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Valenti D, Atlante A. Sound Matrix Shaping of Living Matter: From Macrosystems to Cell Microenvironment, Where Mitochondria Act as Energy Portals in Detecting and Processing Sound Vibrations. Int J Mol Sci 2024; 25:6841. [PMID: 38999952 PMCID: PMC11241420 DOI: 10.3390/ijms25136841] [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: 05/06/2024] [Revised: 06/18/2024] [Accepted: 06/19/2024] [Indexed: 07/14/2024] Open
Abstract
Vibration and sound are the shaping matrix of the entire universe. Everything in nature is shaped by energy vibrating and communicating through its own sound trail. Every cell within our body vibrates at defined frequencies, generating its peculiar "sound signature". Mitochondria are dynamic, energy-transforming, biosynthetic, and signaling organelles that actively transduce biological information. Novel research has shown that the mitochondrial function of mammalian cells can be modulated by various energetic stimuli, including sound vibrations. Regarding acoustic vibrations, definite types of music have been reported to produce beneficial impacts on human health. In very recent studies, the effects of different sound stimuli and musical styles on cellular function and mitochondrial activity were evaluated and compared in human cells cultured in vitro, investigating the underlying responsible molecular mechanisms. This narrative review will take a multilevel trip from macro to intracellular microenvironment, discussing the intimate vibrational sound activities shaping living matter, delving deeper into the molecular mechanisms underlying the sound modulation of biological systems, and mainly focusing our discussion on novel evidence showing the competence of mitochondria in acting as energy portals capable of sensing and transducing the subtle informational biofields of sound vibration.
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Affiliation(s)
- Daniela Valenti
- Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies (IBIOM), National Research Council (CNR), Via G. Amendola 122/O, 70126 Bari, Italy
| | - Anna Atlante
- Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies (IBIOM), National Research Council (CNR), Via G. Amendola 122/O, 70126 Bari, Italy
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2
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Hall D. Simulating biological surface dynamics in high-speed atomic force microscopy experiments. Biophys Rev 2023; 15:2069-2079. [PMID: 38192349 PMCID: PMC10771409 DOI: 10.1007/s12551-023-01169-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/21/2023] [Indexed: 01/10/2024] Open
Abstract
High-speed atomic force microscopy (HSAFM) is an important tool for studying the dynamic behavior of large biomolecular assemblies at surfaces. However, unlike light microscopy techniques, which visualize each point in the field of view at the same time, in HSAFM, the surface is literally imaged pixel-by-pixel with a variable extent of time separation existing between recordings made at one pixel and all others within the surface image. Such "temporal asynchronicity" in the recording of the spatial information can introduce distortions into the image when the surface components move at a rate comparable to that at which the surface is imaged. This Letter describes recently released software developments that are able to predict the likely form of these distortions and estimate confidence levels when assigning the identity of observed structures. These described approaches may facilitate both the design and optimization of future HSAFM experimental protocols. Further to this, they may assist in the interpretation of results from already published HSAFM studies.
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Affiliation(s)
- Damien Hall
- WPI Nano Life Science Institute, Kanazawa University, Kakumamachi, Kanazawa, Ishikawa 920-1164 Japan
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3
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Hall D. HSAFM-MIREBA - Methodology for Inferring REsolution in biological applications. Anal Biochem 2023; 681:115320. [PMID: 37717838 DOI: 10.1016/j.ab.2023.115320] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 08/22/2023] [Accepted: 09/10/2023] [Indexed: 09/19/2023]
Abstract
Due to a lack of requirement for any direct labelling of the target molecule, high speed atomic force microscopy (HS-AFM) is a potentially powerful procedure for the assessment of biological processes involving macromolecules. When the sample is static the AFM device can be purposefully setup to recover high-resolution information about the feature in question. However, when the feature to be studied moves an appreciable amount during the course of the measurement, the obtained image will be blurred. Encountering such blurred observations prompts the experimenter to sacrifice higher resolution images for higher scanning speeds by tuning available experimental parameters (such as the scanned image area, the image pixel size, the resonance frequency of the cantilever and/or the diameter of the AFM tip). The present work describes a software tool, HSAFM-MIREBA (High Speed Atomic Force Microscopy - Methodology for Inferring REsolution in Biological Applications) that allows for pre-experimental optimization of such parameters through iterative rounds of simulation of both the dynamic surface process and the HS-AFM measurement (based on the particular set of governing parameters). A representative set of five dynamic biological processes that describe a range of diffusive and directed motions (which can themselves be tuned by altering characteristic governing parameter sets) are provided.
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Affiliation(s)
- Damien Hall
- WPI Nano Life Science Institute. Kanazawa University, Kakumamachi, Kanazawa, Ishikawa, 920-1164, Japan.
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4
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Wijeratne SS, Subramanian R. Real-Time Visualization of Microtubule and Protofilament-Scale Dynamics in Multi-Microtubule Arrays by Atomic Force Microscopy. Curr Protoc 2023; 3:e779. [PMID: 37227098 PMCID: PMC10439732 DOI: 10.1002/cpz1.779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Microtubules, polymers of α, β-tubulin heterodimers, are organized into multi-microtubule arrays for diverse cellular functions. The dynamic properties of microtubule arrays govern their structural and functional properties. While numerous insights into the biophysical mechanisms underlying microtubule organization have been gleaned from in vitro reconstitution studies, the assays are largely restricted to visualization of single or pairs of microtubules. Thus, the dynamic processes underlying the remodeling of multi-microtubule arrays remain poorly understood. Recent work shows that Atomic Force Microscopy (AFM) enables the visualization of nanoscale dynamics within multi-microtubule 2D arrays. In this assay, electrostatic interactions permit the non-specific adsorption of microtubule arrays to mica. AFM imaging in tapping mode, a gentle method of imaging, allows the visualization of microtubules and protofilaments without sample damage. The height information captured by AFM imaging enables the tracking of structural changes in microtubules and protofilaments within multi-microtubule arrays over time. The experimental data from the method described here reveal previously unseen modes of nanoscale dynamics in microtubule bundles formed by the microtubule-crosslinking protein PRC1 in the presence of the depolymerase MCAK. The observations demonstrate the potential of AFM imaging in transforming our understanding of the fundamental cellular process by which multi-microtubule arrays are dynamically assembled and disassembled. © 2023 Wiley Periodicals LLC. Basic Protocol: Sample preparation and real-time visualization of microtubule arrays by atomic force microscopy Alternate Protocol: Protocol for coating surface with poly-L-lysine and immobilizing microtubules.
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Affiliation(s)
- Sithara S. Wijeratne
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114
- Department of Genetics, Harvard Medical School, Boston, MA 02115
| | - Radhika Subramanian
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114
- Department of Genetics, Harvard Medical School, Boston, MA 02115
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Atomic force microscopy reveals distinct protofilament-scale structural dynamics in depolymerizing microtubule arrays. Proc Natl Acad Sci U S A 2022; 119:2115708119. [PMID: 35101922 PMCID: PMC8812519 DOI: 10.1073/pnas.2115708119] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/09/2021] [Indexed: 12/01/2022] Open
Abstract
One cannot help but marvel at the precise organization of microtubule polymers in cellular structures such as the axoneme and the spindle. However, our understanding of the biochemical mechanisms that sculpt these arrays comes largely from in vitro experiments with a small number (one or two) of microtubules. This is somewhat akin to studying the architecture of multilane highways by studying one-lane streets. Here, we directly visualize depolymerizing microtubule arrays at individual microtubule and protofilament resolution using atomic force microscopy. Our results reveal differences in microtubule depolymerase activity and provide insights into how these differences in enzymatic activity on the nanometer scale can result in the differential remodeling of multimicrotubule arrays on the micron-length scale. The dynamic reorganization of microtubule-based cellular structures, such as the spindle and the axoneme, fundamentally depends on the dynamics of individual polymers within multimicrotubule arrays. A major class of enzymes implicated in both the complete demolition and fine size control of microtubule-based arrays are depolymerizing kinesins. How different depolymerases differently remodel microtubule arrays is poorly understood. A major technical challenge in addressing this question is that existing optical or electron-microscopy methods lack the spatial-temporal resolution to observe the dynamics of individual microtubules within larger arrays. Here, we use atomic force microscopy (AFM) to image depolymerizing arrays at single-microtubule and protofilament resolution. We discover previously unseen modes of microtubule array destabilization by conserved depolymerases. We find that the kinesin-13 MCAK mediates asynchronous protofilament depolymerization and lattice-defect propagation, whereas the kinesin-8 Kip3p promotes synchronous protofilament depolymerization. Unexpectedly, MCAK can depolymerize the highly stable axonemal doublets, but Kip3p cannot. We propose that distinct protofilament-level activities underlie the functional dichotomy of depolymerases, resulting in either large-scale destabilization or length regulation of microtubule arrays. Our work establishes AFM as a powerful strategy to visualize microtubule dynamics within arrays and reveals how nanometer-scale substrate specificity leads to differential remodeling of micron-scale cytoskeletal structures.
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Ganser C, Uchihashi T. Microtubule Preparation for Investigation with High-Speed Atomic Force Microscopy. Methods Mol Biol 2022; 2430:337-347. [PMID: 35476343 DOI: 10.1007/978-1-0716-1983-4_22] [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] [Indexed: 06/14/2023]
Abstract
High-speed atomic force microscopy (AFM) is a versatile method that can visualize proteins and protein systems on the nanometer scale and at a temporal resolution of 100 ms. The application to microtubules can not only reveal structural information with single-tubulin resolution but can also extract mechanical information and allows to study single motor proteins walking on microtubules, among others. This chapter provides a step-by-step guide from microtubule polymerization to successful observation with high-speed AFM.
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Affiliation(s)
- Christian Ganser
- Exploratory Research Center on Life and Living Systems, National Institutes of Natural Sciences, Okazaki, Aichi, Japan.
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Nasrin SR, Ganser C, Nishikawa S, Kabir AMR, Sada K, Yamashita T, Ikeguchi M, Uchihashi T, Hess H, Kakugo A. Deformation of microtubules regulates translocation dynamics of kinesin. SCIENCE ADVANCES 2021; 7:eabf2211. [PMID: 34644102 PMCID: PMC10763888 DOI: 10.1126/sciadv.abf2211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 08/20/2021] [Indexed: 06/13/2023]
Abstract
Microtubules, the most rigid components of the cytoskeleton, can be key transduction elements between external forces and the cellular environment. Mechanical forces induce microtubule deformation, which is presumed to be critical for the mechanoregulation of cellular events. However, concrete evidence is lacking. In this work, with high-speed atomic force microscopy, we unravel how microtubule deformation regulates the translocation of the microtubule-associated motor protein kinesin-1, responsible for intracellular transport. Our results show that the microtubule deformation by bending impedes the translocation dynamics of kinesins along them. Molecular dynamics simulation shows that the hindered translocation of kinesins can be attributed to an enhanced affinity of kinesins to the microtubule structural units in microtubules deformed by bending. This study advances our understanding of the role of cytoskeletal components in mechanotransduction.
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Affiliation(s)
| | - Christian Ganser
- Department of Creative Research, Exploratory Research Center on Life and Living Systems, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
| | - Seiji Nishikawa
- Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan
| | | | - Kazuki Sada
- Faculty of Science, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan
- Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan
| | - Takefumi Yamashita
- Laboratory for Systems Biology and Medicine, Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo 153-8904, Japan
| | - Mitsunori Ikeguchi
- Graduate School of Medical Life Science, Yokohama City University, Tsurumi-ku, Yokohama 230-0045, Japan
| | - Takayuki Uchihashi
- Department of Creative Research, Exploratory Research Center on Life and Living Systems, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
- Department of Physics, Nagoya University, Chikusa-ku, Nagoya 464-8602, Japan
| | - Henry Hess
- Department of Biomedical Engineering, Columbia University, New York, NY 10027, USA
| | - Akira Kakugo
- Faculty of Science, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan
- Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan
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8
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Hu X, Dinu CZ. A bio-pen for direct writing of single molecules on user-functionalized surfaces. NANOSCALE ADVANCES 2020; 2:156-165. [PMID: 36133986 PMCID: PMC9417116 DOI: 10.1039/c9na00379g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2019] [Accepted: 10/30/2019] [Indexed: 06/16/2023]
Abstract
Advancing ultrahigh resolution (below 10 nm) direct writing technologies could lead to impacts in areas as diverse as disease detection, genetic analysis and nanomanufacturing. Current methods based on electron-beams and photo- or dip-pen nanolithography are laborious and lack flexibility when aiming to create single molecule patterns for application specific integration. We hypothesize that a novel strategy could be developed to allow for writing of parallel and yet individually addressable patterns of single molecules on user-controlled surfaces. The strategy is based on using in vitro self-recognition of tubulin protein to assemble rigid protofilaments of microtubules, with one such microtubule to be subsequently used as a "bio-pen" capable of writing "inks" of single kinesin molecules in user-defined environments. Our results show that single kinesin inks could be written under the energy of adenosine triphosphate hydrolysis and observed by both atomic force and optical microscopy. Upon extending ink functionalities, the integration of soft and hard materials for nanostructure assembly and complex single molecule pattern formation is envisioned.
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Affiliation(s)
- Xiao Hu
- Department of Chemical and Biomedical Engineering, West Virginia University, Benjamin M. Statler College of Engineering and Mineral Resources PO Box 6102 Morgantown WV 26506 USA +1 304 293 4139 +1 304 293 9338
| | - Cerasela Zoica Dinu
- Department of Chemical and Biomedical Engineering, West Virginia University, Benjamin M. Statler College of Engineering and Mineral Resources PO Box 6102 Morgantown WV 26506 USA +1 304 293 4139 +1 304 293 9338
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9
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Chattrakun K, Hoogerheide DP, Mao C, Randall LL, King GM. Protein Translocation Activity in Surface-Supported Lipid Bilayers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:12246-12256. [PMID: 31448613 PMCID: PMC10906442 DOI: 10.1021/acs.langmuir.9b01928] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Surface-supported lipid bilayers are used widely throughout the nanoscience community as cellular membrane mimics. For example, they are frequently employed in single-molecule atomic force microscopy (AFM) studies to shed light on membrane protein conformational dynamics and folding. However, in AFM as well as in other surface-sensing techniques, the close proximity of the supporting surface raises questions about preservation of the biochemical activity. Employing the model translocase from the general secretory (Sec) system of Escherichia coli, here we quantify the activity via two biochemical assays in surface-supported bilayers. The first assesses ATP hydrolysis and the second assesses polypeptide translocation across the membrane via protection from added protease. Hydrolysis assays revealed distinct levels of activation ranging from medium (translocase-activated) to high (translocation-associated) that were similar to traditional solution experiments and further identified an adenosine triphosphatase population exhibiting characteristics of conformational hysteresis. Translocation assays revealed turn over numbers that were comparable to solution but with a 10-fold reduction in apparent rate constant. Despite differences in kinetics, the chemomechanical coupling (ATP hydrolyzed per residue translocated) only varied twofold on glass compared to solution. The activity changed with the topographic complexity of the underlying surface. Rough glass coverslips were favored over atomically flat mica, likely due to differences in frictional coupling between the translocating polypeptide and surface. Neutron reflectometry and AFM corroborated the biochemical measurements and provided structural characterization of the submembrane space and upper surface of the bilayer. Overall, the translocation activity was maintained for the surface-adsorbed Sec system, albeit with a slower rate-limiting step. More generally, polypeptide translocation activity measurements yield valuable quantitative metrics to assess the local environment about surface-supported lipid bilayers.
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Affiliation(s)
- Kanokporn Chattrakun
- Department of Physics and Astronomy, University of Missouri-Columbia, Columbia, Missouri 65211, United States
| | - David P. Hoogerheide
- Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Chunfeng Mao
- Department of Biochemistry, University of Missouri-Columbia, Columbia, Missouri 65211, United States
| | - Linda L. Randall
- Department of Biochemistry, University of Missouri-Columbia, Columbia, Missouri 65211, United States
| | - Gavin M. King
- Department of Physics and Astronomy, University of Missouri-Columbia, Columbia, Missouri 65211, United States
- Department of Biochemistry, University of Missouri-Columbia, Columbia, Missouri 65211, United States
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10
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Abraham Z, Hawley E, Hayosh D, Webster-Wood VA, Akkus O. Kinesin and Dynein Mechanics: Measurement Methods and Research Applications. J Biomech Eng 2019; 140:2654261. [PMID: 28901373 DOI: 10.1115/1.4037886] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2017] [Indexed: 11/08/2022]
Abstract
Motor proteins play critical roles in the normal function of cells and proper development of organisms. Among motor proteins, failings in the normal function of two types of proteins, kinesin and dynein, have been shown to lead many pathologies, including neurodegenerative diseases and cancers. As such, it is critical to researchers to understand the underlying mechanics and behaviors of these proteins, not only to shed light on how failures may lead to disease, but also to guide research toward novel treatment and nano-engineering solutions. To this end, many experimental techniques have been developed to measure the force and motility capabilities of these proteins. This review will (a) discuss such techniques, specifically microscopy, atomic force microscopy (AFM), optical trapping, and magnetic tweezers, and (b) the resulting nanomechanical properties of motor protein functions such as stalling force, velocity, and dependence on adenosine triphosophate (ATP) concentrations will be comparatively discussed. Additionally, this review will highlight the clinical importance of these proteins. Furthermore, as the understanding of the structure and function of motor proteins improves, novel applications are emerging in the field. Specifically, researchers have begun to modify the structure of existing proteins, thereby engineering novel elements to alter and improve native motor protein function, or even allow the motor proteins to perform entirely new tasks as parts of nanomachines. Kinesin and dynein are vital elements for the proper function of cells. While many exciting experiments have shed light on their function, mechanics, and applications, additional research is needed to completely understand their behavior.
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Affiliation(s)
- Zachary Abraham
- Department of Mechanical and Aerospace Engineering, Case Western Reserve University, Cleveland, OH 44106
| | - Emma Hawley
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106
| | - Daniel Hayosh
- Department of Mechanical and Aerospace Engineering, Case Western Reserve University, Cleveland, OH 44106
| | - Victoria A Webster-Wood
- Mem. ASME Department of Mechanical and Aerospace Engineering, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106 e-mail:
| | - Ozan Akkus
- Mem. ASME Department of Mechanical and Aerospace Engineering, Case Western Reserve University, Cleveland, OH 44106
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11
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Facchin F, Canaider S, Tassinari R, Zannini C, Bianconi E, Taglioli V, Olivi E, Cavallini C, Tausel M, Ventura C. Physical energies to the rescue of damaged tissues. World J Stem Cells 2019; 11:297-321. [PMID: 31293714 PMCID: PMC6600852 DOI: 10.4252/wjsc.v11.i6.297] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 04/24/2019] [Accepted: 05/29/2019] [Indexed: 02/06/2023] Open
Abstract
Rhythmic oscillatory patterns sustain cellular dynamics, driving the concerted action of regulatory molecules, microtubules, and molecular motors. We describe cellular microtubules as oscillators capable of synchronization and swarming, generating mechanical and electric patterns that impact biomolecular recognition. We consider the biological relevance of seeing the inside of cells populated by a network of molecules that behave as bioelectronic circuits and chromophores. We discuss the novel perspectives disclosed by mechanobiology, bioelectromagnetism, and photobiomodulation, both in term of fundamental basic science and in light of the biomedical implication of using physical energies to govern (stem) cell fate. We focus on the feasibility of exploiting atomic force microscopy and hyperspectral imaging to detect signatures of nanomotions and electromagnetic radiation (light), respectively, generated by the stem cells across the specification of their multilineage repertoire. The chance is reported of using these signatures and the diffusive features of physical waves to direct specifically the differentiation program of stem cells in situ, where they already are resident in all the tissues of the human body. We discuss how this strategy may pave the way to a regenerative and precision medicine without the needs for (stem) cell or tissue transplantation. We describe a novel paradigm based upon boosting our inherent ability for self-healing.
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Affiliation(s)
- Federica Facchin
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), School of Medicine, University of Bologna, Bologna 40100, Italy
- National Laboratory of Molecular Biology and Stem Cell Engineering, National Institute of Biostructures and Biosystems, CNR, Bologna 40100, Italy
| | - Silvia Canaider
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), School of Medicine, University of Bologna, Bologna 40100, Italy
- National Laboratory of Molecular Biology and Stem Cell Engineering, National Institute of Biostructures and Biosystems, CNR, Bologna 40100, Italy
| | - Riccardo Tassinari
- National Laboratory of Molecular Biology and Stem Cell Engineering, National Institute of Biostructures and Biosystems, CNR, Bologna 40100, Italy
| | - Chiara Zannini
- National Laboratory of Molecular Biology and Stem Cell Engineering, National Institute of Biostructures and Biosystems, CNR, Bologna 40100, Italy
| | - Eva Bianconi
- National Laboratory of Molecular Biology and Stem Cell Engineering, National Institute of Biostructures and Biosystems, CNR, Bologna 40100, Italy
| | - Valentina Taglioli
- National Laboratory of Molecular Biology and Stem Cell Engineering, National Institute of Biostructures and Biosystems, CNR, Bologna 40100, Italy
| | - Elena Olivi
- National Laboratory of Molecular Biology and Stem Cell Engineering, National Institute of Biostructures and Biosystems, CNR, Bologna 40100, Italy
| | - Claudia Cavallini
- National Laboratory of Molecular Biology and Stem Cell Engineering, National Institute of Biostructures and Biosystems, CNR, Bologna 40100, Italy
| | | | - Carlo Ventura
- Department of Experimental, Diagnostic and Specialty Medicine (DIMES), School of Medicine, University of Bologna, Bologna 40100, Italy
- National Laboratory of Molecular Biology and Stem Cell Engineering, National Institute of Biostructures and Biosystems, CNR, Bologna 40100, Italy
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12
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Hu X, Guiseppi-Elie A, Dinu CZ. Biomolecular interfaces based on self-assembly and self-recognition form biosensors capable of recording molecular binding and release. NANOSCALE 2019; 11:4987-4998. [PMID: 30839012 DOI: 10.1039/c8nr10090j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
This research proposed to create the next generation of versatile electrochemical-based biosensors capable of monitoring target capture and release as dictated by molecular binding or unbinding. The biosensor integrates cellular machines (i.e., microtubules, structural elements of cells and kinesin molecular motors involved in cellular transport) as functional units; its assembly is based on molecular self-assembly and self-recognition. Our results demonstrate that the designed biosensor was capable of allowing detection of binding and unbinding events based on redox reactions at user-controlled electrode interfaces. The analysis also showed that the sensitivity of the designed biosensor or its ability to record such events could be user-controlled at any given time by adjusting the energy source that "fuels" the system.
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Affiliation(s)
- Xiao Hu
- Department of Chemical and Biomedical Engineering, West Virginia University, WV, USA.
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13
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Hu X, Fagone P, Dong C, Su R, Xu Q, Dinu CZ. Biological Self-Assembly and Recognition Used to Synthesize and Surface Guide Next Generation of Hybrid Materials. ACS APPLIED MATERIALS & INTERFACES 2018; 10:28372-28381. [PMID: 29939708 DOI: 10.1021/acsami.8b09421] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Free-standing, high aspect ratio sulfur-doped carbon nanodot-based hybrid nanowires with a microtubular aspect were synthesized using self-recognition and self-assembly processes of tubulin, a biological molecule precursor of the cytoskeletal microtubule. Physicochemical characterizations (e.g., morphology, diameter, spectral characteristics, etc.) of such user-synthesized hybrid bionanowires were performed using classical atomic and spectroscopic techniques, whereas bioactivity and functionality testing was demonstrated by mimicking cellular transport based on kinesin, a motor protein capable to recognize, and move on the microtubules. Our results indicate that user-synthesized hybrid nanowires could be manipulated in vitro under constant chemical energy of adenosine triphosphate and have the potential to be implemented in the next generation of synthetic applications from drug delivery to diagnosis systems, and photocatalytic to optical devices.
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Affiliation(s)
| | | | | | - Rigu Su
- State Key Laboratory of Heavy Oil Processing , China University of Petroleum (Beijing) , Beijing 102249 , China
| | - Quan Xu
- State Key Laboratory of Heavy Oil Processing , China University of Petroleum (Beijing) , Beijing 102249 , China
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14
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Song W, Zhu J, Kong W, Möhwald H, Li J. Different Microtubule Structures Assembled by Kinesin Motors. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:9768-9773. [PMID: 30021432 DOI: 10.1021/acs.langmuir.8b00662] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The microtubule-kinesin system is used to form microtubule-based structures via microtubule gliding motility. On the kinesin-coated surface, the microtubules can be easily assembled into stable micro- and nanostructures like circles and microtubule bundles using the streptavidin-biotin system. Furthermore, these microtubules structures can still retain performance with kinesin motor movement in spite of different velocities. Collisions bear responsibility for the majority of events leading to circle formation. By taking advantage of biological substances, some micro- or nanostructures, which are difficult to fabricate by artificial processes, can be easily obtained.
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Affiliation(s)
- Weixing Song
- Department of Chemistry , Capital Normal University , Beijing 100048 , P.R. China
| | - Jianxiong Zhu
- School of Mechanical Engineering , Korea Advanced Institute of Science and Technology (KAIST) , 291 Daehak-ro, Yuseong-gu , Daejeon 34141 , Republic of Korea
| | - Weimin Kong
- Department of Chemistry , Capital Normal University , Beijing 100048 , P.R. China
| | - Helmuth Möhwald
- Max Planck Institute of Colloids and Interfaces , Am Mühlenberg 1 , Golm, Potsdam D-14476 , Germany
| | - Junbai Li
- Beijing National Laboratory for Molecular Sciences (BNLMS), International Joint Lab, Institute of Chemistry, Chinese Academy of Science , Beijing 100080 , China
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15
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Smith JA, Slusher BS, Wozniak KM, Farah MH, Smiyun G, Wilson L, Feinstein S, Jordan MA. Structural Basis for Induction of Peripheral Neuropathy by Microtubule-Targeting Cancer Drugs. Cancer Res 2016; 76:5115-23. [DOI: 10.1158/0008-5472.can-15-3116] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 06/13/2016] [Indexed: 11/16/2022]
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16
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Ventura C, Tavazzi L. Biophysical signalling from and to the (stem) cells: a novel path to regenerative medicine. Eur J Heart Fail 2016; 18:1405-1407. [PMID: 27407069 DOI: 10.1002/ejhf.607] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 06/07/2016] [Indexed: 01/17/2023] Open
Affiliation(s)
- Carlo Ventura
- Maria Cecilia Hospital, Gruppo Villa Maria (GVM) Care & Research and Ettore Sansavini Health Science Foundation, Cotignola and Lugo, Ravenna, Italy.,Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, Italy
| | - Luigi Tavazzi
- Maria Cecilia Hospital, Gruppo Villa Maria (GVM) Care & Research and Ettore Sansavini Health Science Foundation, Cotignola and Lugo, Ravenna, Italy
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17
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Usukura E, Narita A, Yagi A, Ito S, Usukura J. An Unroofing Method to Observe the Cytoskeleton Directly at Molecular Resolution Using Atomic Force Microscopy. Sci Rep 2016; 6:27472. [PMID: 27273367 PMCID: PMC4895337 DOI: 10.1038/srep27472] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Accepted: 05/19/2016] [Indexed: 11/09/2022] Open
Abstract
An improved unroofing method enabled the cantilever of an atomic force microscope (AFM) to reach directly into a cell to visualize the intracellular cytoskeletal actin filaments, microtubules, clathrin coats, and caveolae in phosphate-buffered saline (PBS) at a higher resolution than conventional electron microscopy. All of the actin filaments clearly exhibited a short periodicity of approximately 5-6 nm, which was derived from globular actins linked to each other to form filaments, as well as a long helical periodicity. The polarity of the actin filaments appeared to be determined by the shape of the periodic striations. Microtubules were identified based on their thickness. Clathrin coats and caveolae were observed on the cytoplasmic surface of cell membranes. The area containing clathrin molecules and their terminal domains was directly visualized. Characteristic ridge structures located at the surface of the caveolae were observed at high resolution, similar to those observed with electron microscopy (EM). Overall, unroofing allowed intracellular AFM imaging in a liquid environment with a level of quality equivalent or superior to that of EM. Thus, AFMs are anticipated to provide cutting-edge findings in cell biology and histology.
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Affiliation(s)
- Eiji Usukura
- Structural Biology Research Centre, Graduate School of Science, Nagoya University, Nagoya, 464-8603 Japan
| | - Akihiro Narita
- Structural Biology Research Centre, Graduate School of Science, Nagoya University, Nagoya, 464-8603 Japan
| | - Akira Yagi
- Olympus Corporation, Hachioji, Tokyo, 192-8512 Japan
| | - Shuichi Ito
- Olympus Corporation, Hachioji, Tokyo, 192-8512 Japan
| | - Jiro Usukura
- Structural Biology Research Centre, Graduate School of Science, Nagoya University, Nagoya, 464-8603 Japan
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18
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Wilts BD, Schaap IAT, Schmidt CF. Swelling and softening of the cowpea chlorotic mottle virus in response to pH shifts. Biophys J 2016; 108:2541-2549. [PMID: 25992732 DOI: 10.1016/j.bpj.2015.04.019] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 04/03/2015] [Accepted: 04/15/2015] [Indexed: 11/17/2022] Open
Abstract
Cowpea chlorotic mottle virus (CCMV) forms highly elastic icosahedral protein capsids that undergo a characteristic swelling transition when the pH is raised from 5 to 7. Here, we performed nano-indentation experiments using an atomic force microscope to track capsid swelling and measure the shells' Young's modulus at the same time. When we chelated Ca(2+) ions and raised the pH, we observed a gradual swelling of the RNA-filled capsids accompanied by a softening of the shell. Control experiments with empty wild-type virus and a salt-stable mutant revealed that the softening was not strictly coupled to the swelling of the protein shells. Our data suggest that a pH increase and Ca(2+) chelation lead primarily to a loosening of contacts within the protein shell, resulting in a softening of the capsid. This appears to render the shell metastable and make swelling possible when repulsive forces among the capsid proteins become large enough, which is known to be followed by capsid disassembly at even higher pH. Thus, softening and swelling are likely to play a role during inoculation.
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Affiliation(s)
- Bodo D Wilts
- Drittes Physikalisches Institut, Fakultät für Physik, Georg-August Universität, Göttingen, Germany
| | - Iwan A T Schaap
- Drittes Physikalisches Institut, Fakultät für Physik, Georg-August Universität, Göttingen, Germany; Center for Nanoscale Microscopy and Molecular Physiology of the Brain, Göttingen, Germany
| | - Christoph F Schmidt
- Drittes Physikalisches Institut, Fakultät für Physik, Georg-August Universität, Göttingen, Germany.
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19
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Šarlah A, Vilfan A. The winch model can explain both coordinated and uncoordinated stepping of cytoplasmic dynein. Biophys J 2015; 107:662-671. [PMID: 25099805 DOI: 10.1016/j.bpj.2014.06.022] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Revised: 05/16/2014] [Accepted: 06/16/2014] [Indexed: 12/23/2022] Open
Abstract
Cytoplasmic dynein moves processively along microtubules, but the mechanism of how its heads use the energy from ATP hydrolysis, coupled to a linker swing, to achieve directed motion, is still unclear. In this article, we present a theoretical model based on the winch mechanism in which the principal direction of the linker stroke is toward the microtubule-binding domain. When mechanically coupling two identical heads (each with postulated elastic properties and a minimal ATPase cycle), the model reproduces stepping with 8-nm steps (even though the motor itself is much larger), interhead coordination, and processivity, as reported for mammalian dyneins. Furthermore, when we loosen the elastic connection between the heads, the model still shows processive directional stepping, but it becomes uncoordinated and the stepping pattern shows a greater variability, which reproduces the properties of yeast dyneins. Their slower chemical kinetics allows processive motility and a high stall force without the need for coordination.
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Affiliation(s)
- Andreja Šarlah
- Faculty of Mathematics and Physics, University of Ljubljana, Ljubljana, Slovenia
| | - Andrej Vilfan
- Faculty of Mathematics and Physics, University of Ljubljana, Ljubljana, Slovenia; J. Stefan Institute, Ljubljana, Slovenia.
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20
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Davies T, Kodera N, Kaminski Schierle GS, Rees E, Erdelyi M, Kaminski CF, Ando T, Mishima M. CYK4 promotes antiparallel microtubule bundling by optimizing MKLP1 neck conformation. PLoS Biol 2015; 13:e1002121. [PMID: 25875822 PMCID: PMC4395295 DOI: 10.1371/journal.pbio.1002121] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Accepted: 03/05/2015] [Indexed: 11/19/2022] Open
Abstract
Centralspindlin, a constitutive 2:2 heterotetramer of MKLP1 (a kinesin-6) and the non-motor subunit CYK4, plays important roles in cytokinesis. It is crucial for the formation of central spindle microtubule bundle structure. Its accumulation at the central antiparallel overlap zone is key for recruitment and regulation of downstream cytokinesis factors and for stable anchoring of the plasma membrane at the midbody. Both MKLP1 and CYK4 are required for efficient microtubule bundling. However, the mechanism by which CYK4 contributes to this is unclear. Here we performed structural and functional analyses of centralspindlin using high-speed atomic force microscopy, Fӧrster resonance energy transfer analysis, and in vitro reconstitution. Our data reveal that CYK4 binds to a globular mass in the atypically long MKLP1 neck domain between the catalytic core and the coiled coil and thereby reconfigures the two motor domains in the MKLP1 dimer to be suitable for antiparallel microtubule bundling. Our work provides insights into the microtubule bundling during cytokinesis and into the working mechanisms of the kinesins with non-canonical neck structures. Cell division depends on the antiparallel bundling of microtubules by a motor complex called centralpindlin. This study reveals how the centralspindlin non-motor subunit CYK4 reconfigures the motor domains of the kinesin subunit MKLP1 to help it carry out this role. Cell division requires coordination of many different cellular components. Cytokinesis is the process by which the cytoplasm divides between the two forming daughter cells. During cytokinesis, centralspindlin is truly central, as it organizes microtubule bundle structures, recruits other factors to the site of division, and anchors the plasma membrane at the inter-cellular bridge while the two daughter cells are waiting for the final separation. Centralspindlin is a heterotetramer composed of two molecules of a kinesin-6 motor subunit, MKLP1, and two molecules of the second subunit, CYK4. For efficient microtubule bundling, both the microtubule motor subunit MKLP1 and the non-motor CYK4 subunit are required. However, it has remained unclear how CYK4 contributes to this activity. Here, we took a combinatorial approach to investigate this process, using in vitro reconstitution and structural analyses by atomic force microscopy and Förster resonance energy transfer. We revealed that the CYK4 dimer binds to a hitherto unknown globular domain at the neck of the MKLP1 dimer and optimizes the configuration of two motor domains, making them suitable for antiparallel microtubule bundling. This provides novel insight into how other kinesin superfamily molecules with non-canonical neck structures may work.
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Affiliation(s)
- Tim Davies
- Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge, United Kingdom
| | - Noriyuki Kodera
- Department of Physics and Bio-AFM Frontier Research Center, Kanazawa University, Kanazawa, Japan
| | - Gabriele S. Kaminski Schierle
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Pembroke Street, Cambridge, United Kingdom
| | - Eric Rees
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Pembroke Street, Cambridge, United Kingdom
| | - Miklos Erdelyi
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Pembroke Street, Cambridge, United Kingdom
| | - Clemens F. Kaminski
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Pembroke Street, Cambridge, United Kingdom
| | - Toshio Ando
- Department of Physics and Bio-AFM Frontier Research Center, Kanazawa University, Kanazawa, Japan
| | - Masanori Mishima
- Biomedical Cell Biology, Warwick Medical School, University of Warwick, Gibbet Hill Road, Coventry, United Kingdom
- * E-mail:
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21
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Dannhauser PN, Platen M, Böning H, Ungewickell H, Schaap IA, Ungewickell EJ. Effect of Clathrin Light Chains on the Stiffness of Clathrin Lattices and Membrane Budding. Traffic 2015; 16:519-33. [DOI: 10.1111/tra.12263] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Revised: 01/09/2015] [Accepted: 01/12/2015] [Indexed: 01/19/2023]
Affiliation(s)
- Philip N. Dannhauser
- Institute of Cell Biology, Centre of Anatomy; Hannover Medical School; Carl-Neuberg Street 1 D-30625 Hannover Germany
| | - Mitja Platen
- IIIrd Institute of Physics; Georg August University; Göttingen Germany
| | - Heike Böning
- Institute of Cell Biology, Centre of Anatomy; Hannover Medical School; Carl-Neuberg Street 1 D-30625 Hannover Germany
| | - Huberta Ungewickell
- Institute of Cell Biology, Centre of Anatomy; Hannover Medical School; Carl-Neuberg Street 1 D-30625 Hannover Germany
| | - Iwan A.T. Schaap
- IIIrd Institute of Physics; Georg August University; Göttingen Germany
- Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB); Göttingen Germany
| | - Ernst J. Ungewickell
- Institute of Cell Biology, Centre of Anatomy; Hannover Medical School; Carl-Neuberg Street 1 D-30625 Hannover Germany
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22
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Cochran JC. Kinesin Motor Enzymology: Chemistry, Structure, and Physics of Nanoscale Molecular Machines. Biophys Rev 2015; 7:269-299. [PMID: 28510227 DOI: 10.1007/s12551-014-0150-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Accepted: 11/16/2014] [Indexed: 11/25/2022] Open
Abstract
Molecular motors are enzymes that convert chemical potential energy into controlled kinetic energy for mechanical work inside cells. Understanding the biophysics of these motors is essential for appreciating life as well as apprehending diseases that arise from motor malfunction. This review focuses on kinesin motor enzymology with special emphasis on the literature that reports the chemistry, structure and physics of several different kinesin superfamily members.
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Affiliation(s)
- J C Cochran
- Department of Molecular & Cellular Biochemistry, Indiana University, Simon Hall Room 405C, 212 S. Hawthorne Dr., Bloomington, IN, 47405, USA.
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23
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Elevated copper ion levels as potential cause of impaired kinesin-dependent transport processes. Arch Toxicol 2014; 89:565-72. [DOI: 10.1007/s00204-014-1272-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Accepted: 05/13/2014] [Indexed: 01/01/2023]
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24
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Kinesin-dependent motility generation as target mechanism of cadmium intoxication. Toxicol Lett 2014; 224:356-61. [DOI: 10.1016/j.toxlet.2013.11.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Revised: 11/01/2013] [Accepted: 11/04/2013] [Indexed: 02/01/2023]
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25
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Kull FJ, Endow SA. Force generation by kinesin and myosin cytoskeletal motor proteins. J Cell Sci 2013; 126:9-19. [PMID: 23487037 DOI: 10.1242/jcs.103911] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Kinesins and myosins hydrolyze ATP, producing force that drives spindle assembly, vesicle transport and muscle contraction. How do motors do this? Here we discuss mechanisms of motor force transduction, based on their mechanochemical cycles and conformational changes observed in crystal structures. Distortion or twisting of the central β-sheet - proposed to trigger actin-induced Pi and ADP release by myosin, and microtubule-induced ADP release by kinesins - is shown in a movie depicting the transition between myosin ATP-like and nucleotide-free states. Structural changes in the switch I region form a tube that governs ATP hydrolysis and Pi release by the motors, explaining the essential role of switch I in hydrolysis. Comparison of the motor power strokes reveals that each stroke begins with the force-amplifying structure oriented opposite to the direction of rotation or swing. Motors undergo changes in their mechanochemical cycles in response to small-molecule inhibitors, several of which bind to kinesins by induced fit, trapping the motors in a state that resembles a force-producing conformation. An unusual motor activator specifically increases mechanical output by cardiac myosin, potentially providing valuable information about its mechanism of function. Further study is essential to understand motor mechanochemical coupling and energy transduction, and could lead to new therapies to treat human disease.
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Affiliation(s)
- F Jon Kull
- Department of Chemistry, Dartmouth College, Hanover, NH 03755, USA
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26
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Theisen KE, Zhmurov A, Newberry ME, Barsegov V, Dima RI. Multiscale modeling of the nanomechanics of microtubule protofilaments. J Phys Chem B 2012; 116:8545-55. [PMID: 22509945 DOI: 10.1021/jp212608f] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Large-size biomolecular systems that spontaneously assemble, disassemble, and self-repair by controlled inputs play fundamental roles in biology. Microtubules (MTs), which play important roles in cell adhesion and cell division, are a prime example. MTs serve as ″tracks″ for molecular motors, and their biomechanical functions depend on dynamic instability-a stochastic switching between periods of rapid growing and shrinking. This process is controlled by many cellular factors so that growth and shrinkage periods are correlated with the life cycle of a cell. Resolving the molecular basis for the action of these factors is of paramount importance for understanding the diverse functions of MTs. We employed a multiscale modeling approach to study the force-induced MT depolymerization by analyzing the mechanical response of a MT protofilament to external forces. We carried out self-organized polymer (SOP) model based simulations accelerated on Graphics Processing Units (GPUs). This approach enabled us to follow the mechanical behavior of the molecule on experimental time scales using experimental force loads. We resolved the structural details and determined the physical parameters that characterize the stretching and bending modes of motion of a MT protofilament. The central result is that the severing action of proteins, such as katanin and kinesin, can be understood in terms of their mechanical coupling to a protofilament. For example, the extraction of tubulin dimers from MT caps by katanin can be achieved by pushing the protofilament toward the axis of the MT cylinder, while the removal of large protofilaments curved into ″ram's horn″ structures by kinesin is the result of the outward bending of the protofilament. We showed that, at the molecular level, these types of deformations are due to the anisotropic, but homogeneous, micromechanical properties of MT protofilaments.
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Affiliation(s)
- Kelly E Theisen
- Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221, United States
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