1
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Zheng H, Munusamy S, Arora P, Jahani R, Guan X. A highly sensitive nanopore platform for measuring RNase A activity. Talanta 2024; 276:126276. [PMID: 38796995 PMCID: PMC11187776 DOI: 10.1016/j.talanta.2024.126276] [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: 03/20/2024] [Revised: 05/11/2024] [Accepted: 05/16/2024] [Indexed: 05/29/2024]
Abstract
Ribonuclease A (RNase A) plays significant roles in several physiological and pathological conditions and can be used as a valuable diagnostic biomarker for human diseases such as myocardial infarction and cancer. Hence, it is of great importance to develop a rapid and cost-effective method for the highly sensitive detection of RNase A. The significance of RNase A assay is further enhanced by the growing attention from the biotechnology and pharmaceutical industries to develop RNA-based vaccines and drugs in large part as a result of the successful development of mRNA vaccines in the COVID-19 pandemic. Herein, we report a label-free method for the detection of RNase A by monitoring its proteolytic cleavage of an RNA substrate in a nanopore. The method is ultra-sensitive with the limit of detection reaching as low as 30 fg per milliliter. Furthermore, sensor selectivity and the effects of temperature, incubation time, metal ion, salt concentration on sensor sensitivity were also investigated.
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Affiliation(s)
- Haiyan Zheng
- Department of Chemistry, University of Missouri, Columbia, MO 65211, USA
| | | | - Pearl Arora
- Department of Chemistry, Illinois Institute of Technology, Chicago, IL, 60616, USA
| | - Rana Jahani
- Department of Chemistry, University of Missouri, Columbia, MO 65211, USA
| | - Xiyun Guan
- Department of Chemistry, University of Missouri, Columbia, MO 65211, USA.
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2
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Deb R, Torres MDT, Boudný M, Koběrská M, Cappiello F, Popper M, Dvořáková Bendová K, Drabinová M, Hanáčková A, Jeannot K, Petřík M, Mangoni ML, Balíková Novotná G, Mráz M, de la Fuente-Nunez C, Vácha R. Computational Design of Pore-Forming Peptides with Potent Antimicrobial and Anticancer Activities. J Med Chem 2024. [PMID: 39116273 DOI: 10.1021/acs.jmedchem.4c00912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/10/2024]
Abstract
Peptides that form transmembrane barrel-stave pores are potential alternative therapeutics for bacterial infections and cancer. However, their optimization for clinical translation is hampered by a lack of sequence-function understanding. Recently, we have de novo designed the first synthetic barrel-stave pore-forming antimicrobial peptide with an identified function of all residues. Here, we systematically mutate the peptide to improve pore-forming ability in anticipation of enhanced activity. Using computer simulations, supported by liposome leakage and atomic force microscopy experiments, we find that pore-forming ability, while critical, is not the limiting factor for improving activity in the submicromolar range. Affinity for bacterial and cancer cell membranes needs to be optimized simultaneously. Optimized peptides more effectively killed antibiotic-resistant ESKAPEE bacteria at submicromolar concentrations, showing low cytotoxicity to human cells and skin model. Peptides showed systemic anti-infective activity in a preclinical mouse model of Acinetobacter baumannii infection. We also demonstrate peptide optimization for pH-dependent antimicrobial and anticancer activity.
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Affiliation(s)
- Rahul Deb
- CEITEC - Central European Institute of Technology, Masaryk University, Brno 625 00, Czech Republic
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno 625 00, Czech Republic
| | - Marcelo D T Torres
- Machine Biology Group, Departments of Psychiatry and Microbiology, Institute for Biomedical Informatics, Institute for Translational Medicine and Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Departments of Bioengineering and Chemical and Biomolecular Engineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Penn Institute for Computational Science, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Miroslav Boudný
- CEITEC - Central European Institute of Technology, Masaryk University, Brno 625 00, Czech Republic
- Department of Internal Medicine, Hematology and Oncology, University Hospital Brno and Faculty of Medicine, Masaryk University, Brno 625 00, Czech Republic
| | - Markéta Koběrská
- Institute of Microbiology, Czech Academy of Sciences, BIOCEV, Vestec 252 50, Czech Republic
| | - Floriana Cappiello
- Department of Biochemical Sciences, Laboratory Affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza University of Rome, Rome 00185, Italy
| | - Miroslav Popper
- Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacký University, Olomouc 779 00, Czech Republic
| | - Kateřina Dvořáková Bendová
- Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacký University, Olomouc 779 00, Czech Republic
| | - Martina Drabinová
- CEITEC - Central European Institute of Technology, Masaryk University, Brno 625 00, Czech Republic
| | - Adelheid Hanáčková
- CEITEC - Central European Institute of Technology, Masaryk University, Brno 625 00, Czech Republic
| | - Katy Jeannot
- University of Franche-Comté, CNRS, Chrono-environment, Besançon 25030, France
- National Reference Centre for Antibiotic Resistance, Besançon 25030, France
| | - Miloš Petřík
- Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacký University, Olomouc 779 00, Czech Republic
- Czech Advanced Technology and Research Institute, Palacký University, Olomouc 779 00, Czech Republic
| | - Maria Luisa Mangoni
- Department of Biochemical Sciences, Laboratory Affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza University of Rome, Rome 00185, Italy
| | | | - Marek Mráz
- CEITEC - Central European Institute of Technology, Masaryk University, Brno 625 00, Czech Republic
- Department of Internal Medicine, Hematology and Oncology, University Hospital Brno and Faculty of Medicine, Masaryk University, Brno 625 00, Czech Republic
| | - Cesar de la Fuente-Nunez
- Machine Biology Group, Departments of Psychiatry and Microbiology, Institute for Biomedical Informatics, Institute for Translational Medicine and Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Departments of Bioengineering and Chemical and Biomolecular Engineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Penn Institute for Computational Science, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Robert Vácha
- CEITEC - Central European Institute of Technology, Masaryk University, Brno 625 00, Czech Republic
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno 625 00, Czech Republic
- Department of Condensed Matter Physics, Faculty of Science, Masaryk University, Brno 611 37, Czech Republic
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3
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Krishnan R S, Firzan Ca N, Mahendran KR. Functionally Active Synthetic α-Helical Pores. Acc Chem Res 2024; 57:1790-1802. [PMID: 38875523 DOI: 10.1021/acs.accounts.4c00101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2024]
Abstract
ConspectusTransmembrane pores are currently at the forefront of nanobiotechnology, nanopore chemistry, and synthetic chemical biology research. Over the past few decades, significant studies in protein engineering have paved the way for redesigning membrane protein pores tailored for specific applications in nanobiotechnology. Most previous efforts predominantly centered on natural β-barrel pores designed with atomic precision for nucleic acid sequencing and sensing of biomacromolecules, including protein fragments. The requirement for a more efficient single-molecule detection system has driven the development of synthetic nanopores. For example, engineering channels to conduct ions and biomolecules selectively could lead to sophisticated nanopore sensors. Also, there has been an increased interest in synthetic pores, which can be fabricated to provide more control in designing architecture and diameter for single-molecule sensing of complex biomacromolecules. There have been impressive advancements in developing synthetic DNA-based pores, although their application in nanopore technology is limited. This has prompted a significant shift toward building synthetic transmembrane α-helical pores, a relatively underexplored field offering novel opportunities. Recently, computational tools have been employed to design and construct α-helical barrels of defined structure and functionality.We focus on building synthetic α-helical pores using naturally occurring transmembrane motifs of membrane protein pores. Our laboratory has developed synthetic α-helical transmembrane pores based on the natural porin PorACj (Porin A derived from Corynebacterium jeikeium) that function as nanopore sensors for single-molecule sensing of cationic cyclodextrins and polypeptides. Our breakthrough lies in being the first to create a functional and large stable synthetic transmembrane pore composed of short synthetic α-helical peptides. The key highlight of our work is that these pores can be synthesized using easy chemical synthesis, which permits its easy modification to include a variety of functional groups to build charge-selective sophisticated pores. Additionally, we have demonstrated that stable functional pores can be constructed from D-amino acid peptides. The analysis of pores composed of D- and L-amino acids in the presence of protease showed that only the D pores are highly functional and stable. The structural models of these pores revealed distinct surface charge conformation and geometry. These new classes of synthetic α-helical pores are highly original systems of general interest due to their unique architecture, functionality, and potential applications in nanopore technology and chemical biology. We emphasize that these simplified transmembrane pores have the potential to be components of functional nanodevices and therapeutic tools. We also suggest that such designed peptides might be valuable as antimicrobial agents and can be targeted to cancer cells. This article will focus on the evolutions in assembling α-helical transmembrane pores and highlight their advantages, including structural and functional versatility.
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Affiliation(s)
- Smrithi Krishnan R
- Transdisciplinary Research Program, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, India-695014
| | - Neilah Firzan Ca
- Transdisciplinary Research Program, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, India-695014
- Manipal Academy of Higher Education, Manipal, Karnataka India-576104
| | - Kozhinjampara R Mahendran
- Transdisciplinary Research Program, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, India-695014
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4
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Zhang X, Malle MG, Thomsen RP, Sørensen RS, Sørensen EW, Hatzakis NS, Kjems J. Deconvoluting the Effect of Cell-Penetrating Peptides for Enhanced and Controlled Insertion of Large-Scale DNA Nanopores. ACS APPLIED MATERIALS & INTERFACES 2024; 16:18422-18433. [PMID: 38573069 DOI: 10.1021/acsami.3c18636] [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: 04/05/2024]
Abstract
DNA nanopores have emerged as powerful tools for molecular sensing, but the efficient insertion of large DNA nanopores into lipid membranes remains challenging. In this study, we investigate the potential of cell-penetrating peptides (CPPs), specifically SynB1 and GALA, to enhance the insertion efficiency of large DNA nanopores. We constructed SynB1- or GALA-functionalized DNA nanopores with an 11 nm inner diameter and visualized and quantified their membrane insertion using a TIRF microscopy-based single-liposome assay. The results demonstrated that incorporating an increasing number of SynB1 or GALA peptides into the DNA nanopore significantly enhanced the membrane perforation. Kinetic analysis revealed that the DNA nanopore scaffold played a role in prearranging the CPPs, which facilitated membrane interaction and pore formation. Notably, the use of pH-responsive GALA peptides allowed highly efficient and pH-controlled insertion of large DNA pores. Furthermore, single-channel recording elucidated that the insertion process of single GALA-modified nanopores into planar lipid bilayers was dynamic, likely forming transient large toroidal pores. Overall, our study highlights the potential of CPPs as insertion enhancers for DNA nanopores, which opens avenues for improved molecule sensing and the controlled release of cargo molecules.
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Affiliation(s)
- Xialin Zhang
- Interdisciplinary Nanoscience Center, Aarhus University, Aarhus C 8000, Denmark
| | | | - Rasmus P Thomsen
- Interdisciplinary Nanoscience Center, Aarhus University, Aarhus C 8000, Denmark
| | | | | | - Nikos S Hatzakis
- Department of Chemistry, University of Copenhagen, Copenhagen 2100, Denmark
- Novonordisk Center for Protein Research, University of Copenhagen, Copenhagen 2100, Denmark
| | - Jørgen Kjems
- Interdisciplinary Nanoscience Center, Aarhus University, Aarhus C 8000, Denmark
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus C 8000, Denmark
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5
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Dash MK, Joshi N, Dwivedi L, Dubey VS, Dwivedi KN. Characterization of lead sulfide obtained from Naga Bhasma. J Ayurveda Integr Med 2024; 15:100864. [PMID: 38527393 PMCID: PMC10979094 DOI: 10.1016/j.jaim.2023.100864] [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: 02/04/2022] [Revised: 08/23/2023] [Accepted: 12/06/2023] [Indexed: 03/27/2024] Open
Abstract
BACKGROUND Lead sulfide nanoparticles were manufactured from lead oxide using a procedure described in the Ayurveda formulary of India, which involved using a quantum of the heat of up to 60 puta, which is officially known as the Shasti puta Naga Bhasma. OBJECTIVE The study shows sulfurization of nanoparticles decreased their toxicity due to the lower solubility. MATERIALS AND METHODS The present work used the arsenic sulfide media and traditional puta for processing and the characterization of the same has been conducted. Different analytical techniques like X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-Ray (EDX) spectroscopy, Fourier transform infrared spectroscopy (FTIR), and thermo-gravimetry analysis (TGA) were used. RESULTS Powder x-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, Thermogravimetric analysis, and differential thermal analysis all showed that the produced nanoparticles are lead sulfide nanoparticles with a particle size of an average of 84.60 and the crystalline average size of 69.06 nm. CONCLUSION The rounded, rod, oval, cubic, and circular morphology of the produced lead sulfide nanoparticles can be seen in the SEM image. The stretching and bending functional groups in the sample were alkanes, alkenes, aromatic hydrocarbons, carboxylic acids, alkyl carboxylic acids, alkyl alpha, beta-unsaturated, aldehydes, ketones, carboxylic acid, aliphatic amines, primary amines, secondary amines, alkyl halides, are studied through the FTIR spectrum.
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Affiliation(s)
- Manoj Kumar Dash
- Dept. of Rasashastra, Govt. Ayurveda College, Raipur, C.G, India.
| | - Namrata Joshi
- Dept. of Rasashastra, Faculty of Ayurveda, IMS, Banaras Hindu University, Varanasi, 221005, India
| | | | - Vd Sushil Dubey
- Dept. of Kriya Sarira, Faculty of Ayurveda, IMS, BHU, Varanasi, India
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6
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Guan X, Shao W, Zhang D. T-S2Inet: Transformer-based sequence-to-image network for accurate nanopore sequence recognition. Bioinformatics 2024; 40:btae083. [PMID: 38366607 PMCID: PMC10902682 DOI: 10.1093/bioinformatics/btae083] [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: 10/28/2023] [Revised: 02/01/2024] [Accepted: 02/13/2024] [Indexed: 02/18/2024] Open
Abstract
MOTIVATION Nanopore sequencing is a new macromolecular recognition and perception technology that enables high-throughput sequencing of DNA, RNA, even protein molecules. The sequences generated by nanopore sequencing span a large time frame, and the labor and time costs incurred by traditional analysis methods are substantial. Recently, research on nanopore data analysis using machine learning algorithms has gained unceasing momentum, but there is often a significant gap between traditional and deep learning methods in terms of classification results. To analyze nanopore data using deep learning technologies, measures such as sequence completion and sequence transformation can be employed. However, these technologies do not preserve the local features of the sequences. To address this issue, we propose a sequence-to-image (S2I) module that transforms sequences of unequal length into images. Additionally, we propose the Transformer-based T-S2Inet model to capture the important information and improve the classification accuracy. RESULTS Quantitative and qualitative analysis shows that the experimental results have an improvement of around 2% in accuracy compared to previous methods. The proposed method is adaptable to other nanopore platforms, such as the Oxford nanopore. It is worth noting that the proposed method not only aims to achieve the most advanced performance, but also provides a general idea for the analysis of nanopore sequences of unequal length. AVAILABILITY AND IMPLEMENTATION The main program is available at https://github.com/guanxiaoyu11/S2Inet.
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Affiliation(s)
- Xiaoyu Guan
- College of Computer Science and Technology, Nanjing University of Aeronautics and Astronautics, MIIT Key Laboratory of Pattern Analysis and Machine Intelligence, Nanjing 211106, China
- Key Laboratory of Brain-Machine Intelligence Technology, Ministry of Education, Nanjing University of Aeronautics and Astronautics, Nanjing 211106, China
| | - Wei Shao
- College of Computer Science and Technology, Nanjing University of Aeronautics and Astronautics, MIIT Key Laboratory of Pattern Analysis and Machine Intelligence, Nanjing 211106, China
- Key Laboratory of Brain-Machine Intelligence Technology, Ministry of Education, Nanjing University of Aeronautics and Astronautics, Nanjing 211106, China
| | - Daoqiang Zhang
- College of Computer Science and Technology, Nanjing University of Aeronautics and Astronautics, MIIT Key Laboratory of Pattern Analysis and Machine Intelligence, Nanjing 211106, China
- Key Laboratory of Brain-Machine Intelligence Technology, Ministry of Education, Nanjing University of Aeronautics and Astronautics, Nanjing 211106, China
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7
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Dolorfino M, Samanta R, Vorobieva A. ProteinMPNN Recovers Complex Sequence Properties of Transmembrane β-barrels. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.16.575764. [PMID: 38352434 PMCID: PMC10862708 DOI: 10.1101/2024.01.16.575764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/19/2024]
Abstract
Recent deep-learning (DL) protein design methods have been successfully applied to a range of protein design problems, including the de novo design of novel folds, protein binders, and enzymes. However, DL methods have yet to meet the challenge of de novo membrane protein (MP) and the design of complex β-sheet folds. We performed a comprehensive benchmark of one DL protein sequence design method, ProteinMPNN, using transmembrane and water-soluble β-barrel folds as a model, and compared the performance of ProteinMPNN to the new membrane-specific Rosetta Franklin2023 energy function. We tested the effect of input backbone refinement on ProteinMPNN performance and found that given refined and well-defined inputs, ProteinMPNN more accurately captures global sequence properties despite complex folding biophysics. It generates more diverse TMB sequences than Franklin2023 in pore-facing positions. In addition, ProteinMPNN generated TMB sequences that passed state-of-the-art in silico filters for experimental validation, suggesting that the model could be used in de novo design tasks of diverse nanopores for single-molecule sensing and sequencing. Lastly, our results indicate that the low success rate of ProteinMPNN for the design of β-sheet proteins stems from backbone input accuracy rather than software limitations.
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Affiliation(s)
- Marissa Dolorfino
- Structural Biology Brussel, Vrije Universiteit Brussel, Brussels, Belgium
- VUB-VIB Center for Structural Biology, Brussels, Belgium
| | | | - Anastassia Vorobieva
- Structural Biology Brussel, Vrije Universiteit Brussel, Brussels, Belgium
- VUB-VIB Center for Structural Biology, Brussels, Belgium
- VIB Center for AI and Computational Biology, Belgium
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8
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Ojha AA, Votapka LW, Amaro RE. QMrebind: incorporating quantum mechanical force field reparameterization at the ligand binding site for improved drug-target kinetics through milestoning simulations. Chem Sci 2023; 14:13159-13175. [PMID: 38023523 PMCID: PMC10664576 DOI: 10.1039/d3sc04195f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Accepted: 10/22/2023] [Indexed: 12/01/2023] Open
Abstract
Understanding the interaction of ligands with biomolecules is an integral component of drug discovery and development. Challenges for computing thermodynamic and kinetic quantities for pharmaceutically relevant receptor-ligand complexes include the size and flexibility of the ligands, large-scale conformational rearrangements of the receptor, accurate force field parameters, simulation efficiency, and sufficient sampling associated with rare events. Our recently developed multiscale milestoning simulation approach, SEEKR2 (Simulation Enabled Estimation of Kinetic Rates v.2), has demonstrated success in predicting unbinding (koff) kinetics by employing molecular dynamics (MD) simulations in regions closer to the binding site. The MD region is further subdivided into smaller Voronoi tessellations to improve the simulation efficiency and parallelization. To date, all MD simulations are run using general molecular mechanics (MM) force fields. The accuracy of calculations can be further improved by incorporating quantum mechanical (QM) methods into generating system-specific force fields through reparameterizing ligand partial charges in the bound state. The force field reparameterization process modifies the potential energy landscape of the bimolecular complex, enabling a more accurate representation of the intermolecular interactions and polarization effects at the bound state. We present QMrebind (Quantum Mechanical force field reparameterization at the receptor-ligand binding site), an ORCA-based software that facilitates reparameterizing the potential energy function within the phase space representing the bound state in a receptor-ligand complex. With SEEKR2 koff estimates and experimentally determined kinetic rates, we compare and interpret the receptor-ligand unbinding kinetics obtained using the newly reparameterized force fields for model host-guest systems and HSP90-inhibitor complexes. This method provides an opportunity to achieve higher accuracy in predicting receptor-ligand koff rate constants.
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Affiliation(s)
- Anupam Anand Ojha
- Department of Chemistry and Biochemistry, University of California San Diego La Jolla California 92093 USA
| | - Lane William Votapka
- Department of Chemistry and Biochemistry, University of California San Diego La Jolla California 92093 USA
| | - Rommie Elizabeth Amaro
- Department of Molecular Biology, University of California San Diego La Jolla California 92093 USA
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9
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Müller W, Beales PA, Muniz AR, Jeuken LJC. Unraveling the Phase Behavior, Mechanical Stability, and Protein Reconstitution Properties of Polymer-Lipid Hybrid Vesicles. Biomacromolecules 2023; 24:4156-4169. [PMID: 37539954 PMCID: PMC10498451 DOI: 10.1021/acs.biomac.3c00498] [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: 05/17/2023] [Revised: 07/20/2023] [Indexed: 08/05/2023]
Abstract
Hybrid vesicles consisting of natural phospholipids and synthetic amphiphilic copolymers have shown remarkable material properties and potential for biotechnology, combining the robustness of polymers with the biocompatibility of phospholipid membranes. To predict and optimize the mixing behavior of lipids and copolymers, as well as understand the interaction between the hybrid membrane and macromolecules like membrane proteins, a comprehensive understanding at the molecular level is essential. This can be achieved by a combination of molecular dynamics simulations and experiments. Here, simulations of POPC and PBD22-b-PEO14 hybrid membranes are shown, uncovering different copolymer configurations depending on the polymer-to-lipid ratio. High polymer concentrations created thicker membranes with an extended polymer conformation, while high lipid content led to the collapse of the polymer chain. High concentrations of polymer were further correlated with a decreased area compression modulus and altered lateral pressure profiles, hypothesized to result in the experimentally observed improvement in membrane protein reconstitution and resistance toward destabilization by detergents. Finally, simulations of a WALP peptide embedded in the bilayer showed that only membranes with up to 50% polymer content favored a transmembrane configuration. These simulations correlate with previous and new experimental results and provide a deeper understanding of the properties of lipid-copolymer hybrid membranes.
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Affiliation(s)
- Wagner
A. Müller
- Department
of Chemical Engineering, Universidade Federal
do Rio Grande do Sul, Porto
Alegre 90035-003, Brazil
| | - Paul A. Beales
- School
of Chemistry and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, U.K.
| | - André R. Muniz
- Department
of Chemical Engineering, Universidade Federal
do Rio Grande do Sul, Porto
Alegre 90035-003, Brazil
| | - Lars J. C. Jeuken
- Leiden
Institute of Chemistry, University Leiden, PO Box 9502, 2300RA Leiden, The
Netherlands
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10
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Xing Y, Rottensteiner A, Ciccone J, Howorka S. Functional Nanopores Enabled with DNA. Angew Chem Int Ed Engl 2023; 62:e202303103. [PMID: 37186432 DOI: 10.1002/anie.202303103] [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: 03/01/2023] [Revised: 04/20/2023] [Accepted: 04/21/2023] [Indexed: 05/17/2023]
Abstract
Membrane-spanning nanopores are used in label-free single-molecule sensing and next-generation portable nucleic acid sequencing, and as powerful research tools in biology, biophysics, and synthetic biology. Naturally occurring protein and peptide pores, as well as synthetic inorganic nanopores, are used in these applications, with their limitations. The structural and functional repertoire of nanopores can be considerably expanded by functionalising existing pores with DNA strands and by creating an entirely new class of nanopores with DNA nanotechnology. This review outlines progress in this area of functional DNA nanopores and outlines developments to open up new applications.
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Affiliation(s)
- Yongzheng Xing
- Department of Chemistry, Institute for Structural and Molecular Biology, University College London, London, WC1H 0AJ, UK
| | - Alexia Rottensteiner
- Department of Chemistry, Institute for Structural and Molecular Biology, University College London, London, WC1H 0AJ, UK
| | - Jonah Ciccone
- Department of Chemistry, Institute for Structural and Molecular Biology, University College London, London, WC1H 0AJ, UK
| | - Stefan Howorka
- Department of Chemistry, Institute for Structural and Molecular Biology, University College London, London, WC1H 0AJ, UK
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11
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Seneviratne R, Coates G, Xu Z, Cornell CE, Thompson RF, Sadeghpour A, Maskell DP, Jeuken LJC, Rappolt M, Beales PA. High Resolution Membrane Structures within Hybrid Lipid-Polymer Vesicles Revealed by Combining X-Ray Scattering and Electron Microscopy. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2206267. [PMID: 36866488 DOI: 10.1002/smll.202206267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 01/26/2023] [Indexed: 06/02/2023]
Abstract
Hybrid vesicles consisting of phospholipids and block-copolymers are increasingly finding applications in science and technology. Herein, small angle X-ray scattering (SAXS) and cryo-electron tomography (cryo-ET) are used to obtain detailed structural information about hybrid vesicles with different ratios of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and poly(1,2-butadiene-block-ethylene oxide) (PBd22 -PEO14 , Ms = 1800 g mol-1 ). Using single particle analysis (SPA) the authors are able to further interpret the information gained from SAXS and cryo-ET experiments, showing that increasing PBd22 -PEO14 mole fraction increases the membrane thickness from 52 Å for a pure lipid system to 97 Å for pure PBd22 -PEO14 vesicles. Two vesicle populations with different membrane thicknesses in hybrid vesicle samples are found. As these lipids and polymers are reported to homogeneously mix, bistability is inferred between weak and strong interdigitation regimes of PBd22 -PEO14 within the hybrid membranes. It is hypothesized that membranes of intermediate structure are not energetically favorable. Therefore, each vesicle exists in one of these two membrane structures, which are assumed to have comparable free energies. The authors conclude that, by combining biophysical methods, accurate determination of the influence of composition on the structural properties of hybrid membranes is achieved, revealing that two distinct membranes structures can coexist in homogeneously mixed lipid-polymer hybrid vesicles.
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Affiliation(s)
- Rashmi Seneviratne
- School of Chemistry and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK
| | - Georgina Coates
- School of Chemistry and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK
| | - Zexi Xu
- School of Food Science and Nutrition, School of Chemistry and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK
| | - Caitlin E Cornell
- Department of Bioengineering, University of California, Berkeley, CA, 94720, USA
| | - Rebecca F Thompson
- School of Molecular and Cellular Biology and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK
| | - Amin Sadeghpour
- School of Food Science and Nutrition, University of Leeds, Leeds, LS2 9JT, UK
| | - Daniel P Maskell
- School of Molecular and Cellular Biology and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK
| | - Lars J C Jeuken
- Leiden Institute of Chemistry, Leiden University, PC Box 9502, Leiden, 2300 RA, Netherlands
| | - Michael Rappolt
- School of Food Science and Nutrition, University of Leeds, Leeds, LS2 9JT, UK
| | - Paul A Beales
- School of Chemistry and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, LS2 9JT, UK
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12
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Sajeer P M. Disruptive technology: Exploring the ethical, legal, political, and societal implications of nanopore sequencing technology: Exploring the ethical, legal, political, and societal implications of nanopore sequencing technology. EMBO Rep 2023; 24:e56619. [PMID: 36988424 PMCID: PMC10157308 DOI: 10.15252/embr.202256619] [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: 12/07/2022] [Revised: 02/16/2023] [Accepted: 03/16/2023] [Indexed: 03/30/2023] Open
Abstract
Due to its low cost and easy handling, nanopore sequencing has great potential to become a consumer product. The widespread use of DNA sequencers would, however, create new social, legal, and ethical challenges.
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Affiliation(s)
- Muhammad Sajeer P
- Center for Nanoscience and EngineeringIndian Institute of ScienceBangaloreIndia
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13
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Zhang L, Burns N, Ji Z, Sun S, Deutscher SL, Carson WE, Guo P. Nipple fluid for breast cancer diagnosis using the nanopore of Phi29 DNA-packaging motor. NANOMEDICINE : NANOTECHNOLOGY, BIOLOGY, AND MEDICINE 2023; 48:102642. [PMID: 36581256 PMCID: PMC10035634 DOI: 10.1016/j.nano.2022.102642] [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: 09/28/2022] [Revised: 11/14/2022] [Accepted: 12/02/2022] [Indexed: 12/27/2022]
Abstract
Detection of cancer in its early stage is a challenging task for oncologists. Inflammatory breast cancer has symptoms that are similar to mastitis and can be mistaken for microbial infection. Currently, the differential diagnosis between mastitis and Inflammatory breast cancer via nipple aspirate fluid (NAF) is difficult. Here, we report a label-free and amplification-free detection platform using an engineered nanopore of the phi29 DNA-packaging motor with biomarker Galectin3 (GAL3), Thomsen-Friedenreich (TF) binding peptide as the probe fused at its C-terminus. The binding of the biomarker in NAF samples from breast cancer patients to the probe results in the connector's conformational change with a current blockage of 32 %. Utilization of dwell time, blockage ratio, and peak signature enable us to detect basal levels of biomarkers from patient NAF samples at the single-molecule level. This platform will allow for breast cancers to be resolved at an early stage with accuracy and thoroughness.
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Affiliation(s)
- Long Zhang
- Center for RNA Nanobiotechnology and Nanomedicine, College of Pharmacy, Dorothy M. Davis Heart and Lung Research Institute, James Comprehensive Cancer Center, College of Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Nicolas Burns
- Center for RNA Nanobiotechnology and Nanomedicine, College of Pharmacy, Dorothy M. Davis Heart and Lung Research Institute, James Comprehensive Cancer Center, College of Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Zhouxiang Ji
- Center for RNA Nanobiotechnology and Nanomedicine, College of Pharmacy, Dorothy M. Davis Heart and Lung Research Institute, James Comprehensive Cancer Center, College of Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Steven Sun
- OSU Comprehensive Cancer Center, The Ohio State University, Columbus, OH 43210, USA
| | - Susan L Deutscher
- Department of Biochemistry, University of Missouri, Harry S. Truman Memorial VA Hospital, Columbia, MO 65211, USA.
| | - William E Carson
- OSU Comprehensive Cancer Center, The Ohio State University, Columbus, OH 43210, USA.
| | - Peixuan Guo
- Center for RNA Nanobiotechnology and Nanomedicine, College of Pharmacy, Dorothy M. Davis Heart and Lung Research Institute, James Comprehensive Cancer Center, College of Medicine, The Ohio State University, Columbus, OH 43210, USA.
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14
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Guan X, Li Z, Zhou Y, Shao W, Zhang D. Active learning for efficient analysis of high-throughput nanopore data. Bioinformatics 2022; 39:6851141. [PMID: 36445037 PMCID: PMC9825740 DOI: 10.1093/bioinformatics/btac764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 10/25/2022] [Accepted: 11/28/2022] [Indexed: 11/30/2022] Open
Abstract
MOTIVATION As the third-generation sequencing technology, nanopore sequencing has been used for high-throughput sequencing of DNA, RNA, and even proteins. Recently, many studies have begun to use machine learning technology to analyze the enormous data generated by nanopores. Unfortunately, the success of this technology is due to the extensive labeled data, which often suffer from enormous labor costs. Therefore, there is an urgent need for a novel technology that can not only rapidly analyze nanopore data with high-throughput, but also significantly reduce the cost of labeling. To achieve the above goals, we introduce active learning to alleviate the enormous labor costs by selecting the samples that need to be labeled. This work applies several advanced active learning technologies to the nanopore data, including the RNA classification dataset (RNA-CD) and the Oxford Nanopore Technologies barcode dataset (ONT-BD). Due to the complexity of the nanopore data (with noise sequence), the bias constraint is introduced to improve the sample selection strategy in active learning. Results: The experimental results show that for the same performance metric, 50% labeling amount can achieve the best baseline performance for ONT-BD, while only 15% labeling amount can achieve the best baseline performance for RNA-CD. Crucially, the experiments show that active learning technology can assist experts in labeling samples, and significantly reduce the labeling cost. Active learning can greatly reduce the dilemma of difficult labeling of high-capacity nanopore data. We hope active learning can be applied to other problems in nanopore sequence analysis. AVAILABILITY AND IMPLEMENTATION The main program is available at https://github.com/guanxiaoyu11/AL-for-nanopore. SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- Xiaoyu Guan
- College of Computer Science and Technology, Nanjing University of Aeronautics and Astronautics, MIIT Key Laboratory of Pattern Analysis and Machine Intelligence, Nanjing 211106, China
| | - Zhongnian Li
- College of Computer Science and Technology, Nanjing University of Aeronautics and Astronautics, MIIT Key Laboratory of Pattern Analysis and Machine Intelligence, Nanjing 211106, China,School of Computer Science, China University of Mining Technology, Xuzhou 221116, China
| | - Yueying Zhou
- College of Computer Science and Technology, Nanjing University of Aeronautics and Astronautics, MIIT Key Laboratory of Pattern Analysis and Machine Intelligence, Nanjing 211106, China
| | - Wei Shao
- College of Computer Science and Technology, Nanjing University of Aeronautics and Astronautics, MIIT Key Laboratory of Pattern Analysis and Machine Intelligence, Nanjing 211106, China
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15
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Singh A, Maity A, Singh N. Structure and Dynamics of dsDNA in Cell-like Environments. ENTROPY (BASEL, SWITZERLAND) 2022; 24:1587. [PMID: 36359677 PMCID: PMC9689892 DOI: 10.3390/e24111587] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2022] [Revised: 10/28/2022] [Accepted: 10/31/2022] [Indexed: 06/01/2023]
Abstract
Deoxyribonucleic acid (DNA) is a fundamental biomolecule for correct cellular functioning and regulation of biological processes. DNA's structure is dynamic and has the ability to adopt a variety of structural conformations in addition to its most widely known double-stranded DNA (dsDNA) helix structure. Stability and structural dynamics of dsDNA play an important role in molecular biology. In vivo, DNA molecules are folded in a tightly confined space, such as a cell chamber or a channel, and are highly dense in solution; their conformational properties are restricted, which affects their thermodynamics and mechanical properties. There are also many technical medical purposes for which DNA is placed in a confined space, such as gene therapy, DNA encapsulation, DNA mapping, etc. Physiological conditions and the nature of confined spaces have a significant influence on the opening or denaturation of DNA base pairs. In this review, we summarize the progress of research on the stability and dynamics of dsDNA in cell-like environments and discuss current challenges and future directions. We include studies on various thermal and mechanical properties of dsDNA in ionic solutions, molecular crowded environments, and confined spaces. By providing a better understanding of melting and unzipping of dsDNA in different environments, this review provides valuable guidelines for predicting DNA thermodynamic quantities and for designing DNA/RNA nanostructures.
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16
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Muhammad Sajeer P, Simran, Nukala P, Manoj M. Varma. TEM based applications in solid state nanopores: From fabrication to liquid in-situ bio-imaging. Micron 2022; 162:103347. [DOI: 10.1016/j.micron.2022.103347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Revised: 08/23/2022] [Accepted: 08/23/2022] [Indexed: 10/31/2022]
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17
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Cao Z, Yadav P, Barati Farimani A. Which 2D Material is Better for DNA Detection: Graphene, MoS 2, or MXene? NANO LETTERS 2022; 22:7874-7881. [PMID: 36165777 DOI: 10.1021/acs.nanolett.2c02603] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Despite much research on characterizing 2D materials for DNA detection with nanopore technology, a thorough comparison between the performance of different 2D materials is currently lacking. In this work, using extensive molecular dynamics simulations, we compare nanoporous graphene, MoS2 and titanium carbide MXene (Ti3C2) for their DNA detection performance and sensitivity. The ionic current and residence time of DNA are characterized in each nanoporous materials by performing hundreds of simulations. We devised two statistical measures including the Kolmogorov-Smirnov test and the absolute pairwise difference to compare the performance of nanopores. We found that graphene nanopore is the most sensitive membrane for distinguishing DNA bases. The MoS2 is capable of distinguishing the A and T bases from the C and G bases better than graphene and MXene. Physisorption and the orientation of DNA in nanopores are further investigated to provide molecular insight into the performance characteristics of different nanopores.
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Affiliation(s)
- Zhonglin Cao
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Prakarsh Yadav
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Amir Barati Farimani
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
- Department of Chemical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
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18
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Qing R, Hao S, Smorodina E, Jin D, Zalevsky A, Zhang S. Protein Design: From the Aspect of Water Solubility and Stability. Chem Rev 2022; 122:14085-14179. [PMID: 35921495 PMCID: PMC9523718 DOI: 10.1021/acs.chemrev.1c00757] [Citation(s) in RCA: 54] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Indexed: 12/13/2022]
Abstract
Water solubility and structural stability are key merits for proteins defined by the primary sequence and 3D-conformation. Their manipulation represents important aspects of the protein design field that relies on the accurate placement of amino acids and molecular interactions, guided by underlying physiochemical principles. Emulated designer proteins with well-defined properties both fuel the knowledge-base for more precise computational design models and are used in various biomedical and nanotechnological applications. The continuous developments in protein science, increasing computing power, new algorithms, and characterization techniques provide sophisticated toolkits for solubility design beyond guess work. In this review, we summarize recent advances in the protein design field with respect to water solubility and structural stability. After introducing fundamental design rules, we discuss the transmembrane protein solubilization and de novo transmembrane protein design. Traditional strategies to enhance protein solubility and structural stability are introduced. The designs of stable protein complexes and high-order assemblies are covered. Computational methodologies behind these endeavors, including structure prediction programs, machine learning algorithms, and specialty software dedicated to the evaluation of protein solubility and aggregation, are discussed. The findings and opportunities for Cryo-EM are presented. This review provides an overview of significant progress and prospects in accurate protein design for solubility and stability.
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Affiliation(s)
- Rui Qing
- State
Key Laboratory of Microbial Metabolism, School of Life Sciences and
Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
- Media
Lab, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
- The
David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Shilei Hao
- Media
Lab, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
- Key
Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400030, China
| | - Eva Smorodina
- Department
of Immunology, University of Oslo and Oslo
University Hospital, Oslo 0424, Norway
| | - David Jin
- Avalon GloboCare
Corp., Freehold, New Jersey 07728, United States
| | - Arthur Zalevsky
- Laboratory
of Bioinformatics Approaches in Combinatorial Chemistry and Biology, Shemyakin−Ovchinnikov Institute of Bioorganic
Chemistry RAS, Moscow 117997, Russia
| | - Shuguang Zhang
- Media
Lab, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
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19
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Yang L, Hu J, Li MC, Xu M, Gu ZY. Solid-state nanopore: chemical modifications, interactions, and functionalities. Chem Asian J 2022; 17:e202200775. [PMID: 36071031 DOI: 10.1002/asia.202200775] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 09/06/2022] [Indexed: 11/08/2022]
Abstract
Nanopore technology is a burgeoning detection technology for single-molecular sensing and ion rectification. Solid-state nanopores have attracted more and more attention because of their higher stability and tunability than biological nanopores. However, solid-state nanopores still suffer the drawbacks of low signal-to-noise ratio and low resolution, which hinders their practical applications. Thus, developing operatical and useful methods to overcome the shortages of solid-state nanopores is urgently needed. Here, we summarize the recent research on nanopore modification to achieve this goal. Modifying solid-state nanopores with different coating molecules can improve the selectivity, sensitivity, and stability of nanopores. The modified molecules can introduce different functions into the nanopores, greatly expanding the applications of this novel detection technology. We hope that this review of nanopore modification will provide new ideas for this field.
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Affiliation(s)
- Lei Yang
- Nanjing Normal University, College of Chemistry and Materials Science, CHINA
| | - Jun Hu
- Nanjing Normal University, College of Chemistry and Materials Science, CHINA
| | - Min-Chao Li
- Nanjing Normal University, College of Chemistry and Materials Science, CHINA
| | - Ming Xu
- Nanjing Normal University, College of Chemistry and Materials Science, CHINA
| | - Zhi-Yuan Gu
- Nanjing Normal University, College of Chemistry and Materials Science, 1 Wenyuan Rd, 210023, Nanjing, CHINA
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20
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Solov'eva TF, Bakholdina SI, Khomenko VA, Sidorin EV, Kim NY, Novikova OD, Shnyrov VL, Stenkova AM, Eremeev VI, Bystritskaya EP, Isaeva MP. Expression of membrane beta-barrel protein in E. coli at low temperatures: Structure of Yersinia pseudotuberculosis OmpF porin inclusion bodies. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2022; 1864:183971. [PMID: 35643329 DOI: 10.1016/j.bbamem.2022.183971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Revised: 04/14/2022] [Accepted: 05/19/2022] [Indexed: 06/15/2023]
Abstract
The recombinant OmpF porin of Yersinia pseudotuberculosis as a model of transmembrane protein of the β-barrel structural family was used to study low growth temperature effect on the structure of the produced inclusion bodies (IBs). This porin showed a very low expression level in E. coli at a growth temperature below optimal 37 °C. The introduction of a N-terminal hexahistidine tag into the mature porin molecule significantly increased the biosynthesis of the protein at low cultivation temperatures. The recombinant His-tagged porin (rOmpF-His) was expressed in E. coli at 30 and 18 °C as inclusion bodies (IB-30 and IB-18). The properties and structural organization of IBs, as well as the structure of rOmpF-His solubilized from the IBs with urea and SDS, were studied using turbidimetry, electron microscopy, dynamic light scattering, optical spectroscopy, and amyloid-specific dyes. IB-18, in comparison with IB-30, has a higher solubility in denaturants, suggesting a difference between IBs in the conformation of the associated polypeptide chains. The spectroscopic analysis revealed that rOmpF-His IBs have a high content of secondary structure with a tertiary-structure elements, including a native-like conformation, the proportion of which in IB-18 is higher than in IB-30. Solubilization of the porin from IBs is accompanied by a modification of its secondary structure. The studied IBs also contain amyloid-like structures. The results obtained in this study expand our knowledge of the structural organization of IBs formed by proteins of different structural classes and also have a contribution into the new approaches development of producing functionally active recombinant membrane proteins.
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Affiliation(s)
- Tamara F Solov'eva
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far-Eastern Branch of the Russian Academy of Sciences, Prospekt 100-let Vladivostoku 159, 690022 Vladivostok, Russia
| | - Svetlana I Bakholdina
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far-Eastern Branch of the Russian Academy of Sciences, Prospekt 100-let Vladivostoku 159, 690022 Vladivostok, Russia.
| | - Valentina A Khomenko
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far-Eastern Branch of the Russian Academy of Sciences, Prospekt 100-let Vladivostoku 159, 690022 Vladivostok, Russia
| | - Evgeniy V Sidorin
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far-Eastern Branch of the Russian Academy of Sciences, Prospekt 100-let Vladivostoku 159, 690022 Vladivostok, Russia
| | - Natalya Yu Kim
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far-Eastern Branch of the Russian Academy of Sciences, Prospekt 100-let Vladivostoku 159, 690022 Vladivostok, Russia
| | - Olga D Novikova
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far-Eastern Branch of the Russian Academy of Sciences, Prospekt 100-let Vladivostoku 159, 690022 Vladivostok, Russia
| | - Valery L Shnyrov
- Departamento de Bioquimica y Biologia Molecular, Universidad de Salamanca, Plaza Doctores de la Reina s/n, 37007 Salamanca, Spain
| | - Anna M Stenkova
- Far Eastern Federal University School of Biomedicine, Russky Island Ajax Bay 10, 690922 Vladivostok, Russia
| | - Vyacheslav I Eremeev
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far-Eastern Branch of the Russian Academy of Sciences, Prospekt 100-let Vladivostoku 159, 690022 Vladivostok, Russia
| | - Evgenia P Bystritskaya
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far-Eastern Branch of the Russian Academy of Sciences, Prospekt 100-let Vladivostoku 159, 690022 Vladivostok, Russia
| | - Marina P Isaeva
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far-Eastern Branch of the Russian Academy of Sciences, Prospekt 100-let Vladivostoku 159, 690022 Vladivostok, Russia
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21
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Probing the Hepatitis B Virus E-Antigen with a Nanopore Sensor Based on Collisional Events Analysis. BIOSENSORS 2022; 12:bios12080596. [PMID: 36004992 PMCID: PMC9405897 DOI: 10.3390/bios12080596] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 07/29/2022] [Accepted: 08/03/2022] [Indexed: 11/24/2022]
Abstract
Real-time monitoring, simple operation, and cheaper methods for detecting immunological proteins hold the potential for a solid influence on proteomics and human biology, as they can promote the onset of timely diagnoses and adequate treatment protocols. In this work we present an exploratory study suggesting the applicability of resistive-pulse sensing technology in conjunction with the α-hemolysin (α-HL) protein nanopore, for the detection of the chronic hepatitis B virus (HBV) e-antigen (HBeAg). In this approach, the recognition between HBeAg and a purified monoclonal hepatitis B e antibody (Ab(HBeAg)) was detected via transient ionic current spikes generated by partial occlusions of the α-HL nanopore by protein aggregates electrophoretically driven toward the nanopore’s vestibule entrance. Despite the steric hindrance precluding antigen, antibody, or antigen–antibody complex capture inside the nanopore, their stochastic bumping with the nanopore generated clear transient blockade events. The subsequent analysis suggested the detection of protein subpopulations in solution, rendering the approach a potentially valuable label-free platform for the sensitive, submicromolar-scale screening of HBeAg targets.
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22
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Xing Y, Dorey A, Jayasinghe L, Howorka S. Highly shape- and size-tunable membrane nanopores made with DNA. NATURE NANOTECHNOLOGY 2022; 17:708-713. [PMID: 35484212 DOI: 10.1038/s41565-022-01116-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 03/10/2022] [Indexed: 06/14/2023]
Abstract
Membrane nanopores are key for molecular transport in biology, portable DNA sequencing1-4, label-free single-molecule analysis5-14 and nanomedicine5. Transport traditionally relies on barrel-like channels of a few nanometres width, but there is considerable scientific and technological interest for much wider structures of tunable shape. Yet, these nanopores do not exist in nature and are challenging to build using existing de novo routes for proteins10,15-17. Here, we show that rational design with DNA can drastically expand the structural and functional range of membrane nanopores. Our design strategy bundles DNA duplexes into pore subunits that modularly arrange to form tunable pore shapes and lumen widths of up to tens of nanometres. Functional units for recognition or signalling can be optionally attached. By dialling in essential parameters, we demonstrate the utility and potential of the custom-engineered nanopores by electrical direct single-molecule sensing of 10-nm-sized proteins using widely used research and hand-held analysis devices. The designer nanopores illustrate how DNA nanotechnology can deliver functional biomolecular structures to be used in synthetic biology, single-molecule enzymology and biophysical analysis, as well as portable diagnostics and environmental screening.
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Affiliation(s)
- Yongzheng Xing
- Department of Chemistry & Institute of Structural Molecular Biology, University College London, London, UK
| | - Adam Dorey
- Department of Chemistry & Institute of Structural Molecular Biology, University College London, London, UK
| | | | - Stefan Howorka
- Department of Chemistry & Institute of Structural Molecular Biology, University College London, London, UK.
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23
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Vikraman D, Satheesan R, Rajendran M, Kumar NA, Johnson JB, R SK, Mahendran KR. Selective Translocation of Cyclic Sugars through Dynamic Bacterial Transporter. ACS Sens 2022; 7:1766-1776. [PMID: 35671512 DOI: 10.1021/acssensors.2c00943] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The selective translocation of molecules through membrane pores is an integral process in cells. We present a bacterial sugar transporter, CymA of unusual structural conformation due to a dynamic N terminus segment in the pore, reducing its diameter. We quantified the translocation kinetics of various cyclic sugars of different charge, size, and symmetry across native and truncated CymA devoid of the N terminus using single-channel recordings. The chemically divergent cyclic hexasaccharides bind to the native and truncated pore with high affinity and translocate effectively. Specifically, these sugars bind and translocate rapidly through truncated CymA compared to native CymA. In contrast, larger cyclic heptasaccharides and octasaccharides do not translocate but bind to native and truncated CymA with distinct binding kinetics highlighting the importance of molecular charge, size and symmetry in translocation consistent with liposome assays. Based on the sugar-binding kinetics, we suggest that the N terminus most likely resides inside the native CymA barrel, regulating the transport rate of cyclic sugars. Finally, we present native CymA as a large nanopore sensor for the simultaneous single-molecule detection of various sugars at high resolution, establishing its functional versatility. This natural pore is expected to have several applications in nanobiotechnology and will help further our understanding of the fundamental mechanism of molecular transport.
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Affiliation(s)
- Devika Vikraman
- Membrane Biology Laboratory, Transdisciplinary Research Program, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram 695014, India.,Manipal Academy of Higher Education, Manipal, Karnataka 576104, India
| | - Remya Satheesan
- Membrane Biology Laboratory, Transdisciplinary Research Program, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram 695014, India.,Manipal Academy of Higher Education, Manipal, Karnataka 576104, India
| | - Mangaiyarkarasi Rajendran
- Membrane Biology Laboratory, Transdisciplinary Research Program, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram 695014, India
| | - Nisha Asok Kumar
- Manipal Academy of Higher Education, Manipal, Karnataka 576104, India.,Pathogen Biology, Virology, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala 695014, India
| | - John Bernet Johnson
- Pathogen Biology, Virology, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram, Kerala 695014, India
| | - Smrithi Krishnan R
- Membrane Biology Laboratory, Transdisciplinary Research Program, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram 695014, India.,Manipal Academy of Higher Education, Manipal, Karnataka 576104, India
| | - Kozhinjampara R Mahendran
- Membrane Biology Laboratory, Transdisciplinary Research Program, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram 695014, India
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24
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Prajapati JD, Pangeni S, Aksoyoglu MA, Winterhalter M, Kleinekathöfer U. Changes in Salt Concentration Modify the Translocation of Neutral Molecules through a ΔCymA Nanopore in a Non-monotonic Manner. ACS NANO 2022; 16:7701-7712. [PMID: 35435659 DOI: 10.1021/acsnano.1c11471] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The voltage-dependent transport through biological and artificial nanopores is being used in many applications such as DNA or protein sequencing and sensing. The primary approach to determine the transport has been to measure the temporal ion current fluctuations caused by solutes when applying external voltages. Crossing the nanoscale confinement in the presence of an applied electric field primarily relies on two factors, i.e., the electrophoretic drag and electroosmosis. The electroosmotic flow (EOF) is a voltage-dependent ion-associated flow of solvent molecules, i.e., usually water, and depends on many factors, such as pH, temperature, pore diameter, and also the concentration of ions. The exact interplay between these factors is so far poorly understood. In this joint experimental and computational study, we have investigated the dependence of the EOF on the concentration of the buffer salt by probing the transport of α-cyclodextrin molecules through the ΔCymA channel. For five different KCl concentrations in the range between 0.125 and 2 M, we performed applied-field molecular dynamics simulations and analyzed the ionic flow and the EOF across the ΔCymA pore. To our surprise, the concentration-dependent net ionic flux changes non-monotonically and nonlinearly and the EOF is seen to follow the same pattern. On the basis of these findings, we were able to correlate the concentration-dependent EOF with experimental kinetic constants for the translocation of α-cyclodextrin through the ΔCymA nanopore. Overall, the results further improve our understanding of the EOF-mediated transport through nanopores and show that the EOF needs to seriously be taken into consideration when analyzing the permeation of (neutral) substrates through nanopores.
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Affiliation(s)
| | - Sushil Pangeni
- Department of Life Sciences and Chemistry, Jacobs University Bremen, 28759 Bremen, Germany
| | | | - Mathias Winterhalter
- Department of Life Sciences and Chemistry, Jacobs University Bremen, 28759 Bremen, Germany
| | - Ulrich Kleinekathöfer
- Department of Physics and Earth Sciences, Jacobs University Bremen, 28759 Bremen, Germany
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Puthumadathil N, Krishnan R S, Nair GS, Mahendran KR. Assembly of alpha-helical transmembrane pores through an intermediate state. NANOSCALE 2022; 14:6507-6517. [PMID: 35420118 DOI: 10.1039/d2nr00556e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Pore-forming alpha-helical proteins are well known for their dynamic assembly mechanism and it has been challenging to delineate the pore-forming structures in membranes. Previously, attempts have been made to elucidate their assembly mechanism and there is a large gap due to complex pathways by which these membrane-active pores impart their effect. Here we demonstrate a multi-step structural assembly pathway of alpha-helical peptide pores formed by a 37 amino acid synthetic peptide, pPorU, based on the natural porin from Corynebacterium urealyticum using single-channel electrical recordings. More specifically, we report detectable intermediate states during the membrane insertion and pore formation of pPorU. The fully assembled pore exhibited unusually large stable conductance, voltage-dependent gating, and functional blockage by cyclic sugars generally applicable to a range of transmembrane pores. Furthermore, we used rationally designed mutants to understand the role of specific amino acids in the assembly of these peptide pores. Mutant peptides that differ from wild-type peptides produced noisy and unstable intermediate states and low conductance pores, demonstrating sequence specificity in the pore-formation process supported by molecular dynamics simulations. We suggest that our study contributes to understanding the mechanism of action of naturally occurring alpha-helical pore-forming proteins and should be of broad interest to build peptide-based nanopore sensors.
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Affiliation(s)
- Neethu Puthumadathil
- Membrane Biology Laboratory, Transdisciplinary Research Program, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram 695014, India.
- Manipal Academy of Higher Education, Manipal, Karnataka, 576104, India
| | - Smrithi Krishnan R
- Membrane Biology Laboratory, Transdisciplinary Research Program, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram 695014, India.
- Manipal Academy of Higher Education, Manipal, Karnataka, 576104, India
| | - Greeshma S Nair
- Membrane Biology Laboratory, Transdisciplinary Research Program, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram 695014, India.
| | - Kozhinjampara R Mahendran
- Membrane Biology Laboratory, Transdisciplinary Research Program, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram 695014, India.
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Abstract
Evolution has found countless ways to transport material across cells and cellular compartments separated by membranes. Protein assemblies are the cornerstone for the formation of channels and pores that enable this regulated passage of molecules in and out of cells, contributing to maintaining most of the fundamental processes that sustain living organisms. As in several other occasions, we have borrowed from the natural properties of these biological systems to push technology forward and have been able to hijack these nano-scale proteinaceous pores to learn about the physical and chemical features of molecules passing through them. Today, a large repertoire of biological pores is exploited as molecular sensors for characterizing biomolecules that are relevant for the advancement of life sciences and application to medicine. Although the technology has quickly matured to enable nucleic acid sensing with transformative implications for genomics, biological pores stand as some of the most promising candidates to drive the next developments in single-molecule proteomics.
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Affiliation(s)
- Simon Finn Mayer
- Institute of Bioengineering, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Chan Cao
- Institute of Bioengineering, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Matteo Dal Peraro
- Institute of Bioengineering, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
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Wan Y, Zong C, Li X, Wang A, Li Y, Yang T, Bao Q, Dubow M, Yang M, Rodrigo LA, Mao C. New Insights for Biosensing: Lessons from Microbial Defense Systems. Chem Rev 2022; 122:8126-8180. [PMID: 35234463 DOI: 10.1021/acs.chemrev.1c01063] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Microorganisms have gained defense systems during the lengthy process of evolution over millions of years. Such defense systems can protect them from being attacked by invading species (e.g., CRISPR-Cas for establishing adaptive immune systems and nanopore-forming toxins as virulence factors) or enable them to adapt to different conditions (e.g., gas vesicles for achieving buoyancy control). These microorganism defense systems (MDS) have inspired the development of biosensors that have received much attention in a wide range of fields including life science research, food safety, and medical diagnosis. This Review comprehensively analyzes biosensing platforms originating from MDS for sensing and imaging biological analytes. We first describe a basic overview of MDS and MDS-inspired biosensing platforms (e.g., CRISPR-Cas systems, nanopore-forming proteins, and gas vesicles), followed by a critical discussion of their functions and properties. We then discuss several transduction mechanisms (optical, acoustic, magnetic, and electrical) involved in MDS-inspired biosensing. We further detail the applications of the MDS-inspired biosensors to detect a variety of analytes (nucleic acids, peptides, proteins, pathogens, cells, small molecules, and metal ions). In the end, we propose the key challenges and future perspectives in seeking new and improved MDS tools that can potentially lead to breakthrough discoveries in developing a new generation of biosensors with a combination of low cost; high sensitivity, accuracy, and precision; and fast detection. Overall, this Review gives a historical review of MDS, elucidates the principles of emulating MDS to develop biosensors, and analyzes the recent advancements, current challenges, and future trends in this field. It provides a unique critical analysis of emulating MDS to develop robust biosensors and discusses the design of such biosensors using elements found in MDS, showing that emulating MDS is a promising approach to conceptually advancing the design of biosensors.
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Affiliation(s)
- Yi Wan
- State Key Laboratory of Marine Resource Utilization in the South China Sea, School of Pharmaceutical Sciences, Marine College, Hainan University, Haikou 570228, P. R. China
| | - Chengli Zong
- State Key Laboratory of Marine Resource Utilization in the South China Sea, School of Pharmaceutical Sciences, Marine College, Hainan University, Haikou 570228, P. R. China
| | - Xiangpeng Li
- Department of Bioengineering and Therapeutic Sciences, Schools of Medicine and Pharmacy, University of California, San Francisco, 1700 Fourth Street, Byers Hall 303C, San Francisco, California 94158, United States
| | - Aimin Wang
- State Key Laboratory of Marine Resource Utilization in the South China Sea, School of Pharmaceutical Sciences, Marine College, Hainan University, Haikou 570228, P. R. China
| | - Yan Li
- College of Animal Science, Zhejiang University, Hangzhou, Zhejiang 310058, P. R. China
| | - Tao Yang
- School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310058, P. R. China
| | - Qing Bao
- School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310058, P. R. China
| | - Michael Dubow
- Institute for Integrative Biology of the Cell (I2BC), UMR 9198 CNRS, CEA, Université Paris-Saclay, Campus C.N.R.S, Bâtiment 12, Avenue de la Terrasse, 91190 Gif-sur-Yvette, France
| | - Mingying Yang
- College of Animal Science, Zhejiang University, Hangzhou, Zhejiang 310058, P. R. China
| | - Ledesma-Amaro Rodrigo
- Imperial College Centre for Synthetic Biology, Department of Bioengineering, Imperial College London, London SW7 2AZ, United Kingdom
| | - Chuanbin Mao
- Department of Chemistry & Biochemistry, Stephenson Life Science Research Center, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States.,School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310058, P. R. China
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Hong J, Oh Y, Choi H, Kim J. Low-Area Four-Channel Controlled Dielectric Breakdown System Design for Point-of-Care Applications. SENSORS 2022; 22:s22051895. [PMID: 35271042 PMCID: PMC8914830 DOI: 10.3390/s22051895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 02/24/2022] [Accepted: 02/25/2022] [Indexed: 01/25/2023]
Abstract
In this study, we propose a low-area multi-channel controlled dielectric breakdown (CDB) system that simultaneously produces several nanopore sensors. Conventionally, solid-state nanopores are prepared by etching or drilling openings in a silicon nitride (SiNx) substrate, which is expensive and requires a long processing time. To address these challenges, a CDB technique was introduced and used to fabricate nanopore channels in SiNx membranes. However, the nanopore sensors produced by the CDB result in a severe pore-to-pore diameter variation as a result of different fabrication conditions and processing times. Accordingly, it is indispensable to simultaneously fabricate nanopore sensors in the same environment to reduce the deleterious effects of pore-to-pore variation. In this study, we propose a four-channel CDB system that comprises an amplifier that boosts the command voltage, a 1-to-4 multiplexer, a level shifter, a low-noise transimpedance amplifier and a data acquisition device. To prove our design concept, we used the CDB system to fabricate four nanopore sensors with diameters of <10 nm, and its in vitro performance was verified using λ-DNA samples.
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Affiliation(s)
- Jonggi Hong
- Department of Health Sciences & Technology, Gachon Advanced Institute for Health Sciences & Technology, Gachon University, Incheon 21999, Korea;
| | - Yeonji Oh
- Department of Medical Science, Korea University, Seoul 02841, Korea;
| | - Hojong Choi
- Department of Eletronic Engineering, Gachon University, Seongnam 13306, Korea
- Correspondence: (H.C.); (J.K.)
| | - Jungsuk Kim
- Department of Health Sciences & Technology, Gachon Advanced Institute for Health Sciences & Technology, Gachon University, Incheon 21999, Korea;
- Correspondence: (H.C.); (J.K.)
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El-Beyrouthy J, Makhoul-Mansour MM, Freeman EC. Studying the Mechanics of Membrane Permeabilization through Mechanoelectricity. ACS APPLIED MATERIALS & INTERFACES 2022; 14:6120-6130. [PMID: 35073482 DOI: 10.1021/acsami.1c19880] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
In this research, real-time monitoring of lipid membrane disruption is made possible by exploiting the dynamic properties of model lipid bilayers formed at oil-water interfaces. This involves tracking an electrical signal generated through rhythmic membrane perturbation translated into the adsorption and penetration of charged species within the membrane. Importantly, this allows for the detection of membrane surface interactions that occur prior to pore formation that may be otherwise undetected. The requisite dynamic membranes for this approach are made possible through the droplet interface bilayer (DIB) technique. Membranes are formed at the interface of lipid monolayer-coated aqueous droplets submerged in oil. We present how cyclically alternating the membrane area leads to the generation of mechanoelectric current. This current is negligible without a transmembrane voltage until a composition mismatch between the membrane monolayers is produced, such as a one-sided accumulation of disruptive agents. The generated mechanoelectric current is then eliminated when an applied electric field compensates for this asymmetry, enabling measurement of the transmembrane potential offset. Tracking the compensating voltage with respect to time then reveals the gradual accumulation of disruptive agents prior to membrane permeabilization. The innovation of this work is emphasized in its ability to continuously track membrane surface activity, highlighting the initial interaction steps of membrane disruption. In this paper, we begin by validating our proposed approach against measurements taken for fixed composition membranes using standard electrophysiological techniques. Next, we investigate surfactant adsorption, including hexadecyltrimethylammonium bromide (CTAB, cationic) and sodium decyl sulfate (SDS, anionic), demonstrating the ability to track adsorption prior to disruption. Finally, we investigate the penetration of lipid membranes by melittin, confirming that the peptide insertion and disruption mechanics are, in part, modulated by membrane composition.
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Affiliation(s)
- Joyce El-Beyrouthy
- Biomembranes Engineering Laboratory, School of Environment, Civil, Agriculture and Mechanical Engineering, The University of Georgia, Athens, Georgia 30602, United States
| | - Michelle M Makhoul-Mansour
- Biomembranes Engineering Laboratory, School of Environment, Civil, Agriculture and Mechanical Engineering, The University of Georgia, Athens, Georgia 30602, United States
| | - Eric C Freeman
- Biomembranes Engineering Laboratory, School of Environment, Civil, Agriculture and Mechanical Engineering, The University of Georgia, Athens, Georgia 30602, United States
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30
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Devarakonda S, Ganapathysubramanian B, Shrotriya P. Impedance-Based Nanoporous Anodized Alumina/ITO Platforms for Label-Free Biosensors. ACS APPLIED MATERIALS & INTERFACES 2022; 14:150-158. [PMID: 34937345 DOI: 10.1021/acsami.1c17243] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
We report an experimental and computational approach for the fabrication and characterization of a highly sensitive and responsive label-free biosensor that does not require the presence of redox couples in electrolytes for sensitive electrochemical detection. The sensor is based on an aptamer-functionalized transparent electrode composed of nanoporous anodized alumina (NAA) grown on indium tin oxide (ITO)-covered glass. Electrochemical impedance changes in a thrombin binding aptamer (TBA)-functionalized NAA/ITO/glass electrode due to specific binding of α-thrombin are monitored for protein detection. The aptamer-functionalized electrode enables sensitive and specific thrombin protein detection with a detection limit of ∼10 pM and a high signal-to-noise ratio. The transient impedance of the alumina film-covered surface is computed using a computational electrochemical impedance spectroscopy (EIS) approach and compared to experimental observations to identify the dominant mechanisms underlying the sensor response. The computational and experimental results indicate that the sensing response is due to the modified ionic transport under the combined influence of steric hindrance and surface charge modification due to ligand/receptor binding between α-thrombin and the aptamer-covered alumina film. These results suggest that alumina film-covered electrodes utilize both steric and charge modulation for sensing, leading to tremendous improvement in the sensitivity and signal-to-noise ratio. The film configuration is amenable for miniaturization and can be readily incorporated into existing portable sensing systems.
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Affiliation(s)
- Sivaranjani Devarakonda
- Department of Mechanical Engineering, Iowa State University, Ames, Iowa 50011, United States
| | | | - Pranav Shrotriya
- Department of Mechanical Engineering, Iowa State University, Ames, Iowa 50011, United States
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31
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Zhang L, Burns N, Jordan M, Jayasinghe L, Guo P. Macromolecule sensing and tumor biomarker detection by harnessing terminal size and hydrophobicity of viral DNA packaging motor channels into membranes and flow cells. Biomater Sci 2021; 10:167-177. [PMID: 34812812 DOI: 10.1039/d1bm01264a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Biological nanopores for single-pore sensing have the advantage of size homogeneity, structural reproducibility, and channel amenability. In order to translate this to clinical applications, the functional biological nanopore must be inserted into a stable system for high-throughput analysis. Here we report factors that control the rate of pore insertion into polymer membrane and analyte translocation through the channel of viral DNA packaging motors of Phi29, T3 and T7. The hydrophobicity of aminol or carboxyl terminals and their relation to the analyte translocation were investigated. It was found that both the size and the hydrophobicity of the pore terminus are critical factors for direct membrane insertion. An N-terminus or C-terminus hydrophobic mutation is crucial for governing insertion orientation and subsequent macromolecule translocation due to the one-way traffic property. The N- or C-modification led to two different modes of application. The C-terminal insertion permits translocation of analytes such as peptides to enter the channel through the N terminus, while N-terminus insertion prevents translocation but offers the measurement of gating as a sensing parameter, thus generating a tool for detection of markers. A urokinase-type Plasminogen Activator Receptor (uPAR) binding peptide was fused into the C-terminal of Phi29 nanopore to serve as a probe for uPAR protein detection. The uPAR has proven to be a predictive biomarker in several types of cancer, including breast cancer. With an N-terminal insertion, the binding of the uPAR antigen to individual peptide probe induced discretive steps of current reduction due to the induction of channel gating. The distinctive current signatures enabled us to distinguish uPAR positive and negative tumor cell lines. This finding provides a theoretical basis for a robust biological nanopore sensing system for high-throughput macromolecular sensing and tumor biomarker detection.
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Affiliation(s)
- Long Zhang
- Center for RNA Nanobiotechnology and Nanomedicine; College of Pharmacy; Dorothy M. Davis Heart and Lung Research Institute; James Comprehensive Cancer Center; College of Medicine; The Ohio State University, Columbus, OH 43210, USA.
| | - Nicolas Burns
- Center for RNA Nanobiotechnology and Nanomedicine; College of Pharmacy; Dorothy M. Davis Heart and Lung Research Institute; James Comprehensive Cancer Center; College of Medicine; The Ohio State University, Columbus, OH 43210, USA.
| | - Michael Jordan
- Oxford Nanopore Technologies Ltd, Gosling Building, Edmund Halley Road, Oxford Science Park, Oxford, OX4 4DQ, UK
| | - Lakmal Jayasinghe
- Oxford Nanopore Technologies Ltd, Gosling Building, Edmund Halley Road, Oxford Science Park, Oxford, OX4 4DQ, UK
| | - Peixuan Guo
- Center for RNA Nanobiotechnology and Nanomedicine; College of Pharmacy; Dorothy M. Davis Heart and Lung Research Institute; James Comprehensive Cancer Center; College of Medicine; The Ohio State University, Columbus, OH 43210, USA.
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32
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Akhtarian S, Miri S, Doostmohammadi A, Brar SK, Rezai P. Nanopore sensors for viral particle quantification: current progress and future prospects. Bioengineered 2021; 12:9189-9215. [PMID: 34709987 PMCID: PMC8810133 DOI: 10.1080/21655979.2021.1995991] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 10/16/2021] [Accepted: 10/16/2021] [Indexed: 12/24/2022] Open
Abstract
Rapid, inexpensive, and laboratory-free diagnostic of viral pathogens is highly critical in controlling viral pandemics. In recent years, nanopore-based sensors have been employed to detect, identify, and classify virus particles. By tracing ionic current containing target molecules across nano-scale pores, nanopore sensors can recognize the target molecules at the single-molecule level. In the case of viruses, they enable discrimination of individual viruses and obtaining important information on the physical and chemical properties of viral particles. Despite classical benchtop virus detection methods, such as amplification techniques (e.g., PCR) or immunological assays (e.g., ELISA), that are mainly laboratory-based, expensive and time-consuming, nanopore-based sensing methods can enable low-cost and real-time point-of-care (PoC) and point-of-need (PoN) monitoring of target viruses. This review discusses the limitations of classical virus detection methods in PoN virus monitoring and then provides a comprehensive overview of nanopore sensing technology and its emerging applications in quantifying virus particles and classifying virus sub-types. Afterward, it discusses the recent progress in the field of nanopore sensing, including integrating nanopore sensors with microfabrication technology, microfluidics and artificial intelligence, which have been demonstrated to be promising in developing the next generation of low-cost and portable biosensors for the sensitive recognition of viruses and emerging pathogens.
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Affiliation(s)
- Shiva Akhtarian
- Department of Mechanical Engineering, York University, Toronto, ON, Canada
| | - Saba Miri
- Department of Civil Engineering, York University, Toronto, ON, Canada
| | - Ali Doostmohammadi
- Department of Mechanical Engineering, York University, Toronto, ON, Canada
| | | | - Pouya Rezai
- Department of Mechanical Engineering, York University, Toronto, ON, Canada
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33
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Wu D, Zhu X, Ao J, Song E, Song Y. Delivery of Ultrasmall Nanoparticles to the Cytosolic Compartment of Pyroptotic J774A.1 Macrophages via GSDMD Nterm Membrane Pores. ACS APPLIED MATERIALS & INTERFACES 2021; 13:50823-50835. [PMID: 34689556 DOI: 10.1021/acsami.1c17382] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Endosome capture is a major physiological barrier to the successful delivery of nanomedicine. Here, we found a strategy to deliver ultrasmall nanoparticles (<10 nm) to the cytosolic compartment of pyroptotic cells with spontaneous endosomal escape. To mimic pathological pyroptotic cells, J774A.1 macrophages were stimulated with lipopolysaccharide (LPS) plus nigericin (Nig) or adenosine triphosphate (ATP) to form specific gasdermin D protein-driven membrane pores at an N-terminal domain (GSDMDNterm). Through GSDMDNterm membrane pores, both anionic and cationic nanoparticles (NPs) with diameters less than 10 nm were accessed into the cytosolic compartment of pyroptotic cells in an energy- and receptor-independent manner, while NPs larger than the size of GSDMDNterm membrane pores failed to enter pyroptotic cells. NPs pass through GSDMDNterm membrane pores via free diffusion and then access into the cytoplasm of pyroptotic cells in a microtubule-independent manner. Interestingly, we found that LPS-primed NPs may act as Trojan horse, deliver extracellular LPS into normal cells through endocytosis, and in turn induce GSDMDNterm membrane pores, which facilitate further internalization of NPs. This study presented a straightforward method of distinguishing normal and pyroptotic cells through GSDMD membrane pores, implicating their potential application in monitoring the delivery of desired nanomedicines in pyroptosis-related diseases and conditions.
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Affiliation(s)
- Di Wu
- Key Laboratory of Luminescence Analysis and Molecular Sensing, Ministry of Education, College of Pharmaceutical Sciences, Southwest University, 2 Tiansheng Road, Beibei District, Chongqing 400715, China
- School of Pharmacy, Zunyi Medical University, 6 West Xuefu Road, Xinpu District, Zunyi 563003, China
| | - Xiangyu Zhu
- Key Laboratory of Luminescence Analysis and Molecular Sensing, Ministry of Education, College of Pharmaceutical Sciences, Southwest University, 2 Tiansheng Road, Beibei District, Chongqing 400715, China
| | - Jian Ao
- College of Chemistry and Molecular Sciences, Wuhan University, 299 Bayi Road, Wuchang District, Wuhan 430072, China
| | - Erqun Song
- Key Laboratory of Luminescence Analysis and Molecular Sensing, Ministry of Education, College of Pharmaceutical Sciences, Southwest University, 2 Tiansheng Road, Beibei District, Chongqing 400715, China
| | - Yang Song
- Key Laboratory of Luminescence Analysis and Molecular Sensing, Ministry of Education, College of Pharmaceutical Sciences, Southwest University, 2 Tiansheng Road, Beibei District, Chongqing 400715, China
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, 18 Shuangqing Road, Haidian District, Beijing 100085, China
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Rahman M, Sampad MJN, Hawkins A, Schmidt H. Recent advances in integrated solid-state nanopore sensors. LAB ON A CHIP 2021; 21:3030-3052. [PMID: 34137407 PMCID: PMC8372664 DOI: 10.1039/d1lc00294e] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
The advent of single-molecule probing techniques has revolutionized the biomedical and life science fields and has spurred the development of a new class of labs-on-chip based on powerful biosensors. Nanopores represent one of the most recent and most promising single molecule sensing paradigms that is seeing increased chip-scale integration for improved convenience and performance. Due to their physical structure, nanopores are highly sensitive, require low sample volume, and offer label-free, amplification-free, high-throughput real-time detection and identification of biomolecules. Over the last 25 years, nanopores have been extensively employed to detect a variety of biomolecules with a growing range of applicatons ranging from nucleic acid sequencing to ultrasensitive diagnostics to single-molecule biophysics. Nanopores, in particular those in solid-state membranes, also have the potential for integration with other technologies such as optics, plasmonics, microfluidics, and optofluidics to perform more complex tasks for an ever-expanding demand. A number of breakthrough results using integrated nanopore platforms have already been reported, and more can be expected as nanopores remain the focus of innovative research and are finding their way into commercial instruments. This review provides an overview of different aspects and challenges of nanopore technology with a focus on chip-scale integration of solid-state nanopores for biosensing and bioanalytical applications.
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Affiliation(s)
- Mahmudur Rahman
- School of Engineering, University of California Santa Cruz, 1156 High Street, Santa Cruz, CA, 95064 USA. and Dhaka University of Engineering & Technology, Gazipur, Bangladesh
| | | | - Aaron Hawkins
- ECEn Department, Brigham Young University, 459 Clyde Building, Provo, UT, 84602 USA
| | - Holger Schmidt
- School of Engineering, University of California Santa Cruz, 1156 High Street, Santa Cruz, CA, 95064 USA.
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35
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Comparative study of anodization of small-scale and wafer-scale aluminum films on a silicon substrate and controlling pores shape for practical applications. J Electroanal Chem (Lausanne) 2021. [DOI: 10.1016/j.jelechem.2021.115367] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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36
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Fennouri A, List J, Ducrey J, Dupasquier J, Sukyte V, Mayer SF, Vargas RD, Pascual Fernandez L, Bertani F, Rodriguez Gonzalo S, Yang J, Mayer M. Tuning the Diameter, Stability, and Membrane Affinity of Peptide Pores by DNA-Programmed Self-Assembly. ACS NANO 2021; 15:11263-11275. [PMID: 34128638 DOI: 10.1021/acsnano.0c10311] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Protein pores recently enabled a breakthrough in bioanalytics by making it possible to sequence individual DNA and RNA strands during their translocation through the lumen of the pore. Despite this success and the overall promise of nanopore-based single-molecule analytics, protein pores have not yet reached their full potential for the analysis and characterization of globular biomolecules such as natively folded proteins. One reason is that the diameters of available protein pores are too small for accommodating the translocation of most folded globular proteins through their lumen. The work presented here provides a step toward overcoming this limitation by programmed self-assembly of α-helical pore-forming peptides with covalently attached single-stranded DNA (ssDNA). Specifically, hybridization of the peptide ceratotoxin A (CtxA) with N-terminally attached ssDNA to a complementary DNA template strand with 4, 8, or 12 hybridization sites made it possible to trigger the assembly of pores with various diameters ranging from approximately 0.5 to 4 nm. Hybridization of additional DNA strands to these assemblies achieved extended functionality in a modular fashion without the need for modifying the amino acid sequence of the peptides. For instance, functionalization of these semisynthetic biological nanopores with DNA-cholesterol anchors increased their affinity to lipid membranes compared to pores formed by native CtxA, while charged transmembrane segments prolonged their open-state lifetime. Assembly of these hybrid DNA-peptides by a template increased their cytotoxic activity and made it possible to kill cancer cells at 20-fold lower total peptide concentrations than nontemplated CtxA.
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Affiliation(s)
- Aziz Fennouri
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700 Fribourg, Switzerland
| | - Jonathan List
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700 Fribourg, Switzerland
| | - Julie Ducrey
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700 Fribourg, Switzerland
| | - Jessica Dupasquier
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700 Fribourg, Switzerland
| | - Viktorija Sukyte
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700 Fribourg, Switzerland
| | - Simon F Mayer
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700 Fribourg, Switzerland
| | - Reyner D Vargas
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700 Fribourg, Switzerland
| | - Laura Pascual Fernandez
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700 Fribourg, Switzerland
| | - Frederick Bertani
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700 Fribourg, Switzerland
| | - Sandra Rodriguez Gonzalo
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700 Fribourg, Switzerland
| | - Jerry Yang
- Department of Chemistry and Biochemistry, University of California, San Diego, California 92093, United States
| | - Michael Mayer
- Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700 Fribourg, Switzerland
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Fu S, Zhang T, Jiang H, Xu Y, Chen J, Zhang L, Su X. DNA nanotechnology enhanced single-molecule biosensing and imaging. Trends Analyt Chem 2021. [DOI: 10.1016/j.trac.2021.116267] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Novikova OD, Naberezhnykh GA, Sergeev AA. Nanostructured Biosensors Based on Components of Bacterial Membranes. Biophysics (Nagoya-shi) 2021. [DOI: 10.1134/s0006350921040187] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
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39
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Branching out the aerolysin, ETX/MTX-2 and Toxin_10 family of pore forming proteins. J Invertebr Pathol 2021; 186:107570. [PMID: 33775676 DOI: 10.1016/j.jip.2021.107570] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 12/15/2020] [Accepted: 03/09/2021] [Indexed: 01/28/2023]
Abstract
Organisms have evolved mechanisms in which cellular membranes can both be targeted and punctured thereby killing the targeted cell. One such mechanism involves the deployment of pore forming proteins (PFPs) which function by oligomerizing on cell membranes and inserting a physical pore spanning the membrane. This pore can lead to cell death by either causing osmotic flux or allowing the delivery of a secondary toxin. Pore forming proteins can be broadly classified into different families depending on the structure of the final pore; either α-PFPs using channels made from α -helices or β-PFPs using channels made from β-barrels. There are many different β-PFPs and an emerging superfamily is the aerolysin-ETX/MTX-2 superfamily. A comparison between the members of this superfamily reveals the pore forming domain is a common module yet the receptor binding region is highly variable. These structural and architectural variations lead to differences in the target recognition and determine the site of activity. Closer investigation of the topology of the family also suggests that the Toxin_10 family of PFPs could be considered as part of the aerolysin-ETX/MTX-2 superfamily. Comparatively, far less is known about how Toxin_10 proteins assemble into the final pore structure than aerolysin-ETX/MTX-2 proteins. This review aims to collate the pore forming protein members and bridge the structural similarities between the aerolysin-ETX/MTX-2 superfamily and the insecticidal Toxin_10 subfamily.
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Hub JS. Joint Reaction Coordinate for Computing the Free-Energy Landscape of Pore Nucleation and Pore Expansion in Lipid Membranes. J Chem Theory Comput 2021; 17:1229-1239. [PMID: 33427469 DOI: 10.1021/acs.jctc.0c01134] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Topological transitions of membranes, such as pore formation or membrane fusion, play key roles in biology, biotechnology, and in medical applications. Calculating the related free-energy landscapes has been complicated by the fact that such processes involve a sequence of transitions along highly distinct directions in conformational space, making it difficult to define good reaction coordinates (RCs) for the overall process. In this study, a new RC capable of driving both pore nucleation and pore expansion in lipid membranes is presented. The potential of mean force (PMF) along the RC computed with molecular dynamics simulations provides a comprehensive view on the free-energy landscape of pore formation, including a barrier for pore nucleation; the size, free energy, and metastability of the open pore; and the energetic cost for further pore expansion against the line tension of the pore rim. The RC is illustrated by quantifying the effects of (i) simulation system size and (ii) the addition of dimethyl sulfoxide on the free-energy landscape of pore formation. PMF calculations along the RC provide mechanistic and energetic understanding of pore formation, hence they will be useful to rationalize the effects of membrane-active peptides, electric fields, and membrane composition on transmembrane pores.
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Affiliation(s)
- Jochen S Hub
- Theoretical Physics and Center for Biophysics, Saarland University, Saarbrücken D-66123, Germany
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Dixit M, Lazaridis T. Free energy of hydrophilic and hydrophobic pores in lipid bilayers by free energy perturbation of a restraint. J Chem Phys 2021; 153:054101. [PMID: 32770888 DOI: 10.1063/5.0016682] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The free energy of pore formation in lipid bilayers has been previously calculated using a variety of reaction coordinates. Here, we use free energy perturbation of a cylindrical lipid exclusion restraint to compute the free energy profile as a function of pore radius in dimyristoylphosphatidylcholine (DMPC) and dioleoylphosphatidylcholine (DOPC) bilayers. Additionally restraining the headgroups to lie on the membrane surface allows us to also calculate the free energy profile of hydrophobic pores, i.e., cylindrical pores lined by acyl chains. For certain pore radii, the free energy of wetting of hydrophobic pores is calculated using the density bias method. It is found that wetting of hydrophobic pores becomes thermodynamically favorable at 5.0 Å for DMPC and 6.5 Å for DOPC, although significant barriers prevent spontaneous wetting of the latter on a nanosecond time scale. The free energy of transformation of hydrophilic pores to hydrophobic ones is also calculated using free energy perturbation of headgroup restraints along the bilayer normal. This quantity, along with wetting and pore growth free energies, provides complete free energy profiles as a function of radius. Pore line tension values for the hydrophilic pores obtained from the slope of the free energy profiles are 37.6 pN for DMPC and 53.7 pN for DOPC. The free energy profiles for the hydrophobic pores are analyzed in terms of elementary interfacial tensions. It is found that a positive three-phase line tension is required to explain the results. The estimated value for this three-phase line tension (51.2 pN) lies within the expected range.
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Affiliation(s)
- Mayank Dixit
- Department of Chemistry, City College of New York, 160 Convent Ave., New York, New York 10031, USA
| | - Themis Lazaridis
- Department of Chemistry, City College of New York, 160 Convent Ave., New York, New York 10031, USA
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42
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Catalytic Activity of Ni, Co, Mo Supported Anodic Aluminum Oxide Nanocomposites. BULLETIN OF CHEMICAL REACTION ENGINEERING & CATALYSIS 2020. [DOI: 10.9767/bcrec.15.3.8480.845-852] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Nanostructured catalysts based on porous aluminum oxide (PAO) and some 3d metals, such as: nickel, cobalt, and molybdenum, have been obtained by anodic oxidation and impregnation. The synthesis of porous aluminum oxide with a highly ordered pore structure with pore sizes of 50 nm and a thickness of 50 µm is carried out by the method of two-stage anodic oxidation. The catalysts are obtained by impregnation of 3d metals into nanosized pores of aluminum oxide. The obtained catalysts based on nickel and porous Al2O3 are studied by scanning electron microscopy (SEM-EDX). The results of SEM-EDX analysis shows that a spongy structure with filament sizes of 100 nanometers containing particles of 3d metals formed on the surface of the aluminum oxide matrix. The results are presented on the activity of nickel and heterogenic cobalt and molybdenum nanoparticles in the reaction of hydrogenation of hexene to hexane. The results show that the yield temperature of the hexane is decreased and the yield of hexane is observed at 200 °C with Ni/Al2O3 catalysts, and a similar yield of hexane mass is achieved at temperatures higher than 250 °C with Co-Mo/Al2O3 and traditional nickel catalysts on kieselguhr. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).
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43
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Multilayered film for the controlled formation of freestanding lipid bilayers. Colloids Surf B Biointerfaces 2020; 199:111552. [PMID: 33421926 DOI: 10.1016/j.colsurfb.2020.111552] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 12/05/2020] [Accepted: 12/19/2020] [Indexed: 11/23/2022]
Abstract
A freestanding lipid bilayer or black lipid membrane is a powerful tool for studying ion channels and for biophysical studies of other membrane proteins under controlled chemical and physical conditions. Even though the lipid bilayer has been considered an excellent sensing platform to detect diverse single molecules from nucleotides to cells, it is not yet widely used, mainly due to its low stability and the expertise needed for membrane formation. To ameliorate the issues of conventional membrane formation techniques, we report a novel layered film that consists of a nonporous layer sandwiched between two porous layers to facilitate bilayer formation. Moreover, the absorption of excess solvent present in the membrane precursor solution can be achieved by the film, enabling control over the membrane formation process. Through this layered design, we could obtain an ideal film that has a reduced and controlled membrane formation time (<30 min) and a sufficient bilayer lifetime (3 h) for ion channel studies and biosensing.
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Lanphere C, Offenbartl-Stiegert D, Dorey A, Pugh G, Georgiou E, Xing Y, Burns JR, Howorka S. Design, assembly, and characterization of membrane-spanning DNA nanopores. Nat Protoc 2020; 16:86-130. [PMID: 33349702 DOI: 10.1038/s41596-020-0331-7] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 04/06/2020] [Indexed: 01/08/2023]
Abstract
DNA nanopores are bio-inspired nanostructures that control molecular transport across lipid bilayer membranes. Researchers can readily engineer the structure and function of DNA nanopores to synergistically combine the strengths of DNA nanotechnology and nanopores. The pores can be harnessed in a wide range of areas, including biosensing, single-molecule chemistry, and single-molecule biophysics, as well as in cell biology and synthetic biology. Here, we provide a protocol for the rational design of nanobarrel-like DNA pores and larger DNA origami nanopores for targeted applications. We discuss strategies for the pores' chemical modification with lipid anchors to enable them to be inserted into membranes such as small unilamellar vesicles (SUVs) and planar lipid bilayers. The procedure covers the self-assembly of DNA nanopores via thermal annealing, their characterization using gel electrophoresis, purification, and direct visualization with transmission electron microscopy and atomic force microscopy. We also describe a gel assay to determine pore-membrane binding and discuss how to use single-channel current recordings and dye flux assays to confirm transport through the pores. We expect this protocol to take approximately 1 week to complete for DNA nanobarrel pores and 2-3 weeks for DNA origami pores.
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Affiliation(s)
- Conor Lanphere
- Department of Chemistry & Institute of Structural Molecular Biology, University College London, London, UK
| | - Daniel Offenbartl-Stiegert
- Department of Chemistry & Institute of Structural Molecular Biology, University College London, London, UK
| | - Adam Dorey
- Department of Chemistry & Institute of Structural Molecular Biology, University College London, London, UK
| | - Genevieve Pugh
- Department of Chemistry & Institute of Structural Molecular Biology, University College London, London, UK
| | - Elena Georgiou
- Department of Chemistry & Institute of Structural Molecular Biology, University College London, London, UK
| | - Yongzheng Xing
- Department of Chemistry & Institute of Structural Molecular Biology, University College London, London, UK
| | - Jonathan R Burns
- Department of Chemistry & Institute of Structural Molecular Biology, University College London, London, UK.
| | - Stefan Howorka
- Department of Chemistry & Institute of Structural Molecular Biology, University College London, London, UK.
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45
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Design and Assembly of Transmembrane Helix Barrel. J Membr Biol 2020; 253:491-497. [PMID: 33200236 DOI: 10.1007/s00232-020-00145-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 10/08/2020] [Indexed: 10/23/2022]
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46
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Prajapati JD, Kleinekathöfer U. Voltage-Dependent Transport of Neutral Solutes through Nanopores: A Molecular View. J Phys Chem B 2020; 124:10718-10731. [PMID: 33175522 DOI: 10.1021/acs.jpcb.0c08401] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The permeation of (neutral) molecules through nanopores in the presence of external voltages depends on several factors including pore electrostatics, electrophoretic force, and electro-osmotic drag. In earlier single-channel electrophysiology experiments, voltage-dependent asymmetric transport of neutral α-cyclodextrin (α-CD) molecules through the biological nanopore ΔCymA was observed. The voltage-dependent ion-associated flow of water, the so-called electro-osmotic flow, has been suggested to be the key factor behind the observed asymmetric behavior. The influence of pore electrostatics and electrophoretic force and their interplay with the electro-osmotic drag with varying buffers and voltages has not yet been analyzed at the molecular level. Hence, the detailed physical mechanism behind this intriguing permeation process is in part still unclear. In the present study, we have performed 36 μs all-atom free energy calculations by combining applied-field molecular dynamics simulations with metadynamics techniques. The influence of several ionic conditions as well as external voltages on the permeation of α-CD molecules across the ΔCymA pore has been investigated. To decipher the thermodynamic and kinetic details, the lowest energy paths and the permeation times for α-CD translocation have been estimated. In the presence of KCl or MgCl2 salts, the charge of the cations is found to control the direction and magnitude of the electro-osmotic flow, which in turn strongly affects α-CD permeation. Overall, the present findings significantly improve the fundamental understanding of the voltage-dependent transport of neutral solutes across nanopores.
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Affiliation(s)
| | - Ulrich Kleinekathöfer
- Department of Physics and Earth Sciences, Jacobs University Bremen, 28759 Bremen, Germany
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Lysenin Channels as Sensors for Ions and Molecules. SENSORS 2020; 20:s20216099. [PMID: 33120957 PMCID: PMC7663491 DOI: 10.3390/s20216099] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 10/19/2020] [Accepted: 10/23/2020] [Indexed: 12/18/2022]
Abstract
Lysenin is a pore-forming protein extracted from the earthworm Eisenia fetida, which inserts large conductance pores in artificial and natural lipid membranes containing sphingomyelin. Its cytolytic and hemolytic activity is rather indicative of a pore-forming toxin; however, lysenin channels present intricate regulatory features manifested as a reduction in conductance upon exposure to multivalent ions. Lysenin pores also present a large unobstructed channel, which enables the translocation of analytes, such as short DNA and peptide molecules, driven by electrochemical gradients. These important features of lysenin channels provide opportunities for using them as sensors for a large variety of applications. In this respect, this literature review is focused on investigations aimed at the potential use of lysenin channels as analytical tools. The described explorations include interactions with multivalent inorganic and organic cations, analyses on the reversibility of such interactions, insights into the regulation mechanisms of lysenin channels, interactions with purines, stochastic sensing of peptides and DNA molecules, and evidence of molecular translocation. Lysenin channels present themselves as versatile sensing platforms that exploit either intrinsic regulatory features or the changes in ionic currents elicited when molecules thread the conducting pathway, which may be further developed into analytical tools of high specificity and sensitivity or exploited for other scientific biotechnological applications.
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Karan S, Choudhury D, Dixit A. Enhanced expression of recombinant proteins in Escherichia coli by co-expression with Vibrio parahaemolyticus CsgG, a pore-forming protein of the curli biogenesis pathway. J Appl Microbiol 2020; 130:1611-1629. [PMID: 33025668 DOI: 10.1111/jam.14886] [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: 04/01/2020] [Revised: 09/11/2020] [Accepted: 09/30/2020] [Indexed: 11/28/2022]
Abstract
AIM To test whether engineered nanopores on the outer membrane (OM) of Escherichia coli can increase expression of heterologous proteins by making additional nutrients available to the host. METHODS AND RESULTS Outer membrane nanopores were generated by expressing recombinant Vibrio parahaemolyticus CsgG (rVpCsgG), which spontaneously assembles into a pore-forming channel on the OM, allowing spontaneous diffusion of small chemical entities from the exterior. Protein expression was probed using a reporter protein, sfGFP, expressed on a second compatible plasmid. OM pore formation was shown by acquired erythromycin sensitivity in cells transformed with rVpCsgG, influx of propidium iodide as well as by surface localization of recombinant CsgG by immunogold-labeled transmission electron microscopy. Expression of recombinant CsgG showed increased growth and also enhanced expression of sfGFP in minimal medium and is due to both enhanced transcription as well as translation. Similar enhancement of expression was also observed for a number of different proteins of different origin, sizes and nature. CONCLUSIONS Our findings clearly demonstrate that engineered nanopores on the OM of E. coli enhance expression of different heterologous proteins in minimal medium. SIGNIFICANCE AND IMPACT OF THE STUDY Vibrio parahaemolyticus CsgG β-nanopore mediated co-expression strategy to improve recombinant protein expression is fully compatible with other methods of protein expression enhancement, and therefore can be a useful tool in biotechnology particularly for whole-cell bio-transformations for production of secondary metabolite.
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Affiliation(s)
- S Karan
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
| | - D Choudhury
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
| | - A Dixit
- School of Biotechnology, Jawaharlal Nehru University, New Delhi, India
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Kwak DK, Kim JS, Lee MK, Ryu KS, Chi SW. Probing the Neuraminidase Activity of Influenza Virus Using a Cytolysin A Protein Nanopore. Anal Chem 2020; 92:14303-14308. [DOI: 10.1021/acs.analchem.0c03399] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Dong-Kyu Kwak
- Disease Target Structure Research Center, Division of Biomedical Research, KRIBB, Daejeon 34141, Republic of Korea
- Department of Proteome Structural Biology, KRIBB School of Bioscience, University of Science and Technology, Daejeon 34113, Republic of Korea
| | - Jin-Sik Kim
- Disease Target Structure Research Center, Division of Biomedical Research, KRIBB, Daejeon 34141, Republic of Korea
| | - Mi-Kyung Lee
- Disease Target Structure Research Center, Division of Biomedical Research, KRIBB, Daejeon 34141, Republic of Korea
| | - Kyoung-Seok Ryu
- Protein Structure Research Group, Korea Basic Science Institute, 162 Yeongudanji-ro, Ochang-eup, Cheongju-si, Chungcheongbuk-do 28119, Republic of Korea
| | - Seung-Wook Chi
- Disease Target Structure Research Center, Division of Biomedical Research, KRIBB, Daejeon 34141, Republic of Korea
- Department of Proteome Structural Biology, KRIBB School of Bioscience, University of Science and Technology, Daejeon 34113, Republic of Korea
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50
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Roozbahani GM, Chen X, Zhang Y, Wang L, Guan X. Nanopore detection of metal ions: Current status and future directions. SMALL METHODS 2020; 4:2000266. [PMID: 33365387 PMCID: PMC7751931 DOI: 10.1002/smtd.202000266] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Indexed: 05/27/2023]
Abstract
In this review, we highlight recent research efforts that aimed at developing nanopore sensors for detection of metal ions, which play a crucial role in environmental safety and human health. Protein pores use three stochastic sensing-based strategies for metal ion detection. The first strategy is to construct engineered nanopores with metal ion binding sites, so that the interaction between the target analytes and the nanopore can slow the movement of metal ions in the nano-channel. Second, large molecules such as nucleic acids and especially peptides could be utilized as external selective molecular probes to detect metal ions based on the conformational change of the ligand molecules induced by the metal ion-ligand chelation / coordination interaction. Third, enzymatic reactions can also be used as an alternative to the molecule probe strategy in the situation that a sensitive and selective probe molecule for the target analyte is difficult to obtain. On the other hand, by taking advantage of steady-state analysis, synthetic nanopores mainly use two strategies (modification and modification-free) to detect metals. Given the advantages of high sensitivity & selectivity, and label-free detection, nanopore-based metal ion sensors should find useful application in many fields, including environmental monitoring, medical diagnosis, and so on.
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Affiliation(s)
| | - Xiaohan Chen
- Department of Chemistry, Illinois Institute of Technology, Chicago, Illinois, 60616, USA
| | - Youwen Zhang
- Department of Chemistry, Illinois Institute of Technology, Chicago, Illinois, 60616, USA
| | - Liang Wang
- Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing 400714, China
- The University of Chinese Academy of Science, Beijing, 100049, China
| | - Xiyun Guan
- Department of Chemistry, Illinois Institute of Technology, Chicago, Illinois, 60616, USA
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