arizona State University, Tempe, Arizona 85287, USA
| | - Rui Wang
- Biodesign Center for Bioelectronics and Biosensors, Arizona State University, Tempe, Arizona 85287, USA
| | - Zijian Wan
- Biodesign Center for Bioelectronics and Biosensors, Arizona State University, Tempe, Arizona 85287, USA
- School of Electrical, Energy and Computer Engineering, Arizona State University, Tempe, Arizona 85287, USA
| | - Pengfei Zhang
- Biodesign Center for Bioelectronics and Biosensors, Arizona State University, Tempe, Arizona 85287, USA
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Shaopeng Wang
- Biodesign Center for Bioelectronics and Biosensors, Arizona State University, Tempe, Arizona 85287, USA
- School of Biological and Health Systems Engineering, Arizona State University, Tempe, Arizona 85287, USA
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ATPase Activity of Bacillus subtilis RecA Affects the Dynamic Formation of RecA Filaments at DNA Double Strand Breaks. mSphere 2022; 7:e0041222. [PMID: 36321831 PMCID: PMC9769622 DOI: 10.1128/msphere.00412-22] [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] [Indexed: 12/24/2022] Open
Abstract
RecA plays a central role in DNA repair and is a main actor involved in homologous recombination (HR). In vivo, RecA forms filamentous structures termed "threads," which are essential for HR, but whose nature is still ill defined. We show that RecA from Bacillus subtilis having lower ATP binding activity can still form nucleoprotein filaments in vitro, features lower dsDNA binding activity, but still retains most of wild type RecA activity in vivo. Contrarily, loss of ATPase activity strongly reduced formation of nucleoprotein filaments in vitro, and effectivity to repair double strand breaks (DSBs) in vivo. In the presence of wild type RecA protein, additionally expressed RecA with lowered ATPbinding activity only moderately affected RecA dynamics, while loss of ATPase activity leads to a large reduction of the formation of threads, as well as of their dynamic changes observed in a seconds-scale. Single molecule tracking of RecA revealed incorporation of freely diffusing and nonspecifically DNA-bound molecules into threads upon induction of a single DSB. This change of dynamics was highly perturbed in the absence of ATPase activity, revealing that filamentous forms of RecA as well as their dynamics depend on ATPase activity. Based on the idea that ATPase activity of RecA is most important for DNA strand exchange activity, our data suggest that extension and retraction of threads due is to many local strand invasion events during the search for sequences homologous to the induced DNA break site. IMPORTANCE Single-strand (ss) DNA binding ATPase RecA is the central recombinase in homologous recombination, and therefore essential for DNA repair pathways involving DNA strand exchange reactions. In several bacterial, RecA forms filamentous structures along the long axis of cells after induction of double strand breaks (DSBs) in the chromosome. These striking assemblies likely reflect RecA/ssDNA nucleoprotein filaments, which can extend and remodel within a time frame of few minutes. We show that ATPase activity of RecA is pivotal for these dynamic rearrangements, which include recruitment of freely diffusing molecules into low-mobile molecules within filaments. Our data suggest that ssDNA binding- and unbinding reactions are at the heart of RecA dynamics that power the dynamics of subcellular filamentous assemblies, leading to strand exchange reactions over a distance of several micrometers.
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Liu L, Tibbs J, Li N, Bacon A, Shepherd S, Lee H, Chauhan N, Demirci U, Wang X, Cunningham BT. A Photonic Resonator Interferometric Scattering Microscope for Label-free Detection of Nanometer-Scale Objects with Digital Precision in Point-of-Use Environments. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2022:2022.12.13.520266. [PMID: 36561182 PMCID: PMC9774210 DOI: 10.1101/2022.12.13.520266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Label-free detection and digital counting of nanometer-scaled objects such as nanoparticles, viruses, extracellular vesicles, and protein molecules enable a wide range of applications in cancer diagnostics, pathogen detection, and life science research. The contrast of interferometric scattering microscopy is amplified through a photonic crystal surface, upon which scattered light from an object combines with illumination from a monochromatic plane wave source. The use of a photonic crystal substrate for interference scattering microscopy results in reduced requirements for high-intensity lasers or oil-immersion objectives, thus opening a pathway toward instruments that are more suitable for environments outside the optics laboratory. Here, we report the design, implementation, and characterization of a compact Photonic Resonator Interferometric Scattering Microscope (PRISM) designed for point-of-use environments and applications. The instrument incorporates two innovative elements that facilitate operation on a desktop in ordinary laboratory environments by users that do not have optics expertise. First, because scattering microscopes are extremely sensitive to vibration, we incorporated an inexpensive but effective solution of suspending the instrument's main components from a rigid metal framework using elastic bands, resulting in an average of 28.7 dBV reduction in vibration amplitude compared to an office desk. Second, an automated focusing module based on the principle of total internal reflection maintains the stability of image contrast over time and spatial position, facilitating automated data collection. In this work, we characterize the system's performance by measuring the contrast from gold nanoparticles with diameters in the 10-40 nm range and by observing various biological analytes, including HIV virus, SARS-CoV-2 virus, exosomes, and ferritin protein.
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Affiliation(s)
- Leyang Liu
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Nick Holonyak Jr. Micro and Nanotechnology Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Joseph Tibbs
- Nick Holonyak Jr. Micro and Nanotechnology Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Nantao Li
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Nick Holonyak Jr. Micro and Nanotechnology Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Amanda Bacon
- Nick Holonyak Jr. Micro and Nanotechnology Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Skye Shepherd
- Nick Holonyak Jr. Micro and Nanotechnology Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Hankeun Lee
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Nick Holonyak Jr. Micro and Nanotechnology Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Neha Chauhan
- Nick Holonyak Jr. Micro and Nanotechnology Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Utkan Demirci
- Canary Center at Stanford for Cancer Early Detection, Stanford School of Medicine, Stanford University, Palo Alto, California 94304, USA
| | - Xing Wang
- Nick Holonyak Jr. Micro and Nanotechnology Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Brian T. Cunningham
- Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Nick Holonyak Jr. Micro and Nanotechnology Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
- Cancer Center at Illinois, Urbana, Illinois 61801, USA
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Rao D, Yan T, Qiao Z, Wang Y, Peng Y, Tu H, Wu S, Zhang Q. Relay-type sensing mode: A strategy to push the limit on nanomechanical sensor sensitivity based on the magneto lever. NANO RESEARCH 2022; 16:3231-3239. [PMID: 36405983 PMCID: PMC9661467 DOI: 10.1007/s12274-022-5049-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 09/04/2022] [Accepted: 09/14/2022] [Indexed: 06/16/2023]
Abstract
UNLABELLED Ultrasensitive molecular detection and quantization are crucial for many applications including clinical diagnostics, functional proteomics, and drug discovery; however, conventional biochemical sensors cannot satisfy the stringent requirements, and this has resulted in a long-standing dilemma regarding sensitivity improvement. To this end, we have developed an ultrasensitive relay-type nanomechanical sensor based on a magneto lever. By establishing the link between very weak molecular interaction and five orders of magnitude larger magnetic force, analytes at ultratrace level can produce a clearly observable mechanical response. Initially, proof-of-concept studies showed an improved detection limit up to five orders of magnitude when employing the magneto lever, as compared with direct detection using probe alone. In this study, we subsequently demonstrated that the relay-type sensing mode was universal in application ranging from micromolecule to macromolecule detection, which can be easily extended to detect enzymes, DNA, proteins, cells, viruses, bacteria, chemicals, etc. Importantly, we found that, sensitivity was no longer subject to probe affinity when the magneto lever was sufficiently high, theoretically, even reaching single-molecule resolution. ELECTRONIC SUPPLEMENTARY MATERIAL Supplementary material (experimental section) is available in the online version of this article at 10.1007/s12274-022-5049-0.
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Affiliation(s)
- Depeng Rao
- CAS Key Laboratory of Mechanical Behavior and Design of Material, Department of Modern Mechanics, University of Science and Technology of China, Hefei, 230027 China
| | - Tianhao Yan
- CAS Key Laboratory of Mechanical Behavior and Design of Material, Department of Modern Mechanics, University of Science and Technology of China, Hefei, 230027 China
| | - Zihan Qiao
- CAS Key Laboratory of Mechanical Behavior and Design of Material, Department of Modern Mechanics, University of Science and Technology of China, Hefei, 230027 China
| | - Yu Wang
- CAS Key Laboratory of Mechanical Behavior and Design of Material, Department of Modern Mechanics, University of Science and Technology of China, Hefei, 230027 China
| | - Yongpei Peng
- CAS Key Laboratory of Mechanical Behavior and Design of Material, Department of Modern Mechanics, University of Science and Technology of China, Hefei, 230027 China
| | - Han Tu
- CAS Key Laboratory of Mechanical Behavior and Design of Material, Department of Modern Mechanics, University of Science and Technology of China, Hefei, 230027 China
| | - Shangquan Wu
- CAS Key Laboratory of Mechanical Behavior and Design of Material, Department of Modern Mechanics, University of Science and Technology of China, Hefei, 230027 China
| | - Qingchuan Zhang
- CAS Key Laboratory of Mechanical Behavior and Design of Material, Department of Modern Mechanics, University of Science and Technology of China, Hefei, 230027 China
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38
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Lavania A, Carpenter WB, Oltrogge LM, Perez D, Turnšek JB, Savage DF, Moerner WE. Exploring Masses and Internal Mass Distributions of Single Carboxysomes in Free Solution Using Fluorescence and Interferometric Scattering in an Anti-Brownian Trap. J Phys Chem B 2022; 126:8747-8759. [PMID: 36282790 PMCID: PMC9639131 DOI: 10.1021/acs.jpcb.2c05939] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 10/10/2022] [Indexed: 01/11/2023]
Abstract
Carboxysomes are self-assembled bacterial microcompartments that facilitate carbon assimilation by colocalizing the enzymes of CO2 fixation within a protein shell. These microcompartments can be highly heterogeneous in their composition and filling, so measuring the mass and loading of an individual carboxysome would allow for better characterization of its assembly and function. To enable detailed and extended characterizations of single nanoparticles in solution, we recently demonstrated an improved interferometric scattering anti-Brownian electrokinetic (ISABEL) trap, which tracks the position of a single nanoparticle via its scattering of a near-infrared beam and applies feedback to counteract its Brownian motion. Importantly, the scattering signal can be related to the mass of nanoscale proteinaceous objects, whose refractive indices are well-characterized. We calibrate single-particle scattering cross-section measurements in the ISABEL trap and determine individual carboxysome masses in the 50-400 MDa range by analyzing their scattering cross sections with a core-shell model. We further investigate carboxysome loading by combining mass measurements with simultaneous fluorescence reporting from labeled internal components. This method may be extended to other biological objects, such as viruses or extracellular vesicles, and can be combined with orthogonal fluorescence reporters to achieve precise physical and chemical characterization of individual nanoscale biological objects.
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Affiliation(s)
- Abhijit
A. Lavania
- Department
of Chemistry, Stanford University, Stanford, California94305, United States
- Department
of Applied Physics, Stanford University, Stanford, California94305, United States
| | - William B. Carpenter
- Department
of Chemistry, Stanford University, Stanford, California94305, United States
| | - Luke M. Oltrogge
- Department
of Molecular and Cell Biology, University
of California Berkeley, Berkeley, California94720, United States
| | - Davis Perez
- Department
of Chemistry, Stanford University, Stanford, California94305, United States
| | - Julia B. Turnšek
- Department
of Molecular and Cell Biology, University
of California Berkeley, Berkeley, California94720, United States
| | - David F. Savage
- Department
of Molecular and Cell Biology, University
of California Berkeley, Berkeley, California94720, United States
| | - W. E. Moerner
- Department
of Chemistry, Stanford University, Stanford, California94305, United States
- Department
of Applied Physics, Stanford University, Stanford, California94305, United States
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39
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Ding L, Shan X, Wang D, Liu B, Du Z, Di X, Chen C, Maddahfar M, Zhang L, Shi Y, Reece P, Halkon B, Aharonovich I, Xu X, Wang F. Lanthanide Ion Resonance-Driven Rayleigh Scattering of Nanoparticles for Dual-Modality Interferometric Scattering Microscopy. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2203354. [PMID: 35975425 PMCID: PMC9661846 DOI: 10.1002/advs.202203354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Indexed: 06/15/2023]
Abstract
Light scattering from nanoparticles is significant in nanoscale imaging, photon confinement. and biosensing. However, engineering the scattering spectrum, traditionally by modifying the geometric feature of particles, requires synthesis and fabrication with nanometre accuracy. Here it is reported that doping lanthanide ions can engineer the scattering properties of low-refractive-index nanoparticles. When the excitation wavelength matches the ion resonance frequency of lanthanide ions, the polarizability and the resulted scattering cross-section of nanoparticles are dramatically enhanced. It is demonstrated that these purposely engineered nanoparticles can be used for interferometric scattering (iSCAT) microscopy. Conceptually, a dual-modality iSCAT microscopy is further developed to identify different nanoparticle types in living HeLa cells. The work provides insight into engineering the scattering features by doping elements in nanomaterials, further inspiring exploration of the geometry-independent scattering modulation strategy.
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Affiliation(s)
- Lei Ding
- School of Mathematical and Physical SciencesFaculty of ScienceUniversity of Technology SydneyUltimoNew South Wales2007Australia
- School of Electrical and Data EngineeringFaculty of Engineering and Information TechnologyUniversity of Technology SydneyUltimoNew South Wales2007Australia
| | - Xuchen Shan
- School of Mathematical and Physical SciencesFaculty of ScienceUniversity of Technology SydneyUltimoNew South Wales2007Australia
- School of Electrical and Data EngineeringFaculty of Engineering and Information TechnologyUniversity of Technology SydneyUltimoNew South Wales2007Australia
- School of PhysicsBeihang UniversityBeijing100191China
| | - Dejiang Wang
- School of Mathematical and Physical SciencesFaculty of ScienceUniversity of Technology SydneyUltimoNew South Wales2007Australia
| | - Baolei Liu
- School of PhysicsBeihang UniversityBeijing100191China
| | - Ziqing Du
- School of Mathematical and Physical SciencesFaculty of ScienceUniversity of Technology SydneyUltimoNew South Wales2007Australia
| | - Xiangjun Di
- School of Mathematical and Physical SciencesFaculty of ScienceUniversity of Technology SydneyUltimoNew South Wales2007Australia
| | - Chaohao Chen
- School of Electrical and Data EngineeringFaculty of Engineering and Information TechnologyUniversity of Technology SydneyUltimoNew South Wales2007Australia
| | - Mahnaz Maddahfar
- School of Mathematical and Physical SciencesFaculty of ScienceUniversity of Technology SydneyUltimoNew South Wales2007Australia
| | - Ling Zhang
- School of Electrical and Data EngineeringFaculty of Engineering and Information TechnologyUniversity of Technology SydneyUltimoNew South Wales2007Australia
| | - Yuzhi Shi
- National Key Laboratory of Science and Technology on Micro/Nano FabricationDepartment of Micro/Nano ElectronicsShanghai Jiao Tong UniversityShanghai200240P. R. China
| | - Peter Reece
- School of PhysicsThe University of New South WalesKensingtonNew South Wales2033Australia
| | - Benjamin Halkon
- Centre for Audio, Acoustics & VibrationFaculty of Engineering & ITUniversity of Technology SydneyUltimoNew South Wales2007Australia
| | - Igor Aharonovich
- School of Mathematical and Physical SciencesFaculty of ScienceUniversity of Technology SydneyUltimoNew South Wales2007Australia
- ARC Centre of Excellence for Transformative Meta‐Optical Systems (TMOS)Faculty of ScienceUniversity of Technology SydneyUltimoNew South Wales2007Australia
| | - Xiaoxue Xu
- School of Biomedical Engineering, Faculty of Engineering and Information TechnologyUniversity of Technology SydneyUltimoNew South Wales2007Australia
| | - Fan Wang
- School of Electrical and Data EngineeringFaculty of Engineering and Information TechnologyUniversity of Technology SydneyUltimoNew South Wales2007Australia
- School of PhysicsBeihang UniversityBeijing100191China
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40
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Ding Y, Xing D, Fei Y, Lu B. Emerging degrader technologies engaging lysosomal pathways. Chem Soc Rev 2022; 51:8832-8876. [PMID: 36218065 PMCID: PMC9620493 DOI: 10.1039/d2cs00624c] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Indexed: 08/24/2023]
Abstract
Targeted protein degradation (TPD) provides unprecedented opportunities for drug discovery. While the proteolysis-targeting chimera (PROTAC) technology has already entered clinical trials and changed the landscape of small-molecule drugs, new degrader technologies harnessing alternative degradation machineries, especially lysosomal pathways, have emerged and broadened the spectrum of degradable targets. We have recently proposed the concept of autophagy-tethering compounds (ATTECs) that hijack the autophagy protein microtubule-associated protein 1A/1B light chain 3 (LC3) for targeted degradation. Other groups also reported degrader technologies engaging lysosomal pathways through different mechanisms including AUTACs, AUTOTACs, LYTACs and MoDE-As. In this review, we analyse and discuss ATTECs along with other lysosomal-relevant degrader technologies. Finally, we will briefly summarize the current status of these degrader technologies and envision possible future studies.
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Affiliation(s)
- Yu Ding
- Neurology Department at Huashan Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, School of Life Sciences, Fudan University, Shanghai, China.
| | - Dong Xing
- Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, China.
| | - Yiyan Fei
- Department of Optical Science and Engineering, Shanghai Engineering Research Center of Ultra-Precision Optical Manufacturing, Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Fudan University, Shanghai, China.
| | - Boxun Lu
- Neurology Department at Huashan Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, School of Life Sciences, Fudan University, Shanghai, China.
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41
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Imoto Y, Raychaudhuri S, Ma Y, Fenske P, Sandoval E, Itoh K, Blumrich EM, Matsubayashi HT, Mamer L, Zarebidaki F, Söhl-Kielczynski B, Trimbuch T, Nayak S, Iwasa JH, Liu J, Wu B, Ha T, Inoue T, Jorgensen EM, Cousin MA, Rosenmund C, Watanabe S. Dynamin is primed at endocytic sites for ultrafast endocytosis. Neuron 2022; 110:2815-2835.e13. [PMID: 35809574 PMCID: PMC9464723 DOI: 10.1016/j.neuron.2022.06.010] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 03/24/2022] [Accepted: 06/09/2022] [Indexed: 02/06/2023]
Abstract
Dynamin mediates fission of vesicles from the plasma membrane during endocytosis. Typically, dynamin is recruited from the cytosol to endocytic sites, requiring seconds to tens of seconds. However, ultrafast endocytosis in neurons internalizes vesicles as quickly as 50 ms during synaptic vesicle recycling. Here, we demonstrate that Dynamin 1 is pre-recruited to endocytic sites for ultrafast endocytosis. Specifically, Dynamin 1xA, a splice variant of Dynamin 1, interacts with Syndapin 1 to form molecular condensates on the plasma membrane. Single-particle tracking of Dynamin 1xA molecules confirms the liquid-like property of condensates in vivo. When Dynamin 1xA is mutated to disrupt its interaction with Syndapin 1, the condensates do not form, and consequently, ultrafast endocytosis slows down by 100-fold. Mechanistically, Syndapin 1 acts as an adaptor by binding the plasma membrane and stores Dynamin 1xA at endocytic sites. This cache bypasses the recruitment step and accelerates endocytosis at synapses.
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Affiliation(s)
- Yuuta Imoto
- Department of Cell Biology, Johns Hopkins University, Baltimore, MD 21205, USA.
| | - Sumana Raychaudhuri
- Department of Cell Biology, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Ye Ma
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Pascal Fenske
- Institute of Neurophysiology, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Eduardo Sandoval
- Department of Cell Biology, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Kie Itoh
- Department of Cell Biology, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Eva-Maria Blumrich
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, Scotland EH8 9XD, UK; The Muir Maxwell Epilepsy Centre, University of Edinburgh, Edinburgh, Scotland EH8 9XD, UK; Simons Initiatives for the Developing Brain, University of Edinburgh, Edinburgh, Scotland EH8 9XD, UK
| | - Hideaki T Matsubayashi
- Department of Cell Biology, Johns Hopkins University, Baltimore, MD 21205, USA; The Center for Cell Dynamics, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Lauren Mamer
- Institute of Neurophysiology, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Fereshteh Zarebidaki
- Institute of Neurophysiology, Charité Universitätsmedizin Berlin, Berlin, Germany
| | | | - Thorsten Trimbuch
- Institute of Neurophysiology, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Shraddha Nayak
- Department of Biochemistry, University of Utah, Salt Lake City, UT 84112-0840, USA
| | - Janet H Iwasa
- Department of Biochemistry, University of Utah, Salt Lake City, UT 84112-0840, USA
| | - Jian Liu
- Department of Cell Biology, Johns Hopkins University, Baltimore, MD 21205, USA; Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, Scotland EH8 9XD, UK
| | - Bin Wu
- The Center for Cell Dynamics, Johns Hopkins University, Baltimore, MD 21205, USA; Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD 21205, USA; Department of Biophysics and Biophysical Chemistry, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Taekjip Ha
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21205, USA; Department of Biophysics and Biophysical Chemistry, Johns Hopkins University, Baltimore, MD 21205, USA; Howard Hughes Medical Institute, Baltimore, MD 21205, USA
| | - Takanari Inoue
- Department of Cell Biology, Johns Hopkins University, Baltimore, MD 21205, USA; The Center for Cell Dynamics, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Erik M Jorgensen
- HHMI, Department of Biology, University of Utah, Salt Lake City, UT 84112-0840, USA
| | - Michael A Cousin
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, Scotland EH8 9XD, UK; The Muir Maxwell Epilepsy Centre, University of Edinburgh, Edinburgh, Scotland EH8 9XD, UK; Simons Initiatives for the Developing Brain, University of Edinburgh, Edinburgh, Scotland EH8 9XD, UK
| | - Christian Rosenmund
- Institute of Neurophysiology, Charité Universitätsmedizin Berlin, Berlin, Germany.
| | - Shigeki Watanabe
- Department of Cell Biology, Johns Hopkins University, Baltimore, MD 21205, USA; The Center for Cell Dynamics, Johns Hopkins University, Baltimore, MD 21205, USA; Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, MD 21205, USA.
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Zhang P, Wang R, Wan Z, Zhou X, Ma G, Kolay J, Jiang J, Wang S. Label-Free Imaging of Single Proteins and Binding Kinetics Using Total Internal Reflection-Based Evanescent Scattering Microscopy. Anal Chem 2022; 94:10781-10787. [PMID: 35852494 PMCID: PMC9467297 DOI: 10.1021/acs.analchem.2c01510] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Single-molecule detection can push beyond ensemble averages and reveal the statistical distributions of molecular properties. Measuring the binding kinetics of single proteins also represents one of the critical and challenging tasks in protein analysis. Here, we report total internal reflection-based evanescent scattering microscopy with label-free single-protein detection capability. Total internal reflection is employed to excite the evanescent field to enhance light-analyte interaction and reduce environmental noise. As a result, the system provides wide-field imaging capability and allows excitation and observation using one objective. In addition, this system quantifies protein binding kinetics by simultaneously counting the binding of individual molecules and recording their binding sites with nanometer precision, providing a digital method to measure binding kinetics with high spatiotemporal resolution. This approach does not employ specially designed microspheres or nanomaterials and may pave a way for label-free single-protein analysis in conventional microscopy.
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Affiliation(s)
- Pengfei Zhang
- Biodesign Center for Bioelectronics and Biosensors, Arizona State University, Tempe, Arizona 85287, United States
| | - Rui Wang
- Biodesign Center for Bioelectronics and Biosensors, Arizona State University, Tempe, Arizona 85287, United States
| | - Zijian Wan
- Biodesign Center for Bioelectronics and Biosensors, Arizona State University, Tempe, Arizona 85287, United States
- School of Electrical, Energy and Computer Engineering, Arizona State University, Tempe, Arizona 85287, United States
| | - Xinyu Zhou
- Biodesign Center for Bioelectronics and Biosensors, Arizona State University, Tempe, Arizona 85287, United States
- School of Biological and Health Systems Engineering, Arizona State University, Tempe, Arizona 85287, United States
| | - Guangzhong Ma
- Biodesign Center for Bioelectronics and Biosensors, Arizona State University, Tempe, Arizona 85287, United States
| | - Jayeeta Kolay
- Biodesign Center for Bioelectronics and Biosensors, Arizona State University, Tempe, Arizona 85287, United States
| | - Jiapei Jiang
- Biodesign Center for Bioelectronics and Biosensors, Arizona State University, Tempe, Arizona 85287, United States
- School of Biological and Health Systems Engineering, Arizona State University, Tempe, Arizona 85287, United States
| | - Shaopeng Wang
- Biodesign Center for Bioelectronics and Biosensors, Arizona State University, Tempe, Arizona 85287, United States
- School of Biological and Health Systems Engineering, Arizona State University, Tempe, Arizona 85287, United States
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43
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Characterising biomolecular interactions and dynamics with mass photometry. Curr Opin Chem Biol 2022; 68:102132. [DOI: 10.1016/j.cbpa.2022.102132] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 02/22/2022] [Indexed: 12/25/2022]
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44
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Label-free nanofluidic scattering microscopy of size and mass of single diffusing molecules and nanoparticles. Nat Methods 2022; 19:751-758. [PMID: 35637303 PMCID: PMC9184284 DOI: 10.1038/s41592-022-01491-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 04/12/2022] [Indexed: 12/18/2022]
Abstract
Label-free characterization of single biomolecules aims to complement fluorescence microscopy in situations where labeling compromises data interpretation, is technically challenging or even impossible. However, existing methods require the investigated species to bind to a surface to be visible, thereby leaving a large fraction of analytes undetected. Here, we present nanofluidic scattering microscopy (NSM), which overcomes these limitations by enabling label-free, real-time imaging of single biomolecules diffusing inside a nanofluidic channel. NSM facilitates accurate determination of molecular weight from the measured optical contrast and of the hydrodynamic radius from the measured diffusivity, from which information about the conformational state can be inferred. Furthermore, we demonstrate its applicability to the analysis of a complex biofluid, using conditioned cell culture medium containing extracellular vesicles as an example. We foresee the application of NSM to monitor conformational changes, aggregation and interactions of single biomolecules, and to analyze single-cell secretomes. Nanofluidic scattering microscopy enables label-free, quantitative measurements of the molecular weight and hydrodynamic radius of biological molecules and nanoparticles freely diffusing inside a nanofluidic channel.
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45
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Hsiao YT, Tsai CN, Chen TH, Hsieh CL. Label-Free Dynamic Imaging of Chromatin in Live Cell Nuclei by High-Speed Scattering-Based Interference Microscopy. ACS NANO 2022; 16:2774-2788. [PMID: 34967599 DOI: 10.1021/acsnano.1c09748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Chromatin is a DNA-protein complex that is densely packed in the cell nucleus. The nanoscale chromatin compaction plays critical roles in the modulation of cell nuclear processes. However, little is known about the spatiotemporal dynamics of chromatin compaction states because it remains difficult to quantitatively measure the chromatin compaction level in live cells. Here, we demonstrate a strategy, referenced as DYNAMICS imaging, for mapping chromatin organization in live cell nuclei by analyzing the dynamic scattering signal of molecular fluctuations. Highly sensitive optical interference microscopy, coherent brightfield (COBRI) microscopy, is implemented to detect the linear scattering of unlabeled chromatin at a high speed. A theoretical model is established to determine the local chromatin density from the statistical fluctuation of the measured scattering signal. DYNAMICS imaging allows us to reconstruct a speckle-free nucleus map that is highly correlated to the fluorescence chromatin image. Moreover, together with calibration based on nanoparticle colloids, we show that the DYNAMICS signal is sensitive to the chromatin compaction level at the nanoscale. We confirm the effectiveness of DYNAMICS imaging in detecting the condensation and decondensation of chromatin induced by chemical drug treatments. Importantly, the stable scattering signal supports a continuous observation of the chromatin condensation and decondensation processes for more than 1 h. Using this technique, we detect transient and nanoscopic chromatin condensation events occurring on a time scale of a few seconds. Label-free DYNAMICS imaging offers the opportunity to investigate chromatin conformational dynamics and to explore their significance in various gene activities.
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Affiliation(s)
- Yi-Teng Hsiao
- Institute of Atomic and Molecular Sciences (IAMS), Academia Sinica, 1 Roosevelt Road Section 4, Taipei 10617, Taiwan
| | - Chia-Ni Tsai
- Institute of Atomic and Molecular Sciences (IAMS), Academia Sinica, 1 Roosevelt Road Section 4, Taipei 10617, Taiwan
| | - Te-Hsin Chen
- Institute of Atomic and Molecular Sciences (IAMS), Academia Sinica, 1 Roosevelt Road Section 4, Taipei 10617, Taiwan
| | - Chia-Lung Hsieh
- Institute of Atomic and Molecular Sciences (IAMS), Academia Sinica, 1 Roosevelt Road Section 4, Taipei 10617, Taiwan
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46
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Priest L, Peters JS, Kukura P. Scattering-based Light Microscopy: From Metal Nanoparticles to Single Proteins. Chem Rev 2021; 121:11937-11970. [PMID: 34587448 PMCID: PMC8517954 DOI: 10.1021/acs.chemrev.1c00271] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Indexed: 02/02/2023]
Abstract
Our ability to detect, image, and quantify nanoscopic objects and molecules with visible light has undergone dramatic improvements over the past few decades. While fluorescence has historically been the go-to contrast mechanism for ultrasensitive light microscopy due to its superior background suppression and specificity, recent developments based on light scattering have reached single-molecule sensitivity. They also have the advantages of universal applicability and the ability to obtain information about the species of interest beyond its presence and location. Many of the recent advances are driven by novel approaches to illumination, detection, and background suppression, all aimed at isolating and maximizing the signal of interest. Here, we review these developments grouped according to the basic principles used, namely darkfield imaging, interferometric detection, and surface plasmon resonance microscopy.
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Affiliation(s)
| | | | - Philipp Kukura
- Physical and Theoretical
Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom
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47
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Vala M, Piliarik M. Weighing single protein complexes on the go. Nat Methods 2021; 18:1159-1160. [PMID: 34608317 DOI: 10.1038/s41592-021-01263-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Milan Vala
- Institute of Photonics and Electronics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Marek Piliarik
- Institute of Photonics and Electronics of the Czech Academy of Sciences, Prague, Czech Republic.
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