1
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Bienau A, Jäkel AC, Simmel FC. Cell-Free Gene Expression in Bioprinted Fluidic Networks. ACS Synth Biol 2024; 13:2447-2456. [PMID: 39042670 PMCID: PMC11334185 DOI: 10.1021/acssynbio.4c00187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Revised: 07/01/2024] [Accepted: 07/09/2024] [Indexed: 07/25/2024]
Abstract
The realization of soft robotic devices with life-like properties requires the engineering of smart, active materials that can respond to environmental cues in similar ways as living cells or organisms. Cell-free expression systems provide an approach for embedding dynamic molecular control into such materials that avoids many of the complexities associated with genuinely living systems. Here, we present a strategy to integrate cell-free protein synthesis within agarose-based hydrogels that can be spatially organized and supplied by a synthetic vasculature. We first utilize an indirect printing approach with a commercial bioprinter and Pluronic F-127 as a fugitive ink to define fluidic channel structures within the hydrogels. We then investigate the impact of the gel matrix on the expression of proteins in E. coli cell-extract, which is found to depend on the gel density and the dilution of the expression system. When supplying the vascularized hydrogels with reactants, larger components such as DNA plasmids are confined to the channels or immobilized in the gels while nanoscale reaction components can diffusively spread within the gel. Using a single supply channel, we demonstrate different spatial protein concentration profiles emerging from different cell-free gene circuits comprising production, gene activation, and negative feedback. Variation of the channel design allows the creation of specific concentration profiles such as a long-term stable gradient or the homogeneous supply of a hydrogel with proteins.
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Affiliation(s)
- Alexandra Bienau
- TU Munich, School of Natural Sciences, Department of Bioscience, 85748 Garching
b. München, Germany
| | - Anna C. Jäkel
- TU Munich, School of Natural Sciences, Department of Bioscience, 85748 Garching
b. München, Germany
| | - Friedrich C. Simmel
- TU Munich, School of Natural Sciences, Department of Bioscience, 85748 Garching
b. München, Germany
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2
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Swanson P, Arnold GP, Curley CE, Wakita SC, Waters JDV, Balog ERM. Understanding the Phase Behavior of a Multistimuli-Responsive Elastin-like Polymer: Insights from Dynamic Light Scattering Analysis. J Phys Chem B 2024; 128:5756-5765. [PMID: 38830627 PMCID: PMC11181320 DOI: 10.1021/acs.jpcb.4c00070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Revised: 04/08/2024] [Accepted: 04/30/2024] [Indexed: 06/05/2024]
Abstract
Elastin-like polymers are a class of stimuli-responsive protein polymers that hold immense promise in applications such as drug delivery, hydrogels, and biosensors. Yet, understanding the intricate interplay of factors influencing their stimuli-responsive behavior remains a challenging frontier. Using temperature-controlled dynamic light scattering and zeta potential measurements, we investigate the interactions between buffer, pH, salt, water, and protein using an elastin-like polymer containing ionizable lysine residues. We observed the elevation of transition temperature in the presence of the common buffering agent HEPES at low concentrations, suggesting a "salting-in" effect of HEPES as a cosolute through weak association with the protein. Our findings motivate a more comprehensive investigation of the influence of buffer and other cosolute molecules on elastin-like polymer behavior.
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Affiliation(s)
- Peter
C. Swanson
- School of Mathematical and
Physical Sciences, University of New England, Biddeford, Maine 04005, United States
| | - Galen P. Arnold
- School of Mathematical and
Physical Sciences, University of New England, Biddeford, Maine 04005, United States
| | - Carolyn E. Curley
- School of Mathematical and
Physical Sciences, University of New England, Biddeford, Maine 04005, United States
| | - Savannah C. Wakita
- School of Mathematical and
Physical Sciences, University of New England, Biddeford, Maine 04005, United States
| | - Jeffery D. V. Waters
- School of Mathematical and
Physical Sciences, University of New England, Biddeford, Maine 04005, United States
| | - Eva Rose M. Balog
- School of Mathematical and
Physical Sciences, University of New England, Biddeford, Maine 04005, United States
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3
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Buenaventura A, Saito T, Kanao T, Matsunaga D, Matsui TS, Deguchi S. Intracellular Macromolecular Crowding within Individual Stress Fibers Analyzed by Fluorescence Correlation Spectroscopy. Cell Mol Bioeng 2024; 17:165-176. [PMID: 39050511 PMCID: PMC11263330 DOI: 10.1007/s12195-024-00803-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Accepted: 05/06/2024] [Indexed: 07/27/2024] Open
Abstract
Introduction The diffusion of cell components such as proteins is crucial to the function of all living cells. The abundance of macromolecules in cells is likely to cause a state of macromolecular crowding, but its effects on the extent of diffusion remain poorly understood. Methods Here we investigate the diffusion rate in three distinct locations in mesenchymal cell types, namely the open cytoplasm, the stress fibers in the open cytoplasm, and those below the nucleus using three kinds of biologically inert green fluorescent proteins (GFPs), namely a monomer, dimer, and trimer GFP. Fluorescence correlation spectroscopy (FCS) was used to determine the diffusion coefficients. Results We show that diffusion tends to be lowered on average in stress fibers and is significantly lower in those located below the nucleus. Our data suggest that the diffusive properties of GFPs, and potentially other molecules as well, are hindered by macromolecular crowding. However, although the size dependence on protein diffusion was also studied for monomer, dimer, and trimer GFPs, there was no significant difference in the diffusion rates among the GFPs of these sizes. These results could be attributed to the lack of significant change in protein size among the selected GFP multimers. Conclusion The data presented here would provide a basis for better understanding of the complex protein diffusion in the nonuniform cytoplasm, shedding light on cellular responses to mechanical stress, their local mechanical properties, and reduced turnover in senescent cells.
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Affiliation(s)
- Aria Buenaventura
- Division of Bioengineering, Osaka University, Toyonaka, 560-0043 Japan
| | - Takumi Saito
- Division of Bioengineering, Osaka University, Toyonaka, 560-0043 Japan
- Graduate School of Biomedical Engineering, Tohoku University, Sendai, 980-0812 Japan
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, USA
- Nanobiology Institute, Yale University, West Haven, USA
| | - Taiga Kanao
- Division of Bioengineering, Osaka University, Toyonaka, 560-0043 Japan
| | - Daiki Matsunaga
- Division of Bioengineering, Osaka University, Toyonaka, 560-0043 Japan
| | - Tsubasa S. Matsui
- Division of Bioengineering, Osaka University, Toyonaka, 560-0043 Japan
| | - Shinji Deguchi
- Division of Bioengineering, Osaka University, Toyonaka, 560-0043 Japan
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4
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Hedtfeld M, Dammers A, Koerner C, Musacchio A. A validation strategy to assess the role of phase separation as a determinant of macromolecular localization. Mol Cell 2024; 84:1783-1801.e7. [PMID: 38614097 DOI: 10.1016/j.molcel.2024.03.022] [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: 06/04/2023] [Revised: 12/11/2023] [Accepted: 03/22/2024] [Indexed: 04/15/2024]
Abstract
Liquid-liquid phase separation (LLPS) of putative assembly scaffolds has been proposed to drive the biogenesis of membraneless compartments. LLPS scaffolds are usually identified through in vitro LLPS assays with single macromolecules (homotypic), but the predictive value of these assays remains poorly characterized. Here, we apply a strategy to evaluate the robustness of homotypic LLPS assays. When applied to the chromosomal passenger complex (CPC), which undergoes LLPS in vitro and localizes to centromeres to promote chromosome biorientation, LLPS propensity in vitro emerged as an unreliable predictor of subcellular localization. In vitro CPC LLPS in aqueous buffers was enhanced by commonly used crowding agents. Conversely, diluted cytomimetic media dissolved condensates of the CPC and of several other proteins. We also show that centromeres do not seem to nucleate LLPS, nor do they promote local, spatially restrained LLPS of the CPC. Our strategy can be adapted to purported LLPS scaffolds of other membraneless compartments.
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Affiliation(s)
- Marius Hedtfeld
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Straße 11, 44227 Dortmund, Germany; Centre for Medical Biotechnology, Faculty of Biology, University Duisburg-Essen, Essen, Germany
| | - Alicia Dammers
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Straße 11, 44227 Dortmund, Germany
| | - Carolin Koerner
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Straße 11, 44227 Dortmund, Germany
| | - Andrea Musacchio
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Otto-Hahn-Straße 11, 44227 Dortmund, Germany; Centre for Medical Biotechnology, Faculty of Biology, University Duisburg-Essen, Essen, Germany.
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5
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Xu G, Cheng K, Liu M, Li C. Studying protein stability in crowded environments by NMR. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2024; 140-141:42-48. [PMID: 38705635 DOI: 10.1016/j.pnmrs.2024.01.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2023] [Revised: 01/30/2024] [Accepted: 01/31/2024] [Indexed: 05/07/2024]
Abstract
Most proteins perform their functions in crowded and complex cellular environments where weak interactions are ubiquitous between biomolecules. These complex environments can modulate the protein folding energy landscape and hence affect protein stability. NMR is a nondestructive and effective method to quantify the kinetics and equilibrium thermodynamic stability of proteins at an atomic level within crowded environments and living cells. Here, we review NMR methods that can be used to measure protein stability, as well as findings of studies on protein stability in crowded environments mimicked by polymer and protein crowders and in living cells. The important effects of chemical interactions on protein stability are highlighted and compared to spatial excluded volume effects.
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Affiliation(s)
- Guohua Xu
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan National Laboratory for Optoelectronics, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, PR China
| | - Kai Cheng
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan National Laboratory for Optoelectronics, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, PR China
| | - Maili Liu
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan National Laboratory for Optoelectronics, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, PR China
| | - Conggang Li
- Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan National Laboratory for Optoelectronics, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, PR China.
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6
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Alfano C, Fichou Y, Huber K, Weiss M, Spruijt E, Ebbinghaus S, De Luca G, Morando MA, Vetri V, Temussi PA, Pastore A. Molecular Crowding: The History and Development of a Scientific Paradigm. Chem Rev 2024; 124:3186-3219. [PMID: 38466779 PMCID: PMC10979406 DOI: 10.1021/acs.chemrev.3c00615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 02/13/2024] [Accepted: 02/26/2024] [Indexed: 03/13/2024]
Abstract
It is now generally accepted that macromolecules do not act in isolation but "live" in a crowded environment, that is, an environment populated by numerous different molecules. The field of molecular crowding has its origins in the far 80s but became accepted only by the end of the 90s. In the present issue, we discuss various aspects that are influenced by crowding and need to consider its effects. This Review is meant as an introduction to the theme and an analysis of the evolution of the crowding concept through time from colloidal and polymer physics to a more biological perspective. We introduce themes that will be more thoroughly treated in other Reviews of the present issue. In our intentions, each Review may stand by itself, but the complete collection has the aspiration to provide different but complementary perspectives to propose a more holistic view of molecular crowding.
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Affiliation(s)
- Caterina Alfano
- Structural
Biology and Biophysics Unit, Fondazione
Ri.MED, 90100 Palermo, Italy
| | - Yann Fichou
- CNRS,
Bordeaux INP, CBMN UMR 5248, IECB, University
of Bordeaux, F-33600 Pessac, France
| | - Klaus Huber
- Department
of Chemistry, University of Paderborn, 33098 Paderborn, Germany
| | - Matthias Weiss
- Experimental
Physics I, Physics of Living Matter, University
of Bayreuth, 95440 Bayreuth, Germany
| | - Evan Spruijt
- Institute
for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - Simon Ebbinghaus
- Lehrstuhl
für Biophysikalische Chemie and Research Center Chemical Sciences
and Sustainability, Research Alliance Ruhr, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - Giuseppe De Luca
- Dipartimento
di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche, Università degli Studi di Palermo, Viale delle Scienze, 90128 Palermo, Italy
| | | | - Valeria Vetri
- Dipartimento
di Fisica e Chimica − Emilio Segrè, Università degli Studi di Palermo, Viale delle Scienze, 90128 Palermo, Italy
| | | | - Annalisa Pastore
- King’s
College London, Denmark
Hill Campus, SE5 9RT London, United Kingdom
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7
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Ben‐Ishay Y, Barak Y, Feintuch A, Ouari O, Pierro A, Mileo E, Su X, Goldfarb D. Exploring the dynamics and structure of PpiB in living Escherichia coli cells using electron paramagnetic resonance spectroscopy. Protein Sci 2024; 33:e4903. [PMID: 38358137 PMCID: PMC10868451 DOI: 10.1002/pro.4903] [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: 11/14/2023] [Revised: 12/29/2023] [Accepted: 01/04/2024] [Indexed: 02/16/2024]
Abstract
The combined effects of the cellular environment on proteins led to the definition of a fifth level of protein structural organization termed quinary structure. To explore the implication of potential quinary structure for globular proteins, we studied the dynamics and conformations of Escherichia coli (E. coli) peptidyl-prolyl cis/trans isomerase B (PpiB) in E. coli cells. PpiB plays a major role in maturation and regulation of folded proteins by catalyzing the cis/trans isomerization of the proline imidic peptide bond. We applied electron paramagnetic resonance (EPR) techniques, utilizing both Gadolinium (Gd(III)) and nitroxide spin labels. In addition to using standard spin labeling approaches with genetically engineered cysteines, we incorporated an unnatural amino acid to achieve Gd(III)-nitroxide orthogonal labeling. We probed PpiB's residue-specific dynamics by X-band continuous wave EPR at ambient temperatures and its structure by double electron-electron resonance (DEER) on frozen samples. PpiB was delivered to E. coli cells by electroporation. We report a significant decrease in the dynamics induced by the cellular environment for two chosen labeling positions. These changes could not be reproduced by adding crowding agents and cell extracts. Concomitantly, we report a broadening of the distance distribution in E. coli, determined by Gd(III)-Gd(III) DEER measurements, as compared with solution and human HeLa cells. This suggests an increase in the number of PpiB conformations present in E. coli cells, possibly due to interactions with other cell components, which also contributes to the reduction in mobility and suggests the presence of a quinary structure.
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Affiliation(s)
- Yasmin Ben‐Ishay
- Department of Chemical and Biological PhysicsWeizmann Institute of ScienceRehovotIsrael
| | - Yoav Barak
- Department of Chemical Research SupportWeizmann Institute of ScienceRehovotIsrael
| | - Akiva Feintuch
- Department of Chemical and Biological PhysicsWeizmann Institute of ScienceRehovotIsrael
| | - Olivier Ouari
- CNRS, ICR, Institut de Chimie RadicalaireAix‐Marseille UniversitéMarseilleFrance
| | - Annalisa Pierro
- CNRS, BIP, Laboratoire de Bioénergétique et Ingénierie des ProtéinesAix Marseille UniversitéMarseilleFrance
- Present address:
Konstanz Research School Chemical Biology, Department of ChemistryUniversity of KonstanzKonstanzGermany
| | - Elisabetta Mileo
- CNRS, BIP, Laboratoire de Bioénergétique et Ingénierie des ProtéinesAix Marseille UniversitéMarseilleFrance
| | - Xun‐Cheng Su
- State Key Laboratory of Elemento‐organic Chemistry, Tianjin Key Laboratory of Biosensing and Molecular RecognitionCollege of Chemistry, Nankai UniversityTianjinChina
| | - Daniella Goldfarb
- Department of Chemical and Biological PhysicsWeizmann Institute of ScienceRehovotIsrael
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8
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Monterroso B, Margolin W, Boersma AJ, Rivas G, Poolman B, Zorrilla S. Macromolecular Crowding, Phase Separation, and Homeostasis in the Orchestration of Bacterial Cellular Functions. Chem Rev 2024; 124:1899-1949. [PMID: 38331392 PMCID: PMC10906006 DOI: 10.1021/acs.chemrev.3c00622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 12/01/2023] [Accepted: 01/10/2024] [Indexed: 02/10/2024]
Abstract
Macromolecular crowding affects the activity of proteins and functional macromolecular complexes in all cells, including bacteria. Crowding, together with physicochemical parameters such as pH, ionic strength, and the energy status, influences the structure of the cytoplasm and thereby indirectly macromolecular function. Notably, crowding also promotes the formation of biomolecular condensates by phase separation, initially identified in eukaryotic cells but more recently discovered to play key functions in bacteria. Bacterial cells require a variety of mechanisms to maintain physicochemical homeostasis, in particular in environments with fluctuating conditions, and the formation of biomolecular condensates is emerging as one such mechanism. In this work, we connect physicochemical homeostasis and macromolecular crowding with the formation and function of biomolecular condensates in the bacterial cell and compare the supramolecular structures found in bacteria with those of eukaryotic cells. We focus on the effects of crowding and phase separation on the control of bacterial chromosome replication, segregation, and cell division, and we discuss the contribution of biomolecular condensates to bacterial cell fitness and adaptation to environmental stress.
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Affiliation(s)
- Begoña Monterroso
- Department
of Structural and Chemical Biology, Centro de Investigaciones Biológicas
Margarita Salas, Consejo Superior de Investigaciones
Científicas (CSIC), 28040 Madrid, Spain
| | - William Margolin
- Department
of Microbiology and Molecular Genetics, McGovern Medical School, UTHealth-Houston, Houston, Texas 77030, United States
| | - Arnold J. Boersma
- Cellular
Protein Chemistry, Bijvoet Centre for Biomolecular Research, Faculty
of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Germán Rivas
- Department
of Structural and Chemical Biology, Centro de Investigaciones Biológicas
Margarita Salas, Consejo Superior de Investigaciones
Científicas (CSIC), 28040 Madrid, Spain
| | - Bert Poolman
- Department
of Biochemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Silvia Zorrilla
- Department
of Structural and Chemical Biology, Centro de Investigaciones Biológicas
Margarita Salas, Consejo Superior de Investigaciones
Científicas (CSIC), 28040 Madrid, Spain
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9
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Ota C, Konishi T, Tanaka SI, Takano K. Induced Circular Dichroism Analysis of Thermally Induced Conformational Changes on Protein Binding Sites Under a Crowding Environment. Chemphyschem 2024; 25:e202300593. [PMID: 37845184 DOI: 10.1002/cphc.202300593] [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: 08/20/2023] [Revised: 10/15/2023] [Accepted: 10/16/2023] [Indexed: 10/18/2023]
Abstract
Protein-ligand interactions in crowded cellular environments play a crucial role in biological functions. The crowded environment can perturb the overall protein structure and local conformation, thereby influencing the binding pathway of protein-ligand reactions within the cellular milieu. Therefore, a detailed understanding of the local conformation is crucial for elucidating the intricacies of protein-ligand interactions in crowded cellular environments. In this study, we investigated the feasibility of induced circular dichroism (ICD) using 8-anilinonaphthalene-1-sulfonic acid (ANS) for local conformational analysis at the binding site in a crowding environment. Bovine serum albumin (BSA) concentration-dependent measurements were performed to assess the feasibility of ANS-ICD for analyzing protein interior binding sites. The results showed distinct changes in the ANS-ICD spectra of BSA solutions, indicating their potential for analyzing the internal conformation of proteins. Moreover, temperature-dependent measurements were performed in dilute and crowding environments, revealing distinct denaturation pathways of BSA binding sites. Principal component analysis of ANS-ICD spectral changes revealed lower temperature pre-denaturation in the crowded solution than that in the diluted solution, suggesting destabilization of binding sites owing to self-crowding repulsive interactions. The established ANS-ICD method can provide valuable conformational insights into protein-ligand interactions in crowded cellular environments.
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Affiliation(s)
- Chikashi Ota
- College of Life Sciences, Ritsumeikan University, Kusatsu, Shiga, 525-8577, Japan
| | - Tomoya Konishi
- Department of Biomolecular Chemistry, Kyoto Prefectural University, Sakyo-ku, Kyoto, 606-8522, Japan
| | - Shun-Ichi Tanaka
- Department of Biomolecular Chemistry, Kyoto Prefectural University, Sakyo-ku, Kyoto, 606-8522, Japan
| | - Kazufumi Takano
- Department of Biomolecular Chemistry, Kyoto Prefectural University, Sakyo-ku, Kyoto, 606-8522, Japan
- Kazufumi Takano - Department of Biomolecular Chemistry, Kyoto Prefectural University, Sakyo-ku, Kyoto, 606-8522, Japan
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10
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Peters J, Oliva R, Caliò A, Oger P, Winter R. Effects of Crowding and Cosolutes on Biomolecular Function at Extreme Environmental Conditions. Chem Rev 2023; 123:13441-13488. [PMID: 37943516 DOI: 10.1021/acs.chemrev.3c00432] [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: 11/10/2023]
Abstract
The extent of the effect of cellular crowding and cosolutes on the functioning of proteins and cells is manifold and includes the stabilization of the biomolecular systems, the excluded volume effect, and the modulation of molecular dynamics. Simultaneously, it is becoming increasingly clear how important it is to take the environment into account if we are to shed light on biological function under various external conditions. Many biosystems thrive under extreme conditions, including the deep sea and subseafloor crust, and can take advantage of some of the effects of crowding. These relationships have been studied in recent years using various biophysical techniques, including neutron and X-ray scattering, calorimetry, FTIR, UV-vis and fluorescence spectroscopies. Combining knowledge of the structure and conformational dynamics of biomolecules under extreme conditions, such as temperature, high hydrostatic pressure, and high salinity, we highlight the importance of considering all results in the context of the environment. Here we discuss crowding and cosolute effects on proteins, nucleic acids, membranes, and live cells and explain how it is possible to experimentally separate crowding-induced effects from other influences. Such findings will contribute to a better understanding of the homeoviscous adaptation of organisms and the limits of life in general.
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Affiliation(s)
- Judith Peters
- Univ. Grenoble Alpes, CNRS, LiPhy, 140 rue de la physique, 38400 St Martin d'Hères, France
- Institut Laue Langevin, 71 avenue des Martyrs, 38000 Grenoble, France
- Institut Universitaire de France, 75005 Paris, France
| | - Rosario Oliva
- Department of Chemical Sciences, University of Naples Federico II, Via Cintia 4, 80126 Naples, Italy
| | - Antonino Caliò
- European Synchrotron Radiation Facility, 71 avenue des Martyrs, 38000 Grenoble, France
| | - Philippe Oger
- INSA Lyon, Universite Claude Bernard Lyon1, CNRS, UMR5240, 69621 Villeurbanne, France
| | - Roland Winter
- Department of Chemistry and Chemical Biology, Biophysical Chemistry, TU Dortmund University, Dortmund, Otto-Hahn-Str. 4a, D-44227 Dortmund, Germany
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11
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Löwe M, Hänsch S, Hachani E, Schmitt L, Weidtkamp-Peters S, Kedrov A. Probing macromolecular crowding at the lipid membrane interface with genetically-encoded sensors. Protein Sci 2023; 32:e4797. [PMID: 37779215 PMCID: PMC10578116 DOI: 10.1002/pro.4797] [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: 05/01/2023] [Revised: 08/25/2023] [Accepted: 09/28/2023] [Indexed: 10/03/2023]
Abstract
Biochemical processes within the living cell occur in a highly crowded environment, where macromolecules, first of all proteins and nucleic acids, occupy up to 30% of the volume. The phenomenon of macromolecular crowding is not an exclusive feature of the cytoplasm and can be observed in the densely protein-packed, nonhomogeneous cellular membranes and at the membrane interfaces. Crowding affects diffusional and conformational dynamics of proteins within the lipid bilayer, alters kinetic and thermodynamic properties of biochemical reactions, and modulates the membrane organization. Despite its importance, the non-invasive quantification of the membrane crowding is not trivial. Here, we developed a genetically-encoded fluorescence-based sensor for probing the macromolecular crowding at the membrane interfaces. Two sensor variants, both composed of fluorescent proteins and a membrane anchor, but differing by flexible linker domains were characterized in vitro, and the procedures for the membrane reconstitution were established. Steric pressure induced by membrane-tethered synthetic and protein crowders altered the sensors' conformation, causing increase in the intramolecular Förster's resonance energy transfer. Notably, the effect of protein crowders only weakly correlated with their molecular weight, suggesting that other factors, such as shape and charge contribute to the crowding via the quinary interactions. Finally, measurements performed in inner membrane vesicles of Escherichia coli validated the crowding-dependent dynamics of the sensors in the physiologically relevant environment. The sensors offer broad opportunities to study interfacial crowding in a complex environment of native membranes, and thus add to the toolbox of methods for studying membrane dynamics and proteostasis.
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Affiliation(s)
- Maryna Löwe
- Synthetic Membrane Systems, Institute of Biochemistry, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Sebastian Hänsch
- Center for Advanced imaging, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Eymen Hachani
- Institute of Biochemistry, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Lutz Schmitt
- Institute of Biochemistry, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | | | - Alexej Kedrov
- Synthetic Membrane Systems, Institute of Biochemistry, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
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12
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Lewis BA, Das SK, Jha RK, Levens D. Self-assembly of promoter DNA and RNA Pol II machinery into transcriptionally active biomolecular condensates. SCIENCE ADVANCES 2023; 9:eadi4565. [PMID: 37851801 PMCID: PMC10584347 DOI: 10.1126/sciadv.adi4565] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 09/13/2023] [Indexed: 10/20/2023]
Abstract
Transcription in the nucleus occurs in a concentrated, dense environment, and no reasonable biochemical facsimile of this milieu exists. Such a biochemical environment would be important for further understanding transcriptional regulation. We describe here the formation of dense, transcriptionally active bodies in vitro with only nuclear extracts and promoter DNA. These biomolecular condensates (BMCs) are 0.5 to 1 μm in diameter, have a macromolecular density of approximately 100 mg/ml, and are a consequence of a phase transition between promoter DNA and nuclear extract proteins. BMCs are physically associated with transcription as any disruption of one compromised the other. The BMCs contain RNA polymerase II and elongation factors, as well as factors necessary for BMC formation in vivo. We suggest that BMCs are representative of the in vivo nuclear environment and a more physiologically relevant manifestation of the preinitiation complex/elongation machinery.
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Affiliation(s)
- Brian A. Lewis
- Gene Regulation Section, LP/CCR/NCI/NIH, 9000 Rockville Pike, Bethesda, MD 20892, USA
| | - Subhendu Kumar Das
- Gene Regulation Section, LP/CCR/NCI/NIH, 9000 Rockville Pike, Bethesda, MD 20892, USA
| | - Rajiv Kumar Jha
- Gene Regulation Section, LP/CCR/NCI/NIH, 9000 Rockville Pike, Bethesda, MD 20892, USA
| | - David Levens
- Gene Regulation Section, LP/CCR/NCI/NIH, 9000 Rockville Pike, Bethesda, MD 20892, USA
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13
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Mathur N, Singh N. Melting of dsDNA attached with AuNPs. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2023; 46:58. [PMID: 37477744 DOI: 10.1140/epje/s10189-023-00318-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Accepted: 07/05/2023] [Indexed: 07/22/2023]
Abstract
DNA-linked gold nanoparticles (DNA-AuNPs) are combined nanomaterials that contain the optical and electronic properties of AuNPs with the unique functions of DNA. These hybrid systems are used in various nanobiotechnology, medical, and pharmaceutical sciences (Löwe et al. in FEBS J 287(23):5039, 2020; Speer et al. in Annu Rev Biophys 51:267, 2022). In recent years, there has been an increasing interest in studying the behavior of DNA-AuNPs in the presence of molecular solvents. In the present work, we study the thermal melting of DNA-linked gold nanoparticles (DNA-AuNP). In the first part of the study, we find the melting profile of short heterogeneous DNA-linked AuNP in the presence of solvent in the solution. We also study the effect of the location of the gold nanoparticle attached to the DNA molecule. In this case, we move the location of the AuNP from one end to the other. We found that while the melting temperature is susceptible to the location of the AuNP when it is near the ends, there is a region in the middle section of the chain where the melting temperature remains constant.
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Affiliation(s)
- Neha Mathur
- BITS-Pilani, Pilani Campus, 333031, Pilani, India.
| | - Navin Singh
- BITS-Pilani, Pilani Campus, 333031, Pilani, India
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14
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Rivas G. Biophysical Reviews' "Meet the Editors Series"-a profile of Germán Rivas. Biophys Rev 2023; 15:151-156. [PMID: 37124917 PMCID: PMC10133429 DOI: 10.1007/s12551-023-01061-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/23/2023] [Indexed: 05/02/2023] Open
Abstract
German Rivas is an executive editor of the IUPAB Biophysical Reviews journal based in Spain. As the head of the Department of Structural and Chemical Biology at the Center for Biological Research (CIB) Margarita Salas (one of the largest research institutes devoted to life sciences of the Spanish National Research Council (CSIC)), he leads a research program aimed at understanding the structure function relationship of large macromolecular complexes (involved in bacterial cell division) when placed in physiologically complex and "crowded" media toward their reconstitution from the bottom up in cell-like compartments. In this "Meet the Editors'" piece, he briefly describes his research interests and history.
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Affiliation(s)
- Germán Rivas
- Systems Biochemistry Lab, Department of Structural and Chemical Biology, CIB Margarita Salas – CSIC, 28040 Madrid, Spain
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15
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Irukuvajjula SS, Jithender Reddy G, Rao K, Vadrevu LR. Contrasting effect of ficoll on apo and holo forms of bacterial chemotaxis protein Y: Selective destabilization of the conformationally altered holo form. Int J Biol Macromol 2023; 232:123505. [PMID: 36736516 DOI: 10.1016/j.ijbiomac.2023.123505] [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: 11/03/2022] [Revised: 01/13/2023] [Accepted: 01/28/2023] [Indexed: 02/04/2023]
Abstract
Chemotaxis Y (CheY), upon metal binding, displays a drastic alteration in its structure and stability. This premise prompted us to study the effect of crowding on the two conformationally distinct states of the same test protein. A comparative analysis on the structure and thermal stability in the presence and absence of the macromolecular crowder, ficoll, and its monomeric unit, sucrose, revealed a contrasting effect of ficoll on the apo and holo forms. In the presence of ficoll while the thermal stability (Tm) of the apo form is enhanced, the thermal stability of the holo form is reduced. The selective lowering of Tm for the holo form in the combined presence of ficoll and sucrose and not in sucrose alone suggests that the contrasting effect is due to the macromolecular nature of ficoll. Since metal-protein interaction remains unperturbed in the presence of ficoll and Mg2+ sequestration is ruled out in a systematic manner the alternative possibility for the exclusive reduction in the thermal stability of the holo form is the ficoll-induced modulation of the relative population of apo and holo forms of CheY.
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Affiliation(s)
- Shivkumar Sharma Irukuvajjula
- Department of Biological Sciences, Birla Institute of Science and Technology - Pilani, Hyderabad Campus, Shamirpet, Hyderabad 500078, India.
| | - G Jithender Reddy
- NMR Division, Department of Analytical & Structural Chemistry, CSIR-Indian Institute of Chemical Technology, Ministry of Science and Technology, Uppal Road, Tarnaka, Hyderabad 500007, India
| | - Krishna Rao
- Tata Institute of Fundamental Research, 36/P, Gopanpally Mandal, Ranga Reddy District, Hyderabad, Telangana State 500107, India
| | - Late Ramakrishna Vadrevu
- Department of Biological Sciences, Birla Institute of Science and Technology - Pilani, Hyderabad Campus, Shamirpet, Hyderabad 500078, India
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16
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Pradhan S, Rath R, Biswas M. GB1 Dimerization in Crowders: A Multiple Resolution Approach. J Chem Inf Model 2023; 63:1570-1577. [PMID: 36858485 DOI: 10.1021/acs.jcim.3c00012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/03/2023]
Abstract
In-cell protein-protein association, which is crucial in enzyme catalysis and polymerization, occurs in an environment that is highly heterogeneous and crowded. The crowder molecules exclude the reactant molecules from occupying certain regions of the cell, resulting in changes in the reaction thermodynamics and kinetics. Recent studies, both experiment and simulations, revealed that the nature of the interaction between crowder and protein species, in particular the soft interactions, plays an important role in crowder induced effects on protein association. To this end, from a simulation perspective, it is important to decipher the level of structural resolution in a protein-crowder model that can faithfully capture the influence of crowding on protein association. Here, we investigate the dimerization of model system GB1 in the presence of lysozyme crowders at two structural resolutions. The lower resolution model assumes both protein and crowder species as spherical beads, similar to the analytical scaled particle theory model, whereas the higher resolution model retains residue specific structural details for protein and crowder species. From the higher resolution model, it is found that GB1 dimer formation is destabilized in the presence of lysozyme crowders, and the destabilization is more for the side-by-side dimer compared to the domain-swapped dimer, in qualitative agreement with experimental findings. However, the low resolution CG model predicts stabilization of the dimers in the presence of the lysozyme crowder, similar to the SPT model. Our results indicate a nontrivial role of the choice of model resolution in computer simulation studies investigating crowder induced effects.
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Affiliation(s)
- Sweta Pradhan
- National Institute of Technology Rourkela, Rourkela 769008, India
| | - Rajendra Rath
- National Institute of Technology Rourkela, Rourkela 769008, India
| | - Mithun Biswas
- National Institute of Technology Rourkela, Rourkela 769008, India
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17
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André AAM, Yewdall NA, Spruijt E. Crowding-induced phase separation and gelling by co-condensation of PEG in NPM1-rRNA condensates. Biophys J 2023; 122:397-407. [PMID: 36463407 PMCID: PMC9892608 DOI: 10.1016/j.bpj.2022.12.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 11/11/2022] [Accepted: 11/30/2022] [Indexed: 12/12/2022] Open
Abstract
The crowdedness of the cell calls for adequate intracellular organization. Biomolecular condensates, formed by liquid-liquid phase separation of intrinsically disordered proteins and nucleic acids, are important organizers of cellular fluids. To underpin the molecular mechanisms of protein condensation, cell-free studies are often used where the role of crowding is not investigated in detail. Here, we investigate the effects of macromolecular crowding on the formation and material properties of a model heterotypic biomolecular condensate, consisting of nucleophosmin (NPM1) and ribosomal RNA (rRNA). We studied the effect of the macromolecular crowding agent poly(ethylene glycol) (PEG), which is often considered an inert crowding agent. We observed that PEG could induce both homotypic and heterotypic phase separation of NPM1 and NPM1-rRNA, respectively. Crowding increases the condensed concentration of NPM1 and decreases its equilibrium dilute phase concentration, although no significant change in the concentration of rRNA in the dilute phase was observed. Interestingly, the crowder itself is concentrated in the condensates, suggesting that co-condensation rather than excluded volume interactions underlie the enhanced phase separation by PEG. Fluorescence recovery after photobleaching measurements indicated that both NPM1 and rRNA become immobile at high PEG concentrations, indicative of a liquid-to-gel transition. Together, these results provide more insight into the role of synthetic crowding agents in phase separation and demonstrate that condensate properties determined in vitro depend strongly on the addition of crowding agents.
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Affiliation(s)
- Alain A M André
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, the Netherlands
| | - N Amy Yewdall
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, the Netherlands
| | - Evan Spruijt
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, the Netherlands.
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18
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Xie Y, Gresham D, Holt L. Increased mesoscale diffusivity in response to acute glucose starvation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.10.523352. [PMID: 36711511 PMCID: PMC9882054 DOI: 10.1101/2023.01.10.523352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Macromolecular crowding is an important parameter that impacts multiple biological processes. Passive microrheology using single particle tracking is a powerful means of studying macromolecular crowding. Here we monitored the diffusivity of self-assembling fluorescent nanoparticles (μNS) in response to acute glucose starvation. mRNP diffusivity was reduced upon glucose starvation as previously reported. In contrast, we observed increased diffusivity of μNS particles. Our results suggest that, upon glucose starvation, mRNP granule diffusivity may be reduced due to changes in physical interactions, while global crowding in the cytoplasm may be reduced.
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Affiliation(s)
- Ying Xie
- New York University, School of Medicine, Institute for Systems Genetics, New York, USA
- New York University, Center for Genomics and Systems Biology, Department of Biology, New York, USA
| | - David Gresham
- New York University, Center for Genomics and Systems Biology, Department of Biology, New York, USA
| | - Liam Holt
- New York University, School of Medicine, Institute for Systems Genetics, New York, USA
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19
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Xie Y, Gresham D, Holt LJ. Increased mesoscale diffusivity in response to acute glucose starvation. MICROPUBLICATION BIOLOGY 2023; 2023:10.17912/micropub.biology.000729. [PMID: 36908311 PMCID: PMC9996311 DOI: 10.17912/micropub.biology.000729] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 02/16/2023] [Accepted: 02/20/2023] [Indexed: 03/14/2023]
Abstract
Macromolecular crowding is an important property of cells that impacts multiple biological processes. Passive microrheology using single particle tracking is a powerful means of studying macromolecular crowding. Here we monitored the diffusivity of self-assembling fluorescent nanoparticles (μNS) and mRNPs ( GFA1 -PP7) in response to acute glucose starvation. mRNP diffusivity was reduced upon glucose starvation as previously reported. By contrast, we observed increased diffusivity of μNS particles. Our results suggest that, upon glucose starvation, mRNP granule diffusivity may be reduced due to increased physical interactions, whereas macromolecular crowding in the cytoplasm may be globally reduced.
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Affiliation(s)
- Ying Xie
- Institute for Systems Genetics, New York University Langone Medical Center, New York, New York, United States
- Department of Biology, New York University, New York, New York, United States
| | - David Gresham
- Department of Biology, New York University, New York, New York, United States
- Correspondence to: David Gresham (
)
| | - Liam J Holt
- Institute for Systems Genetics, New York University Langone Medical Center, New York, New York, United States
- Correspondence to: Liam J Holt (
)
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20
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Cammarata M, Piazza F, Rivas G, Schirò G, Temussi PA, Pastore A. Revitalizing an important field in biophysics: The new frontiers of molecular crowding. Front Mol Biosci 2023; 10:1153996. [PMID: 36923640 PMCID: PMC10010569 DOI: 10.3389/fmolb.2023.1153996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Accepted: 02/13/2023] [Indexed: 03/02/2023] Open
Abstract
Taking into account the presence of the crowded environment of a macromolecule has been an important goal of biology over the past 20 years. Molecular crowding affects the motions, stability and the kinetic behaviour of proteins. New powerful approaches have recently been developed to study molecular crowding, some of which make use of the synchrotron radiation light. The meeting "New Frontiers in Molecular Crowding" was organized in July 2022at the European Synchrotron Radiation facility of Grenoble to discuss the new frontiers of molecular crowding. The workshop brought together researchers from different disciplines to highlight the new developments of the field, including areas where new techniques allow the scientists to gain unprecedently expected information. A key conclusion of the meeting was the need to build an international and interdisciplinary research community through enhanced communication, resource-sharing, and educational initiatives that could let the molecular crowding field flourish further.
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Affiliation(s)
- Marco Cammarata
- Experiment Division, European Synchrotron Radiation Facility, 71 Ave des Martyrs, Grenoble, France
| | - Francesco Piazza
- Department of Physics & Astronomy, University of Florence and INFN Sezione di Firenze, Sesto Fiorentino, Italy
| | - Germán Rivas
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Giorgio Schirò
- CNRS, CEA, IBS, University Grenoble Alpes, Grenoble, France
| | - Piero Andrea Temussi
- Dipartimento di Scienze Chimiche, University "Federico II" of Naples, via Cynthia, Naples, Italy
| | - Annalisa Pastore
- Experiment Division, European Synchrotron Radiation Facility, 71 Ave des Martyrs, Grenoble, France
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21
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Ota C, Suzuki H, Tanaka SI, Takano K. Dispersion Effect of Molecular Crowding on Ligand-Protein Surface Binding Sites of Escherichia coli RNase HI. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:14497-14507. [PMID: 36379030 DOI: 10.1021/acs.langmuir.2c02625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The molecular crowding effect on ligand-protein interactions, which plays several crucial roles in life processes, has been investigated using various models by adding crowding agents to mimic the intracellular environment. Several studies evaluating this effect have focused on the ligand-protein binding reaction of well-structured binding sites with rigid conformations. However, the crowding effect on flexible binding sites is not well-understood, especially in terms of the conformations. In this work, to elucidate the detailed molecular mechanism underlying the ligand-protein interactions with flexible binding sites on a protein surface, we studied the interaction between the basic protrusion of Escherichia coli ribonuclease HI (RNase HI) and 8-anilinonaphthalene-1-sulfonic acid (ANS). The RNase HI concentration-dependent measurement of ANS fluorescence combined with the multivariate analysis and the fluorescence vibronic structure analysis revealed an increase in the heterogeneous species with an increase in the protein concentration, which is a different behavior from that of proteins with rigid binding sites. This result indicates that ANS molecules bind to the additional binding sites because of the destabilization of the main sites by the excluded volume effect in a crowded environment. The fluorescence vibronic structure analysis yields a detailed molecular picture, indicating that the main species of ANS can have a distorted structure. On the other hand, some ANS molecules move to the minor binding sites of a different microenvironment to secure a stabilized structure. These spectroscopic analyses may show a hypothesis, suggesting that the decrease in the ΔG difference between the main and minor sites due to destabilization of the main binding site could lower the potential barrier between them, inducing the dispersion of binding pathways.
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Affiliation(s)
- Chikashi Ota
- College of Life Sciences, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan
| | - Hikari Suzuki
- Department of Biomolecular Chemistry, Kyoto Prefectural University, Sakyo-ku, Kyoto 606-8522, Japan
| | - Shun-Ichi Tanaka
- Department of Biomolecular Chemistry, Kyoto Prefectural University, Sakyo-ku, Kyoto 606-8522, Japan
| | - Kazufumi Takano
- Department of Biomolecular Chemistry, Kyoto Prefectural University, Sakyo-ku, Kyoto 606-8522, Japan
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22
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Acquasaliente L, Pontarollo G, Radu CM, Peterle D, Artusi I, Pagotto A, Uliana F, Negro A, Simioni P, De Filippis V. Exogenous human α-Synuclein acts in vitro as a mild platelet antiaggregant inhibiting α-thrombin-induced platelet activation. Sci Rep 2022; 12:9880. [PMID: 35701444 PMCID: PMC9198058 DOI: 10.1038/s41598-022-12886-y] [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: 09/14/2021] [Accepted: 05/18/2022] [Indexed: 11/29/2022] Open
Abstract
α-Synuclein (αSyn) is a small disordered protein, highly conserved in vertebrates and involved in the pathogenesis of Parkinson’s disease (PD). Indeed, αSyn amyloid aggregates are present in the brain of patients with PD. Although the pathogenic role of αSyn is widely accepted, the physiological function of this protein remains elusive. Beyond the central nervous system, αSyn is expressed in hematopoietic tissue and blood, where platelets are a major cellular host of αSyn. Platelets play a key role in hemostasis and are potently activated by thrombin (αT) through the cleavage of protease-activated receptors. Furthermore, both αT and αSyn could be found in the same spatial environment, i.e. the platelet membrane, as αT binds to and activates platelets that can release αSyn from α-granules and microvesicles. Here, we investigated the possibility that exogenous αSyn could interfere with platelet activation induced by different agonists in vitro. Data obtained from distinct experimental techniques (i.e. multiple electrode aggregometry, rotational thromboelastometry, immunofluorescence microscopy, surface plasmon resonance, and steady-state fluorescence spectroscopy) on whole blood and platelet-rich plasma indicate that exogenous αSyn has mild platelet antiaggregating properties in vitro, acting as a negative regulator of αT-mediated platelet activation by preferentially inhibiting P-selectin expression on platelet surface. We have also shown that both exogenous and endogenous (i.e. cytoplasmic) αSyn preferentially bind to the outer surface of activated platelets. Starting from these findings, a coherent model of the antiplatelet function of αSyn is proposed.
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Affiliation(s)
- Laura Acquasaliente
- Laboratory of Protein Chemistry and Molecular Hematology, Department of Pharmaceutical and Pharmacological Sciences, School of Medicine, University of Padua, via Marzolo, 5, 35131, Padua, Italy
| | - Giulia Pontarollo
- Laboratory of Protein Chemistry and Molecular Hematology, Department of Pharmaceutical and Pharmacological Sciences, School of Medicine, University of Padua, via Marzolo, 5, 35131, Padua, Italy.,Center for Thrombosis and Hemostasis (CTH) University Medical Center Mainz, Langenbeckstraße 1, 55131, Mainz, Germany
| | - Claudia Maria Radu
- Department of Women's & Children's Health, University of Padua, Padua, Italy.,Thrombotic and Hemorrhagic Diseases Unit, Department of Medicine, University of Padua, via Giustiniani, 2, 35128, Padua, Italy
| | - Daniele Peterle
- Laboratory of Protein Chemistry and Molecular Hematology, Department of Pharmaceutical and Pharmacological Sciences, School of Medicine, University of Padua, via Marzolo, 5, 35131, Padua, Italy.,Department of Chemistry and Chemical Biology, Northeastern University, 360 Huntington Ave. 02115, Boston, MA, USA
| | - Ilaria Artusi
- Laboratory of Protein Chemistry and Molecular Hematology, Department of Pharmaceutical and Pharmacological Sciences, School of Medicine, University of Padua, via Marzolo, 5, 35131, Padua, Italy
| | - Anna Pagotto
- Laboratory of Protein Chemistry and Molecular Hematology, Department of Pharmaceutical and Pharmacological Sciences, School of Medicine, University of Padua, via Marzolo, 5, 35131, Padua, Italy
| | - Federico Uliana
- Laboratory of Protein Chemistry and Molecular Hematology, Department of Pharmaceutical and Pharmacological Sciences, School of Medicine, University of Padua, via Marzolo, 5, 35131, Padua, Italy.,Institute of Molecular Systems Biology, ETH Zurich, 8093, Zurich, Switzerland
| | - Alessandro Negro
- Department of Biomedical Sciences, University of Padua, viale G. Colombo 3, 35100, Padua, Italy.
| | - Paolo Simioni
- Thrombotic and Hemorrhagic Diseases Unit, Department of Medicine, University of Padua, via Giustiniani, 2, 35128, Padua, Italy.
| | - Vincenzo De Filippis
- Laboratory of Protein Chemistry and Molecular Hematology, Department of Pharmaceutical and Pharmacological Sciences, School of Medicine, University of Padua, via Marzolo, 5, 35131, Padua, Italy. .,Biotechnology Center, CRIBI, University of Padua, Padua, Italy.
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23
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Sciolino N, Liu A, Breindel L, Burz DS, Sulchek T, Shekhtman A. Microfluidics delivery of DARPP-32 into HeLa cells maintains viability for in-cell NMR spectroscopy. Commun Biol 2022; 5:451. [PMID: 35551287 PMCID: PMC9098904 DOI: 10.1038/s42003-022-03412-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 04/26/2022] [Indexed: 11/09/2022] Open
Abstract
High-resolution structural studies of proteins and protein complexes in a native eukaryotic environment present a challenge to structural biology. In-cell NMR can characterize atomic resolution structures but requires high concentrations of labeled proteins in intact cells. Most exogenous delivery techniques are limited to specific cell types or are too destructive to preserve cellular physiology. The feasibility of microfluidics transfection or volume exchange for convective transfer, VECT, as a means to deliver labeled target proteins to HeLa cells for in-cell NMR experiments is demonstrated. VECT delivery does not require optimization or impede cell viability; cells are immediately available for long-term eukaryotic in-cell NMR experiments. In-cell NMR-based drug screening using VECT was demonstrated by collecting spectra of the sensor molecule DARPP32, in response to exogenous administration of Forskolin.
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Affiliation(s)
- Nicholas Sciolino
- University at Albany, Department of Chemistry, Albany, NY, 12222, USA
| | - Anna Liu
- Georgia Tech, School of Mechanical Engineering, Atlanta, GA, 30332, USA
| | - Leonard Breindel
- University at Albany, Department of Chemistry, Albany, NY, 12222, USA
| | - David S Burz
- University at Albany, Department of Chemistry, Albany, NY, 12222, USA
| | - Todd Sulchek
- Georgia Tech, School of Mechanical Engineering, Atlanta, GA, 30332, USA
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24
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Yadav K, Sardana D, Shweta H, Clovis NS, Sen S. Molecular Picture of the Effect of Cosolvent Crowding on Ligand Binding and Dispersed Solvation Dynamics in G-Quadruplex DNA. J Phys Chem B 2022; 126:1668-1681. [PMID: 35170968 DOI: 10.1021/acs.jpcb.1c09349] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Understanding molecular interactions and dynamics of proteins and DNA in a cell-like crowded environment is crucial for predicting their functions within the cell. Noncanonical G-quadruplex DNA (GqDNA) structures adopt various topologies that were shown to be strongly affected by molecular crowding. However, it is unknown how such crowding affects the solvation dynamics in GqDNA. Here, we study the effect of cosolvent (acetonitrile) crowding on ligand (DAPI) solvation dynamics within human telomeric antiparallel GqDNA through direct comparison of time-resolved fluorescence Stokes shift (TRFSS) experiments and molecular dynamics (MD) simulations results. We show that ligand binding affinity to GqDNA is drastically affected by acetonitrile (ACN). Solvation dynamics probed by DAPI in GqDNA groove show dispersed dynamics from ∼100 fs to 10 ns in the absence and presence of 20% and 40% (v/v) ACN. The nature of dynamics remain similar in buffer and 20% ACN, although in 40% ACN, distinct dynamics is observed in <100 ps. MD simulations performed on GqDNA/DAPI complex reveal preferential solvation of ligand by ACN, particularly in 40% ACN. Simulated solvation time-correlation functions calculated from MD trajectories compare very well to the overall solvation dynamics of DAPI in GqDNA, observed in experiments. Linear response decomposition of simulated solvation correlation functions unfolds the origin of dispersed dynamics, showing that the slower dynamics is dominated by DNA-motion in the presence of ACN (and also by the ACN dynamics at higher concentration). However, water-DNA coupled motion controls the slow dynamics in the absence of ACN. Our data, thus, unravel a detailed molecular picture showing that though ACN crowding affect ligand binding affinity to GqDNA significantly, the overall dispersed solvation dynamics in GqDNA remain similar in the absence and the presence of 20% ACN, albeit with a small effect on the dynamics in the presence of 40% ACN due to preferential solvation of ligand by ACN.
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Affiliation(s)
- Kavita Yadav
- Spectroscopy Laboratory, School of Physical Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Deepika Sardana
- Spectroscopy Laboratory, School of Physical Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Him Shweta
- Spectroscopy Laboratory, School of Physical Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Ndege Simisi Clovis
- Spectroscopy Laboratory, School of Physical Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Sobhan Sen
- Spectroscopy Laboratory, School of Physical Sciences, Jawaharlal Nehru University, New Delhi 110067, India
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25
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Rivas G, Minton A. Influence of Nonspecific Interactions on Protein Associations: Implications for Biochemistry In Vivo. Annu Rev Biochem 2022; 91:321-351. [PMID: 35287477 DOI: 10.1146/annurev-biochem-040320-104151] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The cellular interior is composed of a variety of microenvironments defined by distinct local compositions and composition-dependent intermolecular interactions. We review the various types of nonspecific interactions between proteins and between proteins and other macromolecules and supramolecular structures that influence the state of association and functional properties of a given protein existing within a particular microenvironment at a particular point in time. The present state of knowledge is summarized, and suggestions for fruitful directions of research are offered. Expected final online publication date for the Annual Review of Biochemistry, Volume 91 is June 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Germán Rivas
- Department of Structural and Chemical Biology, Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas, Madrid, Spain;
| | - Allen Minton
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA;
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Speer SL, Stewart CJ, Sapir L, Harries D, Pielak GJ. Macromolecular Crowding Is More than Hard-Core Repulsions. Annu Rev Biophys 2022; 51:267-300. [PMID: 35239418 DOI: 10.1146/annurev-biophys-091321-071829] [Citation(s) in RCA: 45] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cells are crowded, but proteins are almost always studied in dilute aqueous buffer. We review the experimental evidence that crowding affects the equilibrium thermodynamics of protein stability and protein association and discuss the theories employed to explain these observations. In doing so, we highlight differences between synthetic polymers and biologically relevant crowders. Theories based on hard-core interactions predict only crowding-induced entropic stabilization. However, experiment-based efforts conducted under physiologically relevant conditions show that crowding can destabilize proteins and their complexes. Furthermore, quantification of the temperature dependence of crowding effects produced by both large and small cosolutes, including osmolytes, sugars, synthetic polymers, and proteins, reveals enthalpic effects that stabilize or destabilize proteins. Crowding-induced destabilization and the enthalpic component point to the role of chemical interactions between and among the macromolecules, cosolutes, and water. We conclude with suggestions for future studies. Expected final online publication date for the Annual Review of Biophysics, Volume 51 is May 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Shannon L Speer
- Department of Chemistry, University of North Carolina at Chapel Hill, North Carolina, USA;
| | - Claire J Stewart
- Department of Chemistry, University of North Carolina at Chapel Hill, North Carolina, USA;
| | - Liel Sapir
- Thomas Lord Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina, USA
| | - Daniel Harries
- Institute of Chemistry and The Fritz Haber Research Center, The Hebrew University, Jerusalem, Israel
| | - Gary J Pielak
- Department of Chemistry, University of North Carolina at Chapel Hill, North Carolina, USA; .,Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, North Carolina, USA.,Lineberger Cancer Research Center, University of North Carolina at Chapel Hill, North Carolina, USA
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27
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Musacchio A. On the role of phase separation in the biogenesis of membraneless compartments. EMBO J 2022; 41:e109952. [PMID: 35107832 PMCID: PMC8886532 DOI: 10.15252/embj.2021109952] [Citation(s) in RCA: 99] [Impact Index Per Article: 49.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 01/07/2022] [Accepted: 01/10/2022] [Indexed: 12/16/2022] Open
Abstract
Molecular mechanistic biology has ushered us into the world of life’s building blocks, revealing their interactions in macromolecular complexes and inspiring strategies for detailed functional interrogations. The biogenesis of membraneless cellular compartments, functional mesoscale subcellular locales devoid of strong internal order and delimiting membranes, is among mechanistic biology’s most demanding current challenges. A developing paradigm, biomolecular phase separation, emphasizes solvation of the building blocks through low‐affinity, weakly adhesive unspecific interactions as the driver of biogenesis of membraneless compartments. Here, I discuss the molecular underpinnings of the phase separation paradigm and demonstrate that validating its assumptions is much more challenging than hitherto appreciated. I also discuss that highly specific interactions, rather than unspecific ones, appear to be the main driver of biogenesis of subcellular compartments, while phase separation may be harnessed locally in selected instances to generate material properties tailored for specific functions, as exemplified by nucleocytoplasmic transport.
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Affiliation(s)
- Andrea Musacchio
- Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Dortmund, Germany
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28
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Gupta M, Chowdhury PK. Protein dynamics as a sensor for macromolecular crowding: Insights into mixed crowding. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2021.117969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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29
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The mechanism of thermal aggregation of glutamate dehydrogenase. The effect of chemical chaperones. Biochimie 2022; 195:27-38. [PMID: 35041856 DOI: 10.1016/j.biochi.2022.01.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 01/11/2022] [Accepted: 01/12/2022] [Indexed: 11/20/2022]
Abstract
Chemical chaperones are low-molecular compounds counteracting protein aggregation. Understanding of the mechanism of their effects is key to their potential use in biotechnology. The aggregation of bovine liver glutamate dehydrogenase (GDH) was studied at 40 °C and 50 °C using dynamic light scattering, analytical ultracentrifugation, size-exclusion chromatography and differential scanning calorimetry. At 40 °C the GDH aggregation proceeds through the slow stages of hexamer dissociation and formation of small oligomeric aggregates. At 50 °C these stages are transient. The rate-limiting stage of the overall aggregation process is unfolding of the protein molecule; the order of aggregation with respect to protein, n = 1. The test system based on GDH aggregation at 50 °C was used to quantify the anti-aggregation activity of chemical chaperones by comparing their half-saturation concentrations [L]0.5. Arginine ethyl ester had the highest anti-aggregation activity, with [L]0.5 = 4 ± 1 mM. For other additives, [L]0.5 was 22 ± 1 mM (arginine), 18 ± 1 mM (argininamide) and 95 ± 12 mM (proline). Arginine at concentrations up to 300 mM, argininamide at concentrations higher than 300 mM and arginine ethyl ester at concentrations higher than 500 mM enhance aggregate-aggregate sticking. These results explain the mechanism of heat-induced GDH aggregation and its peculiarities at different temperatures or in the presence of chemical chaperones.
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30
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Das N, Sen P. Macromolecular Crowding Effect on the Structure, Function, Conformational Dynamics and Relative Domain Movement of a Multi-Domain Protein as a function of Crowder Shape and Interaction. Phys Chem Chem Phys 2022; 24:14242-14256. [DOI: 10.1039/d1cp04842b] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The cellular environment is crowded by macromolecules of various sizes, shapes, and charges, which modulate protein structure, function and dynamics. Herein, we contemplated the effect of three different macromolecular crowders:...
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31
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Gruber T, Lewitzky M, Machner L, Weininger U, Feller SM, Balbach J. Macromolecular crowding induces a binding competent transient structure in intrinsically disordered Gab1. J Mol Biol 2021; 434:167407. [PMID: 34929201 DOI: 10.1016/j.jmb.2021.167407] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 12/09/2021] [Accepted: 12/10/2021] [Indexed: 10/19/2022]
Abstract
Intrinsically disordered proteins (IDPs) are an important class of proteins which lack tertiary structure elements. Their dynamic properties can depend on reversible post-translational modifications and the complex cellular milieu, which provides a crowded environment. Both influences the thermodynamic stability and folding of globular proteins as well as the conformational plasticity of IDPs. Here we investigate the intrinsically disordered C-terminal region (amino acids 613-694) of human Grb2-associated binding protein 1 (Gab1), which binds to the disease-relevant Src homolog region2 (SH2) domain-containing protein tyrosine phosphatase SHP2 (PTPN11). This binding is mediated by phosphorylation at Tyr 627 and Tyr 659 in Gab1. We characterize induced structure in Gab1613-694 and binding to SHP2 by NMR, CD and ITC under non-crowding and crowding conditions, employing chemical and biological crowding agents and compare the results of the non-phosphorylated and tyrosine phosphorylated C-terminal Gab1 fragment. Our results show that under crowding conditions pre-structured motifs in two distinct regions of Gab1 are formed whereas phosphorylation has no impact on the dynamics and IDP character. These structured regions are identical to the binding regions towards SHP2. Therefore, biological crowders could induce some SHP2 binding capacity. Our results therefore indicate that high concentrations of macromolecules stabilize the preformed or excited binding state in the C-terminal Gab1 region and foster the binding to the SH2 tandem motif of SHP2, even in the absence of tyrosine phosphorylation.
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Affiliation(s)
- Tobias Gruber
- Institute of Physics, Biophysics, Martin-Luther-University of Halle-Wittenberg, Germany; Institute of Molecular Medicine, Tumor Biology, Martin-Luther-University of Halle-Wittenberg, Germany
| | - Marc Lewitzky
- Institute of Molecular Medicine, Tumor Biology, Martin-Luther-University of Halle-Wittenberg, Germany
| | - Lisa Machner
- Institute of Molecular Medicine, Tumor Biology, Martin-Luther-University of Halle-Wittenberg, Germany
| | - Ulrich Weininger
- Institute of Physics, Biophysics, Martin-Luther-University of Halle-Wittenberg, Germany
| | - Stephan M Feller
- Institute of Molecular Medicine, Tumor Biology, Martin-Luther-University of Halle-Wittenberg, Germany.
| | - Jochen Balbach
- Institute of Physics, Biophysics, Martin-Luther-University of Halle-Wittenberg, Germany; Institute of Technical Biochemistry e.V. and Center for Structure and Dynamics of Proteins, Martin-Luther-University of Halle-Wittenberg, Germany.
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32
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Yi M, Tan W, Guo J, Xu B. Enzymatic noncovalent synthesis of peptide assemblies generates multimolecular crowding in cells for biomedical applications. Chem Commun (Camb) 2021; 57:12870-12879. [PMID: 34817487 PMCID: PMC8711086 DOI: 10.1039/d1cc05565h] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Enzymatic noncovalent synthesis enables the spatiotemporal control of multimolecular crowding in cells, thus offering a unique opportunity for modulating cellular functions. This article introduces some representative enzymes and molecular building blocks for generating peptide assemblies as multimolecular crowding in cells, highlights the relevant biomedical applications, such as anticancer therapy, molecular imaging, trafficking proteins, genetic engineering, artificial intracellular filaments, cell morphogenesis, and antibacterial, and briefly discusses the promises of ENS as a multistep molecular process in biology and medicine.
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Affiliation(s)
- Meihui Yi
- Department of Chemistry, Brandeis University, 415 South St., Waltham, MA 02454, USA.
| | - Weiyi Tan
- Department of Chemistry, Brandeis University, 415 South St., Waltham, MA 02454, USA.
| | - Jiaqi Guo
- Department of Chemistry, Brandeis University, 415 South St., Waltham, MA 02454, USA.
| | - Bing Xu
- Department of Chemistry, Brandeis University, 415 South St., Waltham, MA 02454, USA.
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33
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Köhn B, Schwarz P, Wittung-Stafshede P, Kovermann M. Impact of crowded environments on binding between protein and single-stranded DNA. Sci Rep 2021; 11:17682. [PMID: 34480058 PMCID: PMC8417293 DOI: 10.1038/s41598-021-97219-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 08/20/2021] [Indexed: 11/09/2022] Open
Abstract
The concept of Molecular Crowding depicts the high density of diverse molecules present in the cellular interior. Here, we determine the impact of low molecular weight and larger molecules on binding capacity of single-stranded DNA (ssDNA) to the cold shock protein B (CspB). Whereas structural features of ssDNA-bound CspB are fully conserved in crowded environments as probed by high-resolution NMR spectroscopy, intrinsic fluorescence quenching experiments reveal subtle changes in equilibrium affinity. Kinetic stopped-flow data showed that DNA-to-protein association is significantly retarded independent of choice of the molecule that is added to the solution, but dissociation depends in a nontrivial way on its size and chemical characteristics. Thus, for this DNA-protein interaction, excluded volume effect does not play the dominant role but instead observed effects are dictated by the chemical properties of the crowder. We propose that surrounding molecules are capable of specific modification of the protein's hydration shell via soft interactions that, in turn, tune protein-ligand binding dynamics and affinity.
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Affiliation(s)
- Birgit Köhn
- Department of Chemistry, University of Konstanz, Universitätsstrasse 10, 78457, Konstanz, Germany.,Konstanz Research School Chemical Biology KoRS-CB, University of Konstanz, Universitätsstrasse 10, 78457, Konstanz, Germany
| | - Patricia Schwarz
- Department of Chemistry, University of Konstanz, Universitätsstrasse 10, 78457, Konstanz, Germany
| | - Pernilla Wittung-Stafshede
- Department of Biology and Biological Engineering, Chalmers University of Technology, 41296, Gothenburg, Sweden
| | - Michael Kovermann
- Department of Chemistry, University of Konstanz, Universitätsstrasse 10, 78457, Konstanz, Germany. .,Konstanz Research School Chemical Biology KoRS-CB, University of Konstanz, Universitätsstrasse 10, 78457, Konstanz, Germany.
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34
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Shibata D, Kajimoto S, Nakabayashi T. Label-free tracking of intracellular molecular crowding with cell-cycle progression using Raman microscopy. Chem Phys Lett 2021. [DOI: 10.1016/j.cplett.2021.138843] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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35
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Rastogi H, Chowdhury PK. Understanding enzyme behavior in a crowded scenario through modulation in activity, conformation and dynamics. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2021; 1869:140699. [PMID: 34298166 DOI: 10.1016/j.bbapap.2021.140699] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 07/08/2021] [Accepted: 07/19/2021] [Indexed: 01/25/2023]
Abstract
Macromolecular crowding, inside the physiological interior, modulates the energy landscape of biological macromolecules in multiple ways. Amongst these, enzymes occupy a special place and hence understanding the function of the same in the crowded interior is of utmost importance. In this study, we have investigated the manner in which the multidomain enzyme, AK3L1 (PDB ID: 1ZD8), an isoform of adenylate kinase, has its features affected in presence of commonly used crowders (PEG 8, Dextran 40, Dextran 70, and Ficoll 70). Michaelis Menten plots reveal that the crowders in general enhance the activity of the enzyme, with the Km and Vmax values showing significant variations. Ficoll 70, induced the maximum activity for AK3L1 at 100 g/L, beyond which the activity reduced. Ensemble FRET studies were performed to provide insights into the relative domain (LID and CORE) displacements in presence of the crowders. Solvation studies reveal that the protein matrix surrounding the probe CPM (7-diethylamino-3-(4-maleimido-phenyl)-4-methylcoumarin) gets restricted in presence of the crowders, with Ficoll 70 providing the maximum rigidity, the same being linked to the decrease in the activity of the enzyme. Through our multipronged approach, we have observed a distinct correlation between domain displacement, enzyme activity and associated dynamics. Thus, keeping in mind the complex nature of enzyme activity and the surrounding bath of dense soup that the biological entity remains immersed in, indeed more such approaches need to be undertaken to have a better grasp of the "enzymes in the crowd".
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Affiliation(s)
- Harshita Rastogi
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Pramit K Chowdhury
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India.
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36
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Modeling protein association from homogeneous to mixed environments: A reaction-diffusion dynamics approach. J Mol Graph Model 2021; 107:107936. [PMID: 34139641 DOI: 10.1016/j.jmgm.2021.107936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 03/30/2021] [Accepted: 04/26/2021] [Indexed: 11/21/2022]
Abstract
Protein-protein association in vivo occur in a crowded and complex environment. Theoretical models based on hard-core repulsion predict stabilization of the product under crowded conditions. Soft interactions, on the contrary, can either stabilize or destabilize the product formation. Here we modeled protein association in presence of crowders of varying size, shape, interaction potential and used different mixing parameters for constituent crowders to study the influence on the association reaction. It was found that size is a more dominant factor in crowder-induced stabilization than the shape. Furthermore, in a mixture of crowders having different sizes but identical interaction potential, the change of free energy is additive of the free energy changes produced by individual crowders. However, the free energy change is not additive if two crowders of same size interact via different interaction potentials. These findings provide a systematic understanding of crowding influences in heterogeneous medium.
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37
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Dashnaw CM, Koone JC, Abdolvahabi A, Shaw BF. Measuring how two proteins affect each other's net charge in a crowded environment. Protein Sci 2021; 30:1594-1605. [PMID: 33928693 DOI: 10.1002/pro.4092] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 04/23/2021] [Indexed: 12/19/2022]
Abstract
Theory predicts that the net charge (Z) of a protein can be altered by the net charge of a neighboring protein as the two approach one another below the Debye length. This type of charge regulation suggests that a protein's charge and perhaps function might be affected by neighboring proteins without direct binding. Charge regulation during protein crowding has never been directly measured due to analytical challenges. Here, we show that lysine specific protein crosslinkers (NHS ester-Staudinger pairs) can be used to mimic crowding by linking two non-interacting proteins at a maximal distance of ~7.9 Å. The net charge of the regioisomeric dimers and preceding monomers can then be determined with lysine-acyl "protein charge ladders" and capillary electrophoresis. As a proof of concept, we covalently linked myoglobin (Zmonomer = -0.43 ± 0.01) and α-lactalbumin (Zmonomer = -4.63 ± 0.05). Amide hydrogen/deuterium exchange and circular dichroism spectroscopy demonstrated that crosslinking did not significantly alter the structure of either protein or result in direct binding (thus mimicking crowding). Ultimately, capillary electrophoretic analysis of the dimeric charge ladder detected a change in charge of ΔZ = -0.04 ± 0.09 upon crowding by this pair (Zdimer = -5.10 ± 0.07). These small values of ΔZ are not necessarily general to protein crowding (qualitatively or quantitatively) but will vary per protein size, charge, and solvent conditions.
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Affiliation(s)
- Chad M Dashnaw
- Department of Chemistry and Biochemistry, Baylor University, Waco, Texas, USA
| | - Jordan C Koone
- Department of Chemistry and Biochemistry, Baylor University, Waco, Texas, USA
| | - Alireza Abdolvahabi
- Mass Spectrometry Core Facility, School of Pharmacy, University of Southern California, Los Angeles, California, USA
| | - Bryan F Shaw
- Department of Chemistry and Biochemistry, Baylor University, Waco, Texas, USA
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38
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Labourel F, Rajon E. Resource uptake and the evolution of moderately efficient enzymes. Mol Biol Evol 2021; 38:3938-3952. [PMID: 33964160 PMCID: PMC8382906 DOI: 10.1093/molbev/msab132] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Enzymes speed up reactions that would otherwise be too slow to sustain the metabolism of selfreplicators. Yet, most enzymes seem only moderately efficient, exhibiting kinetic parameters orders of magnitude lower than their expected physically achievable maxima and spanning over surprisingly large ranges of values. Here, we question how these parameters evolve using a mechanistic model where enzyme efficiency is a key component of individual competition for resources. We show that kinetic parameters are under strong directional selection only up to a point, above which enzymes appear to evolve under near-neutrality, thereby confirming the qualitative observation of other modeling approaches. While the existence of a large fitness plateau could potentially explain the extensive variation in enzyme features reported, we show using a population genetics model that such a widespread distribution is an unlikely outcome of evolution on a common landscape, as mutation–selection–drift balance occupy a narrow area even when very moderate biases towards lower efficiency are considered. Instead, differences in the evolutionary context encountered by each enzyme should be involved, such that each evolves on an individual, unique landscape. Our results point to drift and effective population size playing an important role, along with the kinetics of nutrient transporters, the tolerance to high concentrations of intermediate metabolites, and the reversibility of reactions. Enzyme concentration also shapes selection on kinetic parameters, but we show that the joint evolution of concentration and efficiency does not yield extensive variance in evolutionary outcomes when documented costs to protein expression are applied.
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Affiliation(s)
- Florian Labourel
- Univ Lyon, Université Lyon 1, CNRS, Laboratoire de Biométrie et Biologie Evolutive UMR5558, Villeurbanne, F-69622, France
| | - Etienne Rajon
- Univ Lyon, Université Lyon 1, CNRS, Laboratoire de Biométrie et Biologie Evolutive UMR5558, Villeurbanne, F-69622, France
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39
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Fetahaj Z, Ostermeier L, Cinar H, Oliva R, Winter R. Biomolecular Condensates under Extreme Martian Salt Conditions. J Am Chem Soc 2021; 143:5247-5259. [PMID: 33755443 DOI: 10.1021/jacs.1c01832] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Biomolecular condensates formed by liquid-liquid phase separation (LLPS) are considered one of the early compartmentalization strategies of cells, which still prevail today forming nonmembranous compartments in biological cells. Studies of the effect of high pressures, such as those encountered in the subsurface salt lakes of Mars or in the depths of the subseafloor on Earth, on biomolecular LLPS will contribute to questions of protocell formation under prebiotic conditions. We investigated the effects of extreme environmental conditions, focusing on highly aggressive Martian salts (perchlorate and sulfate) and high pressure, on the formation of biomolecular condensates of proteins. Our data show that the driving force for phase separation of proteins is not only sensitively dictated by their amino acid sequence but also strongly influenced by the type of salt and its concentration. At high salinity, as encountered in Martian soil and similar harsh environments on Earth, attractive short-range interactions, ion correlation effects, hydrophobic, and π-driven interactions can sustain LLPS for suitable polypeptide sequences. Our results also show that salts across the Hofmeister series have a differential effect on shifting the boundary of immiscibility that determines phase separation. In addition, we show that confinement mimicking cracks in sediments and subsurface saline water pools in the Antarctica or on Mars can dramatically stabilize liquid phase droplets, leading to an increase in the temperature and pressure stability of the droplet phase.
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Affiliation(s)
- Zamira Fetahaj
- Physical Chemistry I - Biophysical Chemistry, Faculty of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn Street 4a, 44227 Dortmund, Germany
| | - Lena Ostermeier
- Physical Chemistry I - Biophysical Chemistry, Faculty of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn Street 4a, 44227 Dortmund, Germany
| | - Hasan Cinar
- Physical Chemistry I - Biophysical Chemistry, Faculty of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn Street 4a, 44227 Dortmund, Germany
| | - Rosario Oliva
- Physical Chemistry I - Biophysical Chemistry, Faculty of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn Street 4a, 44227 Dortmund, Germany
| | - Roland Winter
- Physical Chemistry I - Biophysical Chemistry, Faculty of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn Street 4a, 44227 Dortmund, Germany
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40
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Gruebele M, Pielak GJ. Dynamical spectroscopy and microscopy of proteins in cells. Curr Opin Struct Biol 2021; 70:1-7. [PMID: 33662744 DOI: 10.1016/j.sbi.2021.02.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 02/01/2021] [Indexed: 12/31/2022]
Abstract
With a strong understanding of how proteins fold in hand, it is now possible to ask how in-cell environments modulate their folding, binding and function. Studies accessing fast (ns to s) in-cell dynamics have accelerated over the past few years through a combination of in-cell NMR spectroscopy and time-resolved fluorescence microscopies. Here, we discuss this recent work and the emerging picture of protein surfaces as not just hydrophilic coats interfacing the solvent to the protein's core and functional regions, but as critical components in cells controlling protein mobility, function and communication with post-translational modifications.
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Affiliation(s)
- Martin Gruebele
- Department of Chemistry, Department of Physics, and Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
| | - Gary J Pielak
- Departments of Chemistry, Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599, USA.
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41
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Rufer AC. Drug discovery for enzymes. Drug Discov Today 2021; 26:875-886. [PMID: 33454380 DOI: 10.1016/j.drudis.2021.01.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 12/21/2020] [Accepted: 01/07/2021] [Indexed: 02/06/2023]
Abstract
Enzymes are essential, physiological catalysts involved in all processes of life, including metabolism, cellular signaling and motility, as well as cell growth and division. They are attractive drug targets because of the presence of defined substrate-binding pockets, which can be exploited as binding sites for pharmaceutical enzyme inhibitors. Understanding the reaction mechanisms of enzymes and the molecular mode of action of enzyme inhibitors is indispensable for the discovery and development of potent, efficacious, and safe novel drugs. The combination of classical concepts of enzymology with new experimental and data analysis methods opens new routes for drug discovery.
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Affiliation(s)
- Arne Christian Rufer
- Pharma Research and Early Development, Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, Grenzacherstrasse 124, 065/208A, 4070 Basel, Switzerland.
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42
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Gopan G, Gruebele M, Rickard M. In-cell protein landscapes: making the match between theory, simulation and experiment. Curr Opin Struct Biol 2020; 66:163-169. [PMID: 33254078 DOI: 10.1016/j.sbi.2020.10.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 10/10/2020] [Indexed: 11/26/2022]
Abstract
Theory, computation and experiment have matched up for the folding of small proteins in vitro, a difficult feat because folding energy landscapes are fairly smooth and free energy differences between states are small. Smoothness means that protein structure and folding are susceptible to the local environment inside living cells. Theory, computation and experiment are now exploring cellular modulation of energy landscapes. Interesting concepts have emerged, such as co-evolution of protein surfaces with their cellular environment to reduce detrimental interactions. Here we look at very recent work beginning to bring together theory, simulations and experiments in the area of protein landscape modulation, to see what problems might be solved in the near future by combining these approaches.
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Affiliation(s)
- Gopika Gopan
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Martin Gruebele
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA; Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
| | - Meredith Rickard
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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Köhn B, Kovermann M. All atom insights into the impact of crowded environments on protein stability by NMR spectroscopy. Nat Commun 2020; 11:5760. [PMID: 33188202 PMCID: PMC7666220 DOI: 10.1038/s41467-020-19616-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 10/23/2020] [Indexed: 01/16/2023] Open
Abstract
The high density of macromolecules affecting proteins due to volume exclusion has been discussed in theory but numerous in vivo experiments cannot be sufficiently understood taking only pure entropic stabilization into account. Here, we show that the thermodynamic stability of a beta barrel protein increases equally at all atomic levels comparing crowded environments with dilute conditions by applying multidimensional high-resolution NMR spectroscopy in a systematic manner. Different crowding agents evoke a pure stabilization cooperatively and do not disturb the surface or integrity of the protein fold. The here developed methodology provides a solid base that can be easily expanded to incorporate e.g. binding partners to recognize functional consequences of crowded conditions. Our results are relevant to research projects targeting soluble proteins in vivo as it can be anticipated that their thermodynamic stability increase comparably and has consequently to be taken into account to coherently understand intracellular processes.
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Affiliation(s)
- Birgit Köhn
- Department of Chemistry, University of Konstanz, Universitätsstrasse. 10, 78457, Konstanz, Germany
- Konstanz Research School Chemical Biology KoRS-CB, University of Konstanz, Universitätsstrasse. 10, 78457, Konstanz, Germany
| | - Michael Kovermann
- Department of Chemistry, University of Konstanz, Universitätsstrasse. 10, 78457, Konstanz, Germany.
- Konstanz Research School Chemical Biology KoRS-CB, University of Konstanz, Universitätsstrasse. 10, 78457, Konstanz, Germany.
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44
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Pittas T, Zuo W, Boersma AJ. Engineering crowding sensitivity into protein linkers. Methods Enzymol 2020; 647:51-81. [PMID: 33482994 DOI: 10.1016/bs.mie.2020.09.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The intracellular environment contains a high concentration of biomacromolecules that present steric barriers and ample surface area for weak chemical interactions. Consequently, these forces influence protein conformations and protein self-assembly, with an outcome that depends on the sum of the effects resulting from crowding. Linkers are disordered domains that lack tertiary structure, and this flexible nature would render them susceptible to compression or extension under crowded conditions, compared to the equilibrium conformation in a dilute buffer. The change in distance between the linked proteins can become essential where it attenuates protein activity. In this chapter, we first discuss the experimental findings in vitro and in the cell on how linkers and other relevant macromolecules are affected by crowding. We focus on the dependence on the linker's size, flexibility, and the intra- and intermolecular interactions. Although the experimental data on the systematic variation of proteins in a buffer and cells is limited, extrapolating the available insights allows us to propose a protocol on how to engineer the directionality of crowding effects in the linker. Finally, we describe a straightforward experimental protocol on the determination of crowding sensitivity in a buffer and cell.
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Affiliation(s)
- Theodoros Pittas
- DWI-Leibniz Institute for Interactive Materials, Aachen, Germany; Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, Aachen, Germany
| | - Weiyan Zuo
- DWI-Leibniz Institute for Interactive Materials, Aachen, Germany; Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, Aachen, Germany
| | - Arnold J Boersma
- DWI-Leibniz Institute for Interactive Materials, Aachen, Germany; Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, Aachen, Germany.
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45
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Abstract
Enzymatic reactions and noncovalent (i.e., supramolecular) interactions are two fundamental nongenetic attributes of life. Enzymatic noncovalent synthesis (ENS) refers to a process where enzymatic reactions control intermolecular noncovalent interactions for spatial organization of higher-order molecular assemblies that exhibit emergent properties and functions. Like enzymatic covalent synthesis (ECS), in which an enzyme catalyzes the formation of covalent bonds to generate individual molecules, ENS is a unifying theme for understanding the functions, morphologies, and locations of molecular ensembles in cellular environments. This review intends to provide a summary of the works of ENS within the past decade and emphasize ENS for functions. After comparing ECS and ENS, we describe a few representative examples where nature uses ENS, as a rule of life, to create the ensembles of biomacromolecules for emergent properties/functions in a myriad of cellular processes. Then, we focus on ENS of man-made (synthetic) molecules in cell-free conditions, classified by the types of enzymes. After that, we introduce the exploration of ENS of man-made molecules in the context of cells by discussing intercellular, peri/intracellular, and subcellular ENS for cell morphogenesis, molecular imaging, cancer therapy, and other applications. Finally, we provide a perspective on the promises of ENS for developing molecular assemblies/processes for functions. This review aims to be an updated introduction for researchers who are interested in exploring noncovalent synthesis for developing molecular science and technologies to address societal needs.
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Affiliation(s)
- Hongjian He
- Department of Chemistry, Brandeis University, 415 South Street, Waltham, Massachusetts 02454, United States
| | - Weiyi Tan
- Department of Chemistry, Brandeis University, 415 South Street, Waltham, Massachusetts 02454, United States
| | - Jiaqi Guo
- Department of Chemistry, Brandeis University, 415 South Street, Waltham, Massachusetts 02454, United States
| | - Meihui Yi
- Department of Chemistry, Brandeis University, 415 South Street, Waltham, Massachusetts 02454, United States
| | - Adrianna N Shy
- Department of Chemistry, Brandeis University, 415 South Street, Waltham, Massachusetts 02454, United States
| | - Bing Xu
- Department of Chemistry, Brandeis University, 415 South Street, Waltham, Massachusetts 02454, United States
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46
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Liquid-Liquid Phase Separation in Crowded Environments. Int J Mol Sci 2020; 21:ijms21165908. [PMID: 32824618 PMCID: PMC7460619 DOI: 10.3390/ijms21165908] [Citation(s) in RCA: 129] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 08/13/2020] [Indexed: 12/23/2022] Open
Abstract
Biomolecular condensates play a key role in organizing cellular fluids such as the cytoplasm and nucleoplasm. Most of these non-membranous organelles show liquid-like properties both in cells and when studied in vitro through liquid–liquid phase separation (LLPS) of purified proteins. In general, LLPS of proteins is known to be sensitive to variations in pH, temperature and ionic strength, but the role of crowding remains underappreciated. Several decades of research have shown that macromolecular crowding can have profound effects on protein interactions, folding and aggregation, and it must, by extension, also impact LLPS. However, the precise role of crowding in LLPS is far from trivial, as most condensate components have a disordered nature and exhibit multiple weak attractive interactions. Here, we discuss which factors determine the scope of LLPS in crowded environments, and we review the evidence for the impact of macromolecular crowding on phase boundaries, partitioning behavior and condensate properties. Based on a comparison of both in vivo and in vitro LLPS studies, we propose that phase separation in cells does not solely rely on attractive interactions, but shows important similarities to segregative phase separation.
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47
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In-cell destabilization of a homodimeric protein complex detected by DEER spectroscopy. Proc Natl Acad Sci U S A 2020; 117:20566-20575. [PMID: 32788347 DOI: 10.1073/pnas.2005779117] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The complexity of the cellular medium can affect proteins' properties, and, therefore, in-cell characterization of proteins is essential. We explored the stability and conformation of the first baculoviral IAP repeat (BIR) domain of X chromosome-linked inhibitor of apoptosis (XIAP), BIR1, as a model for a homodimer protein in human HeLa cells. We employed double electron-electron resonance (DEER) spectroscopy and labeling with redox stable and rigid Gd3+ spin labels at three representative protein residues, C12 (flexible region), E22C, and N28C (part of helical residues 26 to 31) in the N-terminal region. In contrast to predictions by excluded-volume crowding theory, the dimer-monomer dissociation constant K D was markedly higher in cells than in solution and dilute cell lysate. As expected, this increase was partially recapitulated under conditions of high salt concentrations, given that conserved salt bridges at the dimer interface are critically required for association. Unexpectedly, however, also the addition of the crowding agent Ficoll destabilized the dimer while the addition of bovine serum albumin (BSA) and lysozyme, often used to represent interaction with charged macromolecules, had no effect. Our results highlight the potential of DEER for in-cell study of proteins as well as the complexities of the effects of the cellular milieu on protein structures and stability.
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Savojardo C, Martelli PL, Casadio R. Protein–Protein Interaction Methods and Protein Phase Separation. Annu Rev Biomed Data Sci 2020. [DOI: 10.1146/annurev-biodatasci-011720-104428] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
In the last decade, newly developed experimental methods have made it possible to highlight that macromolecules in the cell milieu physically interact to support physiology. This has shifted the problem of protein–protein interaction from a microscopic, electron-density scale to a mesoscopic one. Further, nowadays there is increasing evidence that proteins in the nucleus and in the cytoplasm can aggregate in membraneless organelles for different physiological reasons. In this scenario, it is urgent to face the problem of biomolecule functional annotation with efficient computational methods, suited to extract knowledge from reliable data and transfer information across different domains of investigation. Here, we revise the present state of the art of our knowledge of protein–protein interaction and the computational methods that differently implement it. Furthermore, we explore experimental and computational features of a set of proteins involved in phase separation.
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Affiliation(s)
- Castrense Savojardo
- Biocomputing Group, Department of Pharmacy and Biotechnology and Interdepartmental Center “Luigi Galvani” for Integrated Studies of Bioinformatics, Biophysics, and Biocomplexity, University of Bologna, 40126 Bologna, Italy
| | - Pier Luigi Martelli
- Biocomputing Group, Department of Pharmacy and Biotechnology and Interdepartmental Center “Luigi Galvani” for Integrated Studies of Bioinformatics, Biophysics, and Biocomplexity, University of Bologna, 40126 Bologna, Italy
| | - Rita Casadio
- Biocomputing Group, Department of Pharmacy and Biotechnology and Interdepartmental Center “Luigi Galvani” for Integrated Studies of Bioinformatics, Biophysics, and Biocomplexity, University of Bologna, 40126 Bologna, Italy
- Institute of Biomembranes, Bioenergetics, and Molecular Biotechnologies (IBIOM), Italian National Research Council (CNR), 70126 Bari, Italy
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Monterroso B, Robles-Ramos MÁ, Zorrilla S, Rivas G. Reconstituting bacterial cell division assemblies in crowded, phase-separated media. Methods Enzymol 2020; 646:19-49. [PMID: 33453926 DOI: 10.1016/bs.mie.2020.06.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Here we have summarized several strategies to reconstruct complexes containing the FtsZ protein, a central element of the cell division machinery in most bacteria, and to test their functional organization in minimal membrane systems and cell-like containers, as vesicles and droplets produced by microfluidics. These synthetic systems have been devised to mimic elements of the intracellular complexity, as excluded volume effects due to natural crowding, and macromolecular condensation resulting from biologically regulated liquid-liquid phase separation, in media of known and controllable composition. This integrative approach has allowed to demonstrate that macromolecular phase separation and crowding may also help to dynamically organize FtsZ in the intracellular space thus modulating its functional reactivity in cell division.
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Affiliation(s)
- Begoña Monterroso
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain.
| | - Miguel Ángel Robles-Ramos
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Silvia Zorrilla
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain.
| | - Germán Rivas
- Centro de Investigaciones Biológicas Margarita Salas, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain.
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50
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Nearest-neighbor parameters for predicting DNA duplex stability in diverse molecular crowding conditions. Proc Natl Acad Sci U S A 2020; 117:14194-14201. [PMID: 32522884 DOI: 10.1073/pnas.1920886117] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The intracellular environment is crowded and heterogeneous. Although the thermodynamic stability of nucleic acid duplexes is predictable in dilute solutions, methods of predicting such stability under specific intracellular conditions are not yet available. We recently showed that the nearest-neighbor model for self-complementary DNA is valid under molecular crowding condition of 40% polyethylene glycol with an average molecular weight of 200 (PEG 200) in 100 mM NaCl. Here, we determined nearest-neighbor parameters for DNA duplex formation under the same crowding condition to predict the thermodynamics of DNA duplexes in the intracellular environment. Preferential hydration of the nucleotides was found to be the key factor for nearest-neighbor parameters in the crowding condition. The determined parameters were shown to predict the thermodynamic parameters (∆H°, ∆S°, and ∆G°37) and melting temperatures (T m) of the DNA duplexes in the crowding condition with significant accuracy. Moreover, we proposed a general method for predicting the stability of short DNA duplexes in different cosolutes based on the relationship between duplex stability and the water activity of the cosolute solution. The method described herein would be valuable for investigating biological processes that occur under specific intracellular crowded conditions and for the application of DNA-based biotechnologies in crowded environments.
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