1
|
Pradeep S, Zangle TA. LVING reveals the intracellular structure of cell growth. Sci Rep 2024; 14:8544. [PMID: 38609444 PMCID: PMC11014851 DOI: 10.1038/s41598-024-58992-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2023] [Accepted: 04/05/2024] [Indexed: 04/14/2024] Open
Abstract
The continuous balance of growth and degradation inside cells maintains homeostasis. Disturbance of this balance by internal or external factors cause state of disease, while effective disease treatments seek to restore this balance. Here, we present a method based on quantitative phase imaging (QPI) based measurements of cell mass and the velocity of mass transport to quantify the balance of growth and degradation within intracellular control volumes. The result, which we call Lagrangian velocimetry for intracellular net growth (LVING), provides high resolution maps of intracellular biomass production and degradation. We use LVING to quantify the growth in different regions of the cell during phases of the cell cycle. LVING can also be used to quantitatively compare the effect of range of chemotherapy drug doses on subcellular growth processes. Finally, we applied LVING to characterize the effect of autophagy on the growth machinery inside cells. Overall, LVING reveals both the structure and distribution of basal growth within cells, as well as the disruptions to this structure that occur during alterations in cell state.
Collapse
Affiliation(s)
- Soorya Pradeep
- Department of Chemical Engineering, University of Utah, Salt Lake City, Utah, USA
| | - Thomas A Zangle
- Department of Chemical Engineering, University of Utah, Salt Lake City, Utah, USA.
- Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah, USA.
| |
Collapse
|
2
|
Aznauryan M, Birkedal V. Dynamics of G-Quadruplex Formation under Molecular Crowding. J Phys Chem Lett 2023; 14:10354-10360. [PMID: 37948600 DOI: 10.1021/acs.jpclett.3c02453] [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: 11/12/2023]
Abstract
G-quadruplex (G4) structures assemble from guanine-rich DNA sequences and are believed to regulate several key cellular processes. G4 formation and conformational interconversions are well-established to occur dynamically in vitro. However, a clear understanding of G4 formation dynamics in cells as well as under conditions mimicking the cellular environment is missing. To fill this gap, we have investigated the G4 dynamics in molecularly crowded solutions, thus replicating the effect of the excluded volume present in cells. The results show that the volume exclusion exerted by large crowding agents accelerates the rate of G4 formation by at least an order of magnitude, leading to significant G4 stabilization. Extrapolation from our experimental data predicts crowding-induced G4 stabilization by more than 3 kcal/mol, under crowding levels found in the cellular environment. Such effects are likely to be important for G4-driven regulatory functions.
Collapse
Affiliation(s)
- Mikayel Aznauryan
- Department of Chemistry and Interdisciplinary Nanoscience Center (iNANO), Aarhus University, 8000 Aarhus C, Denmark
- Univ. Bordeaux, ARNA Laboratory, INSERM U1212, CNRS UMR 5320, Institut Européen de Chimie et Biologie, 33607 Pessac, France
| | - Victoria Birkedal
- Department of Chemistry and Interdisciplinary Nanoscience Center (iNANO), Aarhus University, 8000 Aarhus C, Denmark
| |
Collapse
|
3
|
Ma Y, Dai T, Yu L, Ma L, An S, Wang Y, Liu M, Zheng J, Kong L, Zuo C, Gao P. Reflectional quantitative differential phase microscopy using polarized wavefront phase modulation. JOURNAL OF BIOPHOTONICS 2023; 16:e202200325. [PMID: 36752421 DOI: 10.1002/jbio.202200325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 12/16/2022] [Accepted: 01/10/2023] [Indexed: 06/07/2023]
Abstract
Quantitative phase microscopy (QPM), as a label-free and nondestructive technique, has been playing an indispensable tool in biomedical imaging and industrial inspection. Herein, we introduce a reflectional quantitative differential phase microscopy (termed RQDPM) based on polarized wavefront phase modulation and partially coherent full-aperture illumination, which has high spatial resolution and spatio-temporal phase sensitivity and is applicable to opaque surfaces and turbid biological specimens. RQDPM does not require additional polarized devices and can be easily switched from reflectional mode to transmission mode. In addition, RQDPM inherits the characteristic of high axial resolution of differential interference contrast microscope, thereby providing topography for opaque surfaces. We experimentally demonstrate the reflectional phase imaging ability of RQDPM with several samples: semiconductor wafer, thick biological tissues, red blood cells, and Hela cells. Furthermore, we dynamically monitor the flow state of microspheres in a self-built microfluidic channel by using RQDPM converted into the transmission mode.
Collapse
Affiliation(s)
- Ying Ma
- School of Physics, Xidian University, Xi'an, China
| | - Taiqiang Dai
- State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Clinical Research Center for Oral Diseases, Department of Oral and Maxillofacial Surgery, School of Stomatology, The Fourth Military Medical University, Xi'an, China
| | - Lan Yu
- School of Physics, Xidian University, Xi'an, China
| | - Lin Ma
- School of Physics, Xidian University, Xi'an, China
| | - Sha An
- School of Physics, Xidian University, Xi'an, China
| | - Yang Wang
- School of Physics, Xidian University, Xi'an, China
| | - Min Liu
- School of Physics, Xidian University, Xi'an, China
| | | | - Liang Kong
- State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Clinical Research Center for Oral Diseases, Department of Oral and Maxillofacial Surgery, School of Stomatology, The Fourth Military Medical University, Xi'an, China
| | - Chao Zuo
- School of Physics, Xidian University, Xi'an, China
| | - Peng Gao
- School of Physics, Xidian University, Xi'an, China
| |
Collapse
|
4
|
A Structural Potential of Rare Trinucleotide Repeat Tracts in RNA. Int J Mol Sci 2022; 23:ijms23105850. [PMID: 35628656 PMCID: PMC9144543 DOI: 10.3390/ijms23105850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 05/17/2022] [Accepted: 05/19/2022] [Indexed: 01/27/2023] Open
Abstract
Among types of trinucleotide repeats, there is some disproportion in the frequency of their occurrence in the human exome. This research presents new data describing the folding and thermodynamic stability of short, tandem RNA repeats of 23 types, focusing on the rare, yet poorly analyzed ones. UV-melting experiments included the presence of PEG or potassium and magnesium ions to determine their effect on the stability of RNA repeats structures. Rare repeats predominantly stayed single-stranded but had the potential for base pairing with other partially complementary repeat tracts. A coexistence of suitably complementary repeat types in a single RNA creates opportunities for interaction in the context of the secondary structure of RNA. We searched the human transcriptome for model RNAs in which different, particularly rare trinucleotide repeats coexist and selected the GABRA4 and CHIC1 RNAs to study intramolecular interactions between the repeat tracts that they contain. In vitro secondary structure probing results showed that the UAA and UUG repeat tracts, present in GABRA4 3' UTR, form a double helix, which separates one of its structural domains. For the RNA CHIC1 ORF fragment containing four short AGG repeat tracts and the CGU tract, we proved the formation of quadruplexes that blocked reverse transcription.
Collapse
|
5
|
Abstract
In-cell structural biology aims at extracting structural information about proteins or nucleic acids in their native, cellular environment. This emerging field holds great promise and is already providing new facts and outlooks of interest at both fundamental and applied levels. NMR spectroscopy has important contributions on this stage: It brings information on a broad variety of nuclei at the atomic scale, which ensures its great versatility and uniqueness. Here, we detail the methods, the fundamental knowledge, and the applications in biomedical engineering related to in-cell structural biology by NMR. We finally propose a brief overview of the main other techniques in the field (EPR, smFRET, cryo-ET, etc.) to draw some advisable developments for in-cell NMR. In the era of large-scale screenings and deep learning, both accurate and qualitative experimental evidence are as essential as ever to understand the interior life of cells. In-cell structural biology by NMR spectroscopy can generate such a knowledge, and it does so at the atomic scale. This review is meant to deliver comprehensive but accessible information, with advanced technical details and reflections on the methods, the nature of the results, and the future of the field.
Collapse
Affiliation(s)
- Francois-Xavier Theillet
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France
| |
Collapse
|
6
|
Population balance modelling captures host cell protein dynamics in CHO cell cultures. PLoS One 2022; 17:e0265886. [PMID: 35320326 PMCID: PMC8959726 DOI: 10.1371/journal.pone.0265886] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 03/09/2022] [Indexed: 11/19/2022] Open
Abstract
Monoclonal antibodies (mAbs) have been extensively studied for their wide therapeutic and research applications. Increases in mAb titre has been achieved mainly by cell culture media/feed improvement and cell line engineering to increase cell density and specific mAb productivity. However, this improvement has shifted the bottleneck to downstream purification steps. The higher accumulation of the main cell-derived impurities, host cell proteins (HCPs), in the supernatant can negatively affect product integrity and immunogenicity in addition to increasing the cost of capture and polishing steps. Mathematical modelling of bioprocess dynamics is a valuable tool to improve industrial production at fast rate and low cost. Herein, a single stage volume-based population balance model (PBM) has been built to capture Chinese hamster ovary (CHO) cell behaviour in fed-batch bioreactors. Using cell volume as the internal variable, the model captures the dynamics of mAb and HCP accumulation extracellularly under physiological and mild hypothermic culture conditions. Model-based analysis and orthogonal measurements of lactate dehydrogenase activity and double-stranded DNA concentration in the supernatant show that a significant proportion of HCPs found in the extracellular matrix is secreted by viable cells. The PBM then served as a platform for generating operating strategies that optimise antibody titre and increase cost-efficiency while minimising impurity levels.
Collapse
|
7
|
Welte H, Sinn P, Kovermann M. Fluorine NMR Spectroscopy Enables to Quantify the Affinity Between DNA and Proteins in Cell Lysate. Chembiochem 2021; 22:2973-2980. [PMID: 34390111 PMCID: PMC8596521 DOI: 10.1002/cbic.202100304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Revised: 07/30/2021] [Indexed: 11/12/2022]
Abstract
The determination of the binding affinity quantifying the interaction between proteins and nucleic acids is of crucial interest in biological and chemical research. Here, we have made use of site-specific fluorine labeling of the cold shock protein from Bacillus subtilis, BsCspB, enabling to directly monitor the interaction with single stranded DNA molecules in cell lysate. High-resolution 19 F NMR spectroscopy has been applied to exclusively report on resonance signals arising from the protein under study. We have found that this experimental approach advances the reliable determination of the binding affinity between single stranded DNA molecules and its target protein in this complex biological environment by intertwining analyses based on NMR chemical shifts, signal heights, line shapes and simulations. We propose that the developed experimental platform offers a potent approach for the identification of binding affinities characterizing intermolecular interactions in native surroundings covering the nano-to-micromolar range that can be even expanded to in cell applications in future studies.
Collapse
Affiliation(s)
- Hannah Welte
- Department of ChemistryUniversity of KonstanzUniversitätsstrasse 1078467KonstanzGermany
| | - Pia Sinn
- Department of ChemistryUniversity of KonstanzUniversitätsstrasse 1078467KonstanzGermany
| | - Michael Kovermann
- Department of ChemistryUniversity of KonstanzUniversitätsstrasse 1078467KonstanzGermany
| |
Collapse
|
8
|
Kaza N, Ojaghi A, Robles FE. Hemoglobin quantification in red blood cells via dry mass mapping based on UV absorption. JOURNAL OF BIOMEDICAL OPTICS 2021; 26:JBO-210112LR. [PMID: 34378368 PMCID: PMC8353376 DOI: 10.1117/1.jbo.26.8.086501] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 07/16/2021] [Indexed: 05/31/2023]
Abstract
SIGNIFICANCE The morphological properties and hemoglobin (Hb) content of red blood cells (RBCs) are essential biomarkers to diagnose or monitor various types of hematological disorders. Label-free mass mapping approaches enable accurate Hb quantification from individual cells, serving as promising alternatives to conventional hematology analyzers. Deep ultraviolet (UV) microscopy is one such technique that allows high-resolution, molecular imaging, and absorption-based mass mapping. AIM To compare UV absorption-based mass mapping at four UV wavelengths and understand variations across wavelengths and any assumptions necessary for accurate Hb quantification. APPROACH Whole blood smears are imaged with a multispectral UV microscopy system, and the RBCs' dry masses are computed. This approach is compared to quantitative phase imaging-based mass mapping using data from an interferometric UV imaging system. RESULTS Consistent Hb mass and mean corpuscular Hb values are obtained at all wavelengths, with the precision of the single-cell mass measurements being nearly identical at 220, 260, and 280 nm but slightly lower at 300 nm. CONCLUSIONS A full hematological analysis (including white blood cell identification and characterization, and Hb quantification) may be achieved using a single UV illumination wavelength, thereby improving the speed and cost-effectiveness.
Collapse
Affiliation(s)
- Nischita Kaza
- Georgia Institute of Technology, School of Electrical and Computer Engineering, Atlanta, Georgia, United States
| | - Ashkan Ojaghi
- Georgia Institute of Technology and Emory University, Wallace H. Coulter Department of Biomedical Engineering, Atlanta, Georgia, United States
| | - Francisco E. Robles
- Georgia Institute of Technology and Emory University, Wallace H. Coulter Department of Biomedical Engineering, Atlanta, Georgia, United States
| |
Collapse
|
9
|
Davis CM, Gruebele M. Cellular Sticking Can Strongly Reduce Complex Binding by Speeding Dissociation. J Phys Chem B 2021; 125:3815-3823. [PMID: 33826329 DOI: 10.1021/acs.jpcb.1c00950] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
While extensive studies have been carried out to determine protein-RNA binding affinities, mechanisms, and dynamics in vitro, such studies do not take into consideration the effect of the many weak nonspecific interactions in a cell filled with potential binding partners. Here we experimentally tested the role of the cellular environment on affinity and binding dynamics between a protein and RNA in living U-2 OS cells. Our model system is the spliceosomal protein U1A and its binding partner SL2 of the U1 snRNA. The binding equilibrium was perturbed by a laser-induced temperature jump and monitored by Förster resonance energy transfer. The apparent binding affinity in live cells was reduced by up to 2 orders of magnitude compared to in vitro. The measured in-cell dissociation rate coefficients were up to 2 orders of magnitude larger, whereas no change in the measured association rate coefficient was observed. The latter is not what would be anticipated due to macromolecular crowding or nonspecific sticking of the uncomplexed U1A and SL2 in the cell. A quantitative model fits our experimental results, with the major cellular effect being that U1A and SL2 sticking to cellular components are capable of binding, just not as strongly as the free complex. This observation suggests that high binding affinities measured or designed in vitro are necessary for proper binding in vivo, where competition with many nonspecific interactions exists, especially for strongly interacting species with high charge or large hydrophobic surface areas.
Collapse
|
10
|
König I, Soranno A, Nettels D, Schuler B. Impact of In‐Cell and In‐Vitro Crowding on the Conformations and Dynamics of an Intrinsically Disordered Protein. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202016804] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Iwo König
- Department of Biochemistry and Department of Physics University of Zurich Winterthurerstrasse 190 8057 Zürich Switzerland
| | - Andrea Soranno
- Department of Biochemistry and Molecular Biophysics Center for Science and Engineering of Living Systems (CSELS) Washington University in St. Louis St. Louis USA
| | - Daniel Nettels
- Department of Biochemistry and Department of Physics University of Zurich Winterthurerstrasse 190 8057 Zürich Switzerland
| | - Benjamin Schuler
- Department of Biochemistry and Department of Physics University of Zurich Winterthurerstrasse 190 8057 Zürich Switzerland
| |
Collapse
|
11
|
König I, Soranno A, Nettels D, Schuler B. Impact of In-Cell and In-Vitro Crowding on the Conformations and Dynamics of an Intrinsically Disordered Protein. Angew Chem Int Ed Engl 2021; 60:10724-10729. [PMID: 33587794 DOI: 10.1002/anie.202016804] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 02/08/2021] [Indexed: 01/23/2023]
Abstract
The conformations and dynamics of proteins can be influenced by crowding from the large concentrations of macromolecules within cells. Intrinsically disordered proteins (IDPs) exhibit chain compaction in crowded solutions in vitro, but no such effects were observed in cultured mammalian cells. Here, to increase intracellular crowding, we reduced the cell volume by hyperosmotic stress and used an IDP as a crowding sensor for in-cell single-molecule spectroscopy. In these more crowded cells, the IDP exhibits compaction, slower chain dynamics, and much slower translational diffusion, indicating a pronounced concentration and length-scale dependence of crowding. In vitro, these effects cannot be reproduced with small but only with large polymeric crowders. The observations can be explained with polymer theory and depletion interactions and indicate that IDPs can diffuse much more efficiently through a crowded cytosol than a globular protein of similar dimensions.
Collapse
Affiliation(s)
- Iwo König
- Department of Biochemistry and Department of Physics, University of Zurich, Winterthurerstrasse 190, 8057, Zürich, Switzerland
| | - Andrea Soranno
- Department of Biochemistry and Molecular Biophysics, Center for Science and Engineering of Living Systems (CSELS), Washington University in St. Louis, St. Louis, USA
| | - Daniel Nettels
- Department of Biochemistry and Department of Physics, University of Zurich, Winterthurerstrasse 190, 8057, Zürich, Switzerland
| | - Benjamin Schuler
- Department of Biochemistry and Department of Physics, University of Zurich, Winterthurerstrasse 190, 8057, Zürich, Switzerland
| |
Collapse
|
12
|
Label-free spectral imaging to study drug distribution and metabolism in single living cells. Sci Rep 2021; 11:2703. [PMID: 33526869 PMCID: PMC7851119 DOI: 10.1038/s41598-021-81817-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 01/05/2021] [Indexed: 12/03/2022] Open
Abstract
During drug development, evaluation of drug and its metabolite is an essential process to understand drug activity, stability, toxicity and distribution. Liquid chromatography (LC) coupled with mass spectrometry (MS) has become the standard analytical tool for screening and identifying drug metabolites. Unlike LC/MS approach requiring liquifying the biological samples, we showed that spectral imaging (or spectral microscopy) could provide high-resolution images of doxorubicin (dox) and its metabolite doxorubicinol (dox’ol) in single living cells. Using this new method, we performed measurements without destroying the biological samples. We calculated the rate constant of dox translocating from extracellular moiety into the cell and the metabolism rate of dox to dox’ol in living cells. The translocation rate of dox into a single cell for spectral microscopy and LC/MS approaches was similar (~ 1.5 pM min−1 cell−1). When compared to spectral microscopy, the metabolism rate of dox was underestimated for about every 500 cells using LC/MS. The microscopy approach further showed that dox and dox’ol translocated to the nucleus at different rates of 0.8 and 0.3 pM min−1, respectively. LC/MS is not a practical approach to determine drug translocation from cytosol to nucleus. Using various methods, we confirmed that when combined with a high-resolution imaging, spectral characteristics of a molecule could be used as a powerful approach to analyze drug metabolism. We propose that spectral microscopy is a new method to study drug localization, translocation, transformation and identification with a resolution at a single cell level, while LC/MS is more appropriate for drug screening at an organ or tissue level.
Collapse
|
13
|
Leeb S, Yang F, Oliveberg M, Danielsson J. Connecting Longitudinal and Transverse Relaxation Rates in Live-Cell NMR. J Phys Chem B 2020; 124:10698-10707. [PMID: 33179918 PMCID: PMC7735724 DOI: 10.1021/acs.jpcb.0c08274] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 10/22/2020] [Indexed: 12/26/2022]
Abstract
In the cytosolic environment, protein crowding and Brownian motions result in numerous transient encounters. Each such encounter event increases the apparent size of the interacting molecules, leading to slower rotational tumbling. The extent of transient protein complexes formed in live cells can conveniently be quantified by an apparent viscosity, based on NMR-detected spin-relaxation measurements, that is, the longitudinal (T1) and transverse (T2) relaxation. From combined analysis of three different proteins and surface mutations thereof, we find that T2 implies significantly higher apparent viscosity than T1. At first sight, the effect on T1 and T2 seems thus nonunifiable, consistent with previous reports on other proteins. We show here that the T1 and T2 deviation is actually not a inconsistency but an expected feature of a system with fast exchange between free monomers and transient complexes. In this case, the deviation is basically reconciled by a model with fast exchange between the free-tumbling reporter protein and a transient complex with a uniform 143 kDa partner. The analysis is then taken one step further by accounting for the fact that the cytosolic content is by no means uniform but comprises a wide range of molecular sizes. Integrating over the complete size distribution of the cytosolic interaction ensemble enables us to predict both T1 and T2 from a single binding model. The result yields a bound population for each protein variant and provides a quantification of the transient interactions. We finally extend the approach to obtain a correction term for the shape of a database-derived mass distribution of the interactome in the mammalian cytosol, in good accord with the existing data of the cellular composition.
Collapse
Affiliation(s)
- Sarah Leeb
- Department of Biochemistry and Biophysics,
Arrhenius Laboratories of Natural Sciences, Stockholm University, Stockholm 106 91, Sweden
| | - Fan Yang
- Department of Biochemistry and Biophysics,
Arrhenius Laboratories of Natural Sciences, Stockholm University, Stockholm 106 91, Sweden
| | - Mikael Oliveberg
- Department of Biochemistry and Biophysics,
Arrhenius Laboratories of Natural Sciences, Stockholm University, Stockholm 106 91, Sweden
| | - Jens Danielsson
- Department of Biochemistry and Biophysics,
Arrhenius Laboratories of Natural Sciences, Stockholm University, Stockholm 106 91, Sweden
| |
Collapse
|
14
|
Abstract
Hematological analysis, via a complete blood count (CBC) and microscopy, is critical for screening, diagnosing, and monitoring blood conditions and diseases but requires complex equipment, multiple chemical reagents, laborious system calibration and procedures, and highly trained personnel for operation. Here we introduce a hematological assay based on label-free molecular imaging with deep-ultraviolet microscopy that can provide fast quantitative information of key hematological parameters to facilitate and improve hematological analysis. We demonstrate that this label-free approach yields 1) a quantitative five-part white blood cell differential, 2) quantitative red blood cell and hemoglobin characterization, 3) clear identification of platelets, and 4) detailed subcellular morphology. Analysis of tens of thousands of live cells is achieved in minutes without any sample preparation. Finally, we introduce a pseudocolorization scheme that accurately recapitulates the appearance of cells under conventional staining protocols for microscopic analysis of blood smears and bone marrow aspirates. Diagnostic efficacy is evaluated by a panel of hematologists performing a blind analysis of blood smears from healthy donors and thrombocytopenic and sickle cell disease patients. This work has significant implications toward simplifying and improving CBC and blood smear analysis, which is currently performed manually via bright-field microscopy, and toward the development of a low-cost, easy-to-use, and fast hematological analyzer as a point-of-care device and for low-resource settings.
Collapse
|
15
|
Multiplex secretome engineering enhances recombinant protein production and purity. Nat Commun 2020; 11:1908. [PMID: 32313013 PMCID: PMC7170862 DOI: 10.1038/s41467-020-15866-w] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 03/31/2020] [Indexed: 01/20/2023] Open
Abstract
Host cell proteins (HCPs) are process-related impurities generated during biotherapeutic protein production. HCPs can be problematic if they pose a significant metabolic demand, degrade product quality, or contaminate the final product. Here, we present an effort to create a "clean" Chinese hamster ovary (CHO) cell by disrupting multiple genes to eliminate HCPs. Using a model of CHO cell protein secretion, we predict that the elimination of unnecessary HCPs could have a non-negligible impact on protein production. We analyze the HCP content of 6-protein, 11-protein, and 14-protein knockout clones. These cell lines exhibit a substantial reduction in total HCP content (40%-70%). We also observe higher productivity and improved growth characteristics in specific clones. The reduced HCP content facilitates purification of a monoclonal antibody. Thus, substantial improvements can be made in protein titer and purity through large-scale HCP deletion, providing an avenue to increased quality and affordability of high-value biopharmaceuticals.
Collapse
|
16
|
Ogunmoyole T, Adewale IO, Fodeke AA, Afolayan A. Catalytic studies of glutathione transferase from Clarias gariepinus (Burchell) in dilute and crowded solutions. Comp Biochem Physiol C Toxicol Pharmacol 2020; 228:108648. [PMID: 31672530 DOI: 10.1016/j.cbpc.2019.108648] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 10/17/2019] [Accepted: 10/22/2019] [Indexed: 10/25/2022]
Abstract
Kinetic properties of purified Clarias gariepinus glutathione transferase (CgGST) was studied in the presence of Ficoll 70, Polyethylene glycol (PEG) 6000, bovine serum albumin (BSA) and in dilute solution. This was done to mimic the cytosol thereby unraveling the actual mechanism of detoxication involving glutathione transferase (GST) in the crowded intracellular milieu. CgGST from the liver of Clarias gariepinus was purified to homogeneity by affinity chromatography on glutathione (GSH) - agarose. Initial-velocity study was performed by varying the concentrations of GSH at various fixed concentrations of 1-chloro-2,4-dinitrobenzene (CDNB) and vice-versa. Data obtained were fitted to the three equations representing random-ordered, compulsory-ordered and ping-pong mechanisms to obtain kinetic parameters. Product inhibition studies using sodium chloride (NaCl) was done by varying the concentrations of NaCl and CDNB at a fixed concentration of GSH and vice-versa. Data obtained were fitted to three equations representing competitive, non-competitive and uncompetitive inhibitions to obtain the inhibition constants (KiGSH and KiCDNB). Optimal temperature of CgGST activity was 20 °C both in dilute and crowded solutions. Maximum velocity (Vmax) in dilute solution was decreased, while KmGSH and KmCDNB were increased in the presence of the crowding agents. Turnover number (kcat), catalytic efficiency - kcat/KmGSH,kcat/KmCDNB and inhibition constants - (KiGSH and KiCDNB) were reduced in crowded solutions. Mechanism of catalysis was steady - state random sequential in both dilute and crowded solutions. The study concluded that although the catalytic efficiency of the enzyme was reduced in crowded solution, mechanism of catalysis remains the same in both crowded and dilute solutions.
Collapse
Affiliation(s)
- Temidayo Ogunmoyole
- Department of Medical Biochemistry, College of Medicine, Ekiti State University, Ado-Ekiti, Nigeria.
| | - Isaac Olusanjo Adewale
- Department of Biochemistry and Molecular Biology, Obafemi Awolowo University, Ile-Ife 220282, Nigeria.
| | - Adedayo A Fodeke
- Department of Chemistry, Obafemi Awolowo, University, Ile-Ife 220282, Nigeria
| | - Adeyinka Afolayan
- Department of Biochemistry and Molecular Biology, Obafemi Awolowo University, Ile-Ife 220282, Nigeria
| |
Collapse
|
17
|
Litberg TJ, Docter B, Hughes MP, Bourne J, Horowitz S. DNA Facilitates Oligomerization and Prevents Aggregation via DNA Networks. Biophys J 2019; 118:162-171. [PMID: 31839258 DOI: 10.1016/j.bpj.2019.11.022] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 10/11/2019] [Accepted: 11/05/2019] [Indexed: 12/12/2022] Open
Abstract
Previous studies have shown that nucleic acids can nucleate protein aggregation in disease-related proteins, but in other cases, they can act as molecular chaperones that prevent protein aggregation, even under extreme conditions. In this study, we describe the link between these two behaviors through a combination of electron microscopy and aggregation kinetics. We find that two different proteins become soluble under harsh conditions through oligomerization with DNA. These DNA/protein oligomers form "networks," which increase the speed of oligomerization. The cases of DNA both increasing and preventing protein aggregation are observed to stem from this enhanced oligomerization. This observation raises interesting questions about the role of nucleic acids in aggregate formation in disease states.
Collapse
Affiliation(s)
- Theodore J Litberg
- Department of Chemistry & Biochemistry, Knoebel Institute for Healthy Aging, University of Denver, Denver, Colorado
| | - Brianne Docter
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, Michigan
| | - Michael P Hughes
- Department of Biological Chemistry, University of California, Los Angeles, Los Angeles, California; Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California; Howard Hughes Medical Institute, University of California, Los Angeles, Los Angeles, California; Department of Energy, University of California, Los Angeles, Los Angeles, California; Institute for Genomics and Proteomics, University of California, Los Angeles, Los Angeles, California
| | - Jennifer Bourne
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, Colorado
| | - Scott Horowitz
- Department of Chemistry & Biochemistry, Knoebel Institute for Healthy Aging, University of Denver, Denver, Colorado.
| |
Collapse
|
18
|
A new perspective on membrane-embedded Bax oligomers using DEER and bioresistant orthogonal spin labels. Sci Rep 2019; 9:13013. [PMID: 31506457 PMCID: PMC6737250 DOI: 10.1038/s41598-019-49370-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 08/20/2019] [Indexed: 12/23/2022] Open
Abstract
Bax is a Bcl-2 protein crucial for apoptosis initiation and execution, whose active conformation is only partially understood. Dipolar EPR spectroscopy has proven to be a valuable tool to determine coarse-grained models of membrane-embedded Bcl-2 proteins. Here we show how the combination of spectroscopically distinguishable nitroxide and gadolinium spin labels and Double Electron-Electron Resonance can help to gain new insights into the quaternary structure of active, membrane-embedded Bax oligomers. We show that attaching labels bulkier than the conventional MTSL may affect Bax fold and activity, depending on the protein/label combination. However, we identified a suitable pair of spectroscopically distinguishable labels, which allows to study complex distance networks in the oligomers that could not be disentangled before. Additionally, we compared the stability of the different spin-labeled protein variants in E. coli and HeLa cell extracts. We found that the gem-diethyl nitroxide-labeled Bax variants were reasonably stable in HeLa cell extracts. However, when transferred into human cells, Bax was found to be mislocalized, thus preventing its characterization in a physiological environment. The successful use of spectroscopically distinguishable labels on membrane-embedded Bax-oligomers opens an exciting new path towards structure determination of membrane-embedded homo- or hetero-oligomeric Bcl-2 proteins via EPR.
Collapse
|
19
|
Siegal G, Selenko P. Cells, drugs and NMR. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2019; 306:202-212. [PMID: 31358370 DOI: 10.1016/j.jmr.2019.07.018] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2019] [Revised: 06/08/2019] [Accepted: 07/08/2019] [Indexed: 05/18/2023]
Abstract
Nuclear magnetic resonance (NMR) spectroscopy is a versatile tool for investigating cellular structures and their compositions. While in vivo and whole-cell NMR have a long tradition in cell-based approaches, high-resolution in-cell NMR spectroscopy is a new addition to these methods. In recent years, technological advancements in multiple areas provided converging benefits for cellular MR applications, especially in terms of robustness, reproducibility and physiological relevance. Here, we review the use of cellular NMR methods for drug discovery purposes in academia and industry. Specifically, we discuss how developments in NMR technologies such as miniaturized bioreactors and flow-probe perfusion systems have helped to consolidate NMR's role in cell-based drug discovery efforts.
Collapse
Affiliation(s)
- Gregg Siegal
- ZoBio B.V., BioPartner 2 Building, J.H. Oortweg 19, 2333 Leiden, the Netherlands
| | - Philipp Selenko
- Department of Biological Regulation, Weizmann Institute of Science, 234 Herzl Street, 761000 Rehovot, Israel.
| |
Collapse
|
20
|
Lammel T, Mackevica A, Johansson BR, Sturve J. Endocytosis, intracellular fate, accumulation, and agglomeration of titanium dioxide (TiO 2) nanoparticles in the rainbow trout liver cell line RTL-W1. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2019; 26:15354-15372. [PMID: 30929178 PMCID: PMC6529399 DOI: 10.1007/s11356-019-04856-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Accepted: 03/13/2019] [Indexed: 06/01/2023]
Abstract
There is increasing evidence that titanium dioxide (TiO2) nanoparticles (NPs) present in water or diet can be taken up by fish and accumulate in internal organs including the liver. However, their further fate in the organ is unknown. This study provides new insights into the interaction, uptake mechanism, intracellular trafficking, and fate of TiO2 NPs (Aeroxide® P25) in fish liver parenchymal cells (RTL-W1) in vitro using high-resolution transmission electron microscopy (TEM) and single particle inductively coupled plasma mass spectrometry (spICP-MS) as complementary analytical techniques. The results demonstrate that following their uptake via caveolae-mediated endocytosis, TiO2 NPs were trafficked through different intracellular compartments including early endosomes, multivesicular bodies, and late endosomes/endo-lysosomes, and eventually concentrated inside multilamellar vesicles. TEM and spICP-MS results provide evidence that uptake was nano-specific. Only NPs/NP agglomerates of a specific size range (~ 30-100 nm) were endocytosed; larger agglomerates were excluded from uptake and remained located in the extracellular space/exposure medium. NP number and mass inside cells increased linearly with time and was associated with an increase in particle diameter suggesting intracellular agglomeration/aggregation. No alterations in the expression of genes regulated by the redox balance-sensitive transcription factor Nrf-2 including superoxide dismutase, glutamyl cysteine ligase, glutathione synthetase, glutathione peroxidase, and glutathione S-transferase were observed. This shows that, despite the high intracellular NP burden (~ 3.9 × 102 ng Ti/mg protein after 24 h) and NP-interaction with mitochondria, cellular redox homeostasis was not significantly affected. This study contributes to a better mechanistic understanding of in vitro particokinetics as well as the potential fate and effects of TiO2 NPs in fish liver cells.
Collapse
Affiliation(s)
- Tobias Lammel
- Department of Biological and Environmental Sciences, University of Gothenburg, Box 463, 413 90, Göteborg, Sweden.
| | - Aiga Mackevica
- DTU Environment, Technical University of Denmark, 2800, Kongens Lyngby, Denmark
| | - Bengt R Johansson
- The Electron Microscopy Unit, Institute of Biomedicine, Sahlgrenska Academy at University of Gothenburg, 405 30, Göteborg, Sweden
| | - Joachim Sturve
- Department of Biological and Environmental Sciences, University of Gothenburg, Box 463, 413 90, Göteborg, Sweden
| |
Collapse
|
21
|
Fulka H, Langerova A. Nucleoli in embryos: a central structural platform for embryonic chromatin remodeling? Chromosome Res 2018; 27:129-140. [PMID: 30406864 DOI: 10.1007/s10577-018-9590-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 10/17/2018] [Accepted: 10/24/2018] [Indexed: 10/27/2022]
Abstract
Nucleoli are the site of ribosomal RNA production and subunit assembly. In contrast to active nucleoli in somatic cells, where three basic sub-compartments can be observed, mammalian oocytes and early embryos contain atypical nucleoli termed "nucleolus-like bodies" or "nucleolus precursor bodies", respectively. Unlike their somatic counterparts, these structures are composed of dense homogenous fibrillar material and exhibit no polymerase activity. Irrespective of these unusual properties, they have been shown to be absolutely essential for embryonic development, as their microsurgical removal results in developmental arrest. Historically, nucleolus-like and nucleolus precursor bodies have been perceived as passive storage sites of nucleolar material, which is gradually utilized by embryos to construct fully functional nucleoli once they have activated their genome and have started to produce ribosomes. For decades, researchers have been trying to elucidate the composition of these organelles and provide the evidence for their repository role. However, only recently has it become clear that the function of these atypical nucleoli is altogether different, and rather than being involved in ribosome biogenesis, they participate in parental chromatin remodeling, and strikingly, the artificial introduction of a single NPB component is sufficient to rescue the developmental arrest elicited by the NPB removal. In this review, we will describe and summarize the experiments that led to the change in our understanding of these unique structures.
Collapse
Affiliation(s)
- Helena Fulka
- Institute of Animal Science, v.v.i., 104 00, Prague 10, Czech Republic. .,Institute of Molecular Genetics ASCR, v.v.i., 142 20, Prague 4, Czech Republic. .,Institute of Experimental Medicine ASCR, v.v.i., 142 20, Prague 4, Czech Republic.
| | | |
Collapse
|
22
|
Abstract
Ultraviolet (UV) spectroscopy is a powerful tool for quantitative (bio)chemical analysis, but its application to molecular imaging and microscopy has been limited. Here we introduce ultraviolet hyperspectral interferometric (UHI) microscopy, which leverages coherent detection of optical fields to overcome significant challenges associated with UV spectroscopy when applied to molecular imaging. We demonstrate that this method enables quantitative spectral analysis of important endogenous biomolecules with subcellular spatial resolution and sensitivity to nanometer-scaled structures for label-free molecular imaging of live cells.
Collapse
|
23
|
Duranthon V, Chavatte-Palmer P. Long term effects of ART: What do animals tell us? Mol Reprod Dev 2018; 85:348-368. [DOI: 10.1002/mrd.22970] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 02/09/2018] [Indexed: 01/01/2023]
|
24
|
McNamara G, Difilippantonio M, Ried T, Bieber FR. Microscopy and Image Analysis. ACTA ACUST UNITED AC 2018; 94:4.4.1-4.4.89. [DOI: 10.1002/cphg.42] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
| | - Michael Difilippantonio
- Division of Cancer Treatment and Diagnosis National Cancer Institute, National Institutes of Health Bethesda Maryland
| | - Thomas Ried
- Section of Cancer Genomics Genetics Branch Center for Cancer Research National Cancer Institute, National Institutes of Health Bethesda Maryland
| | | |
Collapse
|
25
|
Model MA, Petruccelli JC. Intracellular Macromolecules in Cell Volume Control and Methods of Their Quantification. CURRENT TOPICS IN MEMBRANES 2018; 81:237-289. [DOI: 10.1016/bs.ctm.2018.06.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
|
26
|
Acosta LC, Perez Goncalves GM, Pielak GJ, Gorensek-Benitez AH. Large cosolutes, small cosolutes, and dihydrofolate reductase activity. Protein Sci 2017; 26:2417-2425. [PMID: 28971539 DOI: 10.1002/pro.3316] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 09/27/2017] [Accepted: 09/27/2017] [Indexed: 11/06/2022]
Abstract
Protein enzymes are the main catalysts in the crowded and complex cellular interior, but their activity is almost always studied in dilute buffered solutions. Studies that attempt to recreate the cellular interior in vitro often utilize synthetic polymers as crowding agents. Here, we report the effects of the synthetic polymer cosolutes Ficoll, dextran, and polyvinylpyrrolidone, and their respective monomers, sucrose, glucose, and 1-ethyl-2-pyrrolidone, on the activity of the 18-kDa monomeric enzyme, Escherichia coli dihydrofolate reductase. At low concentrations, reductase activity increases relative to buffer and monomers, suggesting a macromolecular effect. However, the effect decreases at higher concentrations, approaching, and, in some cases, falling below buffer values. We also assessed activity in terms of volume occupancy, viscosity, and the overlap concentration (where polymers form an interwoven mesh). The trends vary with polymer family, but changes in activity are within threefold of buffer values. We also compiled and analyzed results from previous studies and conclude that alterations of steady-state enzyme kinetics in solutions crowded with synthetic polymers are idiosyncratic with respect to the crowding agent and enzyme.
Collapse
Affiliation(s)
| | | | - Gary J Pielak
- Department of Chemistry.,Department of Biochemistry and Biophysics.,Lineberger Comprehensive Cancer Center.,Integrative Program for Biological and Genome Sciences University of North Carolina, Chapel Hill, NC, 27599, USA
| | | |
Collapse
|
27
|
Abriata LA, Spiga E, Peraro MD. Molecular Effects of Concentrated Solutes on Protein Hydration, Dynamics, and Electrostatics. Biophys J 2017; 111:743-755. [PMID: 27558718 DOI: 10.1016/j.bpj.2016.07.011] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 06/06/2016] [Accepted: 07/05/2016] [Indexed: 12/20/2022] Open
Abstract
Most studies of protein structure and function are performed in dilute conditions, but proteins typically experience high solute concentrations in their physiological scenarios and biotechnological applications. High solute concentrations have well-known effects on coarse protein traits like stability, diffusion, and shape, but likely also perturb other traits through finer effects pertinent at the residue and atomic levels. Here, NMR and molecular dynamics investigations on ubiquitin disclose variable interactions with concentrated solutes that lead to localized perturbations of the protein's surface, hydration, electrostatics, and dynamics, all dependent on solute size and chemical properties. Most strikingly, small polar uncharged molecules are sticky on the protein surface, whereas charged small molecules are not, but the latter still perturb the internal protein electrostatics as they diffuse nearby. Meanwhile, interactions with macromolecular crowders are favored mainly through hydrophobic, but not through polar, surface patches. All the tested small solutes strongly slow down water exchange at the protein surface, whereas macromolecular crowders do not exert such strong perturbation. Finally, molecular dynamics simulations predict that unspecific interactions slow down microsecond- to millisecond-timescale protein dynamics despite having only mild effects on pico- to nanosecond fluctuations as corroborated by NMR. We discuss our results in the light of recent advances in understanding proteins inside living cells, focusing on the physical chemistry of quinary structure and cellular organization, and we reinforce the idea that proteins should be studied in native-like media to achieve a faithful description of their function.
Collapse
Affiliation(s)
- Luciano A Abriata
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne and Swiss Institute of Bioinformatics, Lausanne, Switzerland.
| | - Enrico Spiga
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne and Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Matteo Dal Peraro
- Institute of Bioengineering, School of Life Sciences, École Polytechnique Fédérale de Lausanne and Swiss Institute of Bioinformatics, Lausanne, Switzerland.
| |
Collapse
|
28
|
Kawata S, Ichimura T, Taguchi A, Kumamoto Y. Nano-Raman Scattering Microscopy: Resolution and Enhancement. Chem Rev 2017; 117:4983-5001. [PMID: 28337915 DOI: 10.1021/acs.chemrev.6b00560] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Raman scattering microscopy is becoming one of the hot topics in analytical microscopy as a tool for analyzing advanced nanomaterials, such as biomolecules in a live cell for the study of cellular dynamics, semiconductor devices for characterizing strain distribution and contamination, and nanocarbons and nano-2D materials. In this paper, we review the recent progress in the development of Raman scattering microscopy from the viewpoint of spatial resolution and scattering efficiency. To overcome the extremely small cross section of Raman scattering, we discuss three approaches for the enhancement of scattering efficiency and show that the scattering enhancement synergistically increases the spatial resolution. We discuss the mechanisms of tip-enhanced Raman scattering, deep-UV resonant Raman scattering, and coherent nonlinear Raman scattering for micro- and nanoscope applications. The combinations of these three approaches are also shown as nanometer-resolution Raman scattering microscopy. The critical issues of the structures, materials, and reproducibility of tips and three-dimensionality for TERS; photodegradation for resonant Raman scattering; and laser availability for coherent nonlinear Raman scattering are also discussed.
Collapse
Affiliation(s)
- Satoshi Kawata
- Department of Applied Physics, Osaka University , Osaka 565-0871, Japan
| | - Taro Ichimura
- Quantitative Biology Center, RIKEN , Osaka 565-0874, Japan
| | - Atsushi Taguchi
- Department of Applied Physics, Osaka University , Osaka 565-0871, Japan
| | - Yasuaki Kumamoto
- Department of Pathology and Cell Regulation, Kyoto Prefectural University of Medicine , Kyoto 602-8566, Japan
| |
Collapse
|
29
|
Computational On-Chip Imaging of Nanoparticles and Biomolecules using Ultraviolet Light. Sci Rep 2017; 7:44157. [PMID: 28276489 PMCID: PMC5343455 DOI: 10.1038/srep44157] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 02/02/2017] [Indexed: 12/28/2022] Open
Abstract
Significant progress in characterization of nanoparticles and biomolecules was enabled by the development of advanced imaging equipment with extreme spatial-resolution and sensitivity. To perform some of these analyses outside of well-resourced laboratories, it is necessary to create robust and cost-effective alternatives to existing high-end laboratory-bound imaging and sensing equipment. Towards this aim, we have designed a holographic on-chip microscope operating at an ultraviolet illumination wavelength (UV) of 266 nm. The increased forward scattering from nanoscale objects at this short wavelength has enabled us to detect individual sub-30 nm nanoparticles over a large field-of-view of >16 mm2 using an on-chip imaging platform, where the sample is placed at ≤0.5 mm away from the active area of an opto-electronic sensor-array, without any lenses in between. The strong absorption of this UV wavelength by biomolecules including nucleic acids and proteins has further enabled high-contrast imaging of nanoscopic aggregates of biomolecules, e.g., of enzyme Cu/Zn-superoxide dismutase, abnormal aggregation of which is linked to amyotrophic lateral sclerosis (ALS) - a fatal neurodegenerative disease. This UV-based wide-field computational imaging platform could be valuable for numerous applications in biomedical sciences and environmental monitoring, including disease diagnostics, viral load measurements as well as air- and water-quality assessment.
Collapse
|
30
|
Cohen RD, Pielak GJ. A cell is more than the sum of its (dilute) parts: A brief history of quinary structure. Protein Sci 2017; 26:403-413. [PMID: 27977883 PMCID: PMC5326556 DOI: 10.1002/pro.3092] [Citation(s) in RCA: 94] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Revised: 12/02/2016] [Accepted: 12/02/2016] [Indexed: 01/01/2023]
Abstract
Most knowledge of protein structure and function is derived from experiments performed with purified protein resuspended in dilute, buffered solutions. However, proteins function in the crowded, complex cellular environment. Although the first four levels of protein structure provide important information, a complete understanding requires consideration of quinary structure. Quinary structure comprises the transient interactions between macromolecules that provides organization and compartmentalization inside cells. We review the history of quinary structure in the context of several metabolic pathways, and the technological advances that have yielded recent insight into protein behavior in living cells. The evidence demonstrates that protein behavior in isolated solutions deviates from behavior in the physiological environment.
Collapse
Affiliation(s)
- Rachel D. Cohen
- Department of ChemistryUniversity of North CarolinaChapel HillNorth Carolina27599
| | - Gary J. Pielak
- Department of ChemistryUniversity of North CarolinaChapel HillNorth Carolina27599
- Department of Biochemistry and BiophysicsUniversity of North CarolinaChapel HillNorth Carolina27599
- Lineberger Comprehensive Cancer Center, University of North CarolinaChapel HillNorth Carolina27599
| |
Collapse
|
31
|
Kumamoto Y, Fujita K, Smith NI, Kawata S. Deep-UV biological imaging by lanthanide ion molecular protection. BIOMEDICAL OPTICS EXPRESS 2016; 7:158-70. [PMID: 26819825 PMCID: PMC4722900 DOI: 10.1364/boe.7.000158] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Revised: 12/08/2015] [Accepted: 12/11/2015] [Indexed: 05/05/2023]
Abstract
Deep-UV (DUV) light is a sensitive probe for biological molecules such as nucleobases and aromatic amino acids due to specific absorption. However, the use of DUV light for imaging is limited because DUV can destroy or denature target molecules in a sample. Here we show that trivalent ions in the lanthanide group can suppress molecular photodegradation under DUV exposure, enabling a high signal-to-noise ratio and repetitive DUV imaging of nucleobases in cells. Underlying mechanisms of the photodegradation suppression can be excitation relaxation of the DUV-absorptive molecules due to energy transfer to the lanthanide ions, and/or avoiding ionization and reactions with surrounding molecules, including generation of reactive oxygen species, which can modify molecules that are otherwise transparent to DUV light. This approach, directly removing excited energy at the fundamental origin of cellular photodegradation, indicates an important first step towards the practical use of DUV imaging in a variety of biological applications.
Collapse
Affiliation(s)
- Yasuaki Kumamoto
- Department of Applied Physics, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
- Near-field Nanophotonics Research Team, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- Currently with the Department of Pathology and Cell Regulation, Kyoto Prefectural University of Medicine, 465 Kajii-cho Kawaramachi-Hirokoji, Kamigyo-ku, Kyoto 602-8566, Japan
| | - Katsumasa Fujita
- Department of Applied Physics, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Nicholas Isaac Smith
- Immunology Frontier Research Center, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Satoshi Kawata
- Department of Applied Physics, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
- Near-field Nanophotonics Research Team, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| |
Collapse
|
32
|
Cravens SL, Schonhoft JD, Rowland MM, Rodriguez AA, Anderson BG, Stivers JT. Molecular crowding enhances facilitated diffusion of two human DNA glycosylases. Nucleic Acids Res 2015; 43:4087-97. [PMID: 25845592 PMCID: PMC4417188 DOI: 10.1093/nar/gkv301] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 03/27/2015] [Indexed: 12/22/2022] Open
Abstract
Intracellular space is at a premium due to the high concentrations of biomolecules and is expected to have a fundamental effect on how large macromolecules move in the cell. Here, we report that crowded solutions promote intramolecular DNA translocation by two human DNA repair glycosylases. The crowding effect increases both the efficiency and average distance of DNA chain translocation by hindering escape of the enzymes to bulk solution. The increased contact time with the DNA chain provides for redundant damage patrolling within individual DNA chains at the expense of slowing the overall rate of damaged base removal from a population of molecules. The significant biological implication is that a crowded cellular environment could influence the mechanism of damage recognition as much as any property of the enzyme or DNA.
Collapse
Affiliation(s)
- Shannen L Cravens
- Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, 725 North Wolfe Street, Baltimore, MD 21205-2185, USA
| | - Joseph D Schonhoft
- Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, 725 North Wolfe Street, Baltimore, MD 21205-2185, USA
| | - Meng M Rowland
- Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, 725 North Wolfe Street, Baltimore, MD 21205-2185, USA
| | - Alyssa A Rodriguez
- Department of Chemistry and Biochemistry, The University of San Diego, 5998 Alcalá Park, San Diego, CA 92110, USA
| | - Breeana G Anderson
- Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, 725 North Wolfe Street, Baltimore, MD 21205-2185, USA
| | - James T Stivers
- Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, 725 North Wolfe Street, Baltimore, MD 21205-2185, USA
| |
Collapse
|
33
|
Tárnok A. The year of light for enlightening photonics and cytometry- start of new year's note. Cytometry A 2014; 87:1-2. [DOI: 10.1002/cyto.a.22606] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Accepted: 12/01/2014] [Indexed: 02/06/2023]
Affiliation(s)
- Attila Tárnok
- Department of Pediatric Cardiology; Heart Centre Leipzig, University of Leipzig; Leipzig Germany
- Translational Centre for Regenerative Medicine (TRM), University of Leipzig; Leipzig Germany
| |
Collapse
|
34
|
Zangle TA, Teitell MA. Live-cell mass profiling: an emerging approach in quantitative biophysics. Nat Methods 2014; 11:1221-8. [PMID: 25423019 PMCID: PMC4319180 DOI: 10.1038/nmeth.3175] [Citation(s) in RCA: 150] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Accepted: 07/22/2014] [Indexed: 12/16/2022]
Abstract
Cell mass, volume and growth rate are tightly controlled biophysical parameters in cellular development and homeostasis, and pathological cell growth defines cancer in metazoans. The first measurements of cell mass were made in the 1950s, but only recently have advances in computer science and microfabrication spurred the rapid development of precision mass-quantifying approaches. Here we discuss available techniques for quantifying the mass of single live cells with an emphasis on relative features, capabilities and drawbacks for different applications.
Collapse
Affiliation(s)
- Thomas A Zangle
- Department of Bioengineering, University of California, Los Angeles (UCLA), Los Angeles, California, USA
| | - Michael A Teitell
- 1] Department of Bioengineering, University of California, Los Angeles (UCLA), Los Angeles, California, USA. [2] Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California, USA. [3] California NanoSystems Institute, UCLA, Los Angeles, California, USA. [4] Broad Stem Cell Research Center, UCLA, Los Angeles, California, USA. [5] Jonsson Comprehensive Cancer Center, UCLA, Los Angeles, California, USA. [6] Molecular Biology Institute, UCLA, Los Angeles, California, USA
| |
Collapse
|
35
|
Martorana A, Bellapadrona G, Feintuch A, Di Gregorio E, Aime S, Goldfarb D. Probing protein conformation in cells by EPR distance measurements using Gd3+ spin labeling. J Am Chem Soc 2014; 136:13458-65. [PMID: 25163412 DOI: 10.1021/ja5079392] [Citation(s) in RCA: 165] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Protein structure investigations are usually carried out in vitro under conditions far from their native environment in the cell. Differences between in-cell and in vitro structures of proteins can be generated by crowding effects, local pH changes, specific and nonspecific protein and ligand binding events, and chemical modifications. Double electron-electron resonance (DEER), in conjunction with site-directed spin-labeling, has emerged in the past decade as a powerful technique for exploring protein conformations in frozen solutions. The major challenges facing the application of this methodology to in-cell measurements are the instabilities of the standard nitroxide spin labels in the cell environment and the limited sensitivity at conventional X-band frequencies. We present a new approach for in-cell DEER distance measurement in human cells, based on the use of: (i) reduction resistant Gd(3+) chelates as spin labels, (ii) high frequency (94.9 GHz) for sensitivity enhancement, and (iii) hypo-osmotic shock for efficient delivery of the labeled protein into the cell. The proof of concept is demonstrated on doubly labeled ubiquitin in HeLa cells.
Collapse
Affiliation(s)
- Andrea Martorana
- Department of Chemical Physics and ‡Department of Materials and Interfaces, Weizmann Institute of Science , Rehovot, Israel 7610001
| | | | | | | | | | | |
Collapse
|
36
|
Theillet FX, Binolfi A, Frembgen-Kesner T, Hingorani K, Sarkar M, Kyne C, Li C, Crowley PB, Gierasch L, Pielak GJ, Elcock AH, Gershenson A, Selenko P. Physicochemical properties of cells and their effects on intrinsically disordered proteins (IDPs). Chem Rev 2014; 114:6661-714. [PMID: 24901537 PMCID: PMC4095937 DOI: 10.1021/cr400695p] [Citation(s) in RCA: 326] [Impact Index Per Article: 32.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Indexed: 02/07/2023]
Affiliation(s)
- Francois-Xavier Theillet
- Department
of NMR-supported Structural Biology, In-cell NMR Laboratory, Leibniz Institute of Molecular Pharmacology (FMP Berlin), Robert-Roessle Strasse 10, 13125 Berlin, Germany
| | - Andres Binolfi
- Department
of NMR-supported Structural Biology, In-cell NMR Laboratory, Leibniz Institute of Molecular Pharmacology (FMP Berlin), Robert-Roessle Strasse 10, 13125 Berlin, Germany
| | - Tamara Frembgen-Kesner
- Department
of Biochemistry, University of Iowa, Bowen Science Building, 51 Newton
Road, Iowa City, Iowa 52242, United States
| | - Karan Hingorani
- Departments
of Biochemistry & Molecular Biology and Chemistry, Program in
Molecular & Cellular Biology, University
of Massachusetts, Amherst, 240 Thatcher Way, Amherst, Massachusetts 01003, United States
| | - Mohona Sarkar
- Department
of Chemistry, Department of Biochemistry and Biophysics and Lineberger
Comprehensive Cancer Center, University
of North Carolina, Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States
| | - Ciara Kyne
- School
of Chemistry, National University of Ireland,
Galway, University Road, Galway, Ireland
| | - Conggang Li
- Key Laboratory
of Magnetic Resonance in Biological Systems, State Key Laboratory
of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Center
for Magnetic Resonance, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan, 430071, P.R. China
| | - Peter B. Crowley
- School
of Chemistry, National University of Ireland,
Galway, University Road, Galway, Ireland
| | - Lila Gierasch
- Departments
of Biochemistry & Molecular Biology and Chemistry, Program in
Molecular & Cellular Biology, University
of Massachusetts, Amherst, 240 Thatcher Way, Amherst, Massachusetts 01003, United States
| | - Gary J. Pielak
- Department
of Chemistry, Department of Biochemistry and Biophysics and Lineberger
Comprehensive Cancer Center, University
of North Carolina, Chapel Hill, Chapel Hill, North Carolina 27599-3290, United States
| | - Adrian H. Elcock
- Department
of Biochemistry, University of Iowa, Bowen Science Building, 51 Newton
Road, Iowa City, Iowa 52242, United States
| | - Anne Gershenson
- Departments
of Biochemistry & Molecular Biology and Chemistry, Program in
Molecular & Cellular Biology, University
of Massachusetts, Amherst, 240 Thatcher Way, Amherst, Massachusetts 01003, United States
| | - Philipp Selenko
- Department
of NMR-supported Structural Biology, In-cell NMR Laboratory, Leibniz Institute of Molecular Pharmacology (FMP Berlin), Robert-Roessle Strasse 10, 13125 Berlin, Germany
| |
Collapse
|
37
|
Brison DR, Sturmey RG, Leese HJ. Metabolic heterogeneity during preimplantation development: the missing link? Hum Reprod Update 2014; 20:632-40. [DOI: 10.1093/humupd/dmu018] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
|
38
|
|