1
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Holkar A, Gao S, Villaseñor K, Lake M, Srivastava S. Quantitative turbidimetric characterization of stabilized complex coacervate dispersions. SOFT MATTER 2024; 20:5060-5070. [PMID: 38743276 DOI: 10.1039/d3sm01761c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
Stabilizing complex coacervate microdroplets is desirable due to their various applications, such as bioreactors, drug delivery vehicles, and encapsulants. Here, we present quantitative characterization of complex coacervate dispersion stability inferred by turbidimetry measurements. The stability of the dispersions is shown to be modulated by the concentrations of comb polyelectrolyte (cPE) stabilizers and salt. We demonstrate cPEs as effective stabilizers for complex coacervate dispersions independent of the chemistry or length of the constituent polyelectrolytes, salts, or preparation routes. By monitoring the temporal evolution of dispersion turbidity, we show that cPEs suppress microdroplet coalescence with minimal change in microdroplet sizes over 48 hours, even at salt concentrations up to 300 mM. The number density and average microdroplet size are shown to be controlled by varying the cPE and salt concentrations. Lastly, turbidity maps, akin to binodal phase maps, depict an expansion of the turbid two-phase region and an increase in the salt resistance of the coacervates upon the introduction of cPEs. The coacervate salt resistance is shown to increase by >3×, and this increase is maintained for up to 15 days, demonstrating that cPEs impart higher salt resistance over extended durations.
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Affiliation(s)
- Advait Holkar
- Chemical and Biomolecular Engineering, University of California, Los Angeles, Los Angeles, CA 90095, USA.
| | - Shang Gao
- Chemical and Biomolecular Engineering, University of California, Los Angeles, Los Angeles, CA 90095, USA.
| | - Kathleen Villaseñor
- Chemical and Biomolecular Engineering, University of California, Los Angeles, Los Angeles, CA 90095, USA.
| | - Michael Lake
- NSF BioPACIFIC MIP, University of California, Los Angeles, Los Angeles, CA 90095, USA
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Samanvaya Srivastava
- Chemical and Biomolecular Engineering, University of California, Los Angeles, Los Angeles, CA 90095, USA.
- NSF BioPACIFIC MIP, University of California, Los Angeles, Los Angeles, CA 90095, USA
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA
- Institute for Carbon Management, University of California, Los Angeles, Los Angeles, CA 90095, USA
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2
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Zhao Z, Baltar F, Herndl GJ. Decoupling between the genetic potential and the metabolic regulation and expression in microbial organic matter cleavage across microbiomes. Microbiol Spectr 2024; 12:e0303623. [PMID: 38511953 PMCID: PMC11210215 DOI: 10.1128/spectrum.03036-23] [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: 08/04/2023] [Accepted: 03/06/2024] [Indexed: 03/22/2024] Open
Abstract
Metagenomics, metatranscriptomics, and metaproteomics are used to explore the microbial capability of enzyme secretion, but the links between protein-encoding genes and corresponding transcripts/proteins across ecosystems are underexplored. By conducting a multi-omics comparison focusing on key enzymes (carbohydrate-active enzymes [CAZymes] and peptidases) cleaving the main biomolecules across distinct microbiomes living in the ocean, soil, and human gut, we show that the community structure, functional diversity, and secretion mechanisms of microbial secretory CAZymes and peptidases vary drastically between microbiomes at metagenomic, metatranscriptomic, and metaproteomic levels. Such variations lead to decoupled relationships between CAZymes and peptidases from genetic potentials to protein expressions due to the different responses of key players toward organic matter sources and concentrations. Our results highlight the need for systematic analysis of the factors shaping patterns of microbial cleavage on organic matter to better link omics data to ecosystem processes. IMPORTANCE Omics tools are used to explore adaptive mechanism of microbes in diverse systems, but the advantages and limitations of different omics tools remain skeptical. Here, we reported distinct profiles in microbial secretory enzyme composition revealed by different omics methods. In general, the predicted function from metagenomic analysis decoupled from the expression of corresponding transcripts/proteins. Linking omics results to taxonomic origin, functional capability, substrate specificity, secretion preference, and enzymatic activity measurement suggested the substrate's source, concentration and stoichiometry impose strong filtering on the expression of extracellular enzymes, which may overwrite the genetic potentials. Our results present an integrated perspective on the need for multi-dimensional characterization of microbial adaptation in a changing environment.
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Affiliation(s)
- Zihao Zhao
- Department of Functional and Evolutionary Ecology, Bio-Oceanography Unit, University of Vienna, Vienna, Austria
| | - Federico Baltar
- Department of Functional and Evolutionary Ecology, Bio-Oceanography Unit, University of Vienna, Vienna, Austria
| | - Gerhard J. Herndl
- Department of Functional and Evolutionary Ecology, Bio-Oceanography Unit, University of Vienna, Vienna, Austria
- NIOZ, Department of Marine Microbiology and Biogeochemistry, Royal Netherlands Institute for Sea Research, Den Burg, the Netherlands
- Vienna Metabolomics Center, University of Vienna, Vienna, Austria
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3
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Grassmann G, Miotto M, Desantis F, Di Rienzo L, Tartaglia GG, Pastore A, Ruocco G, Monti M, Milanetti E. Computational Approaches to Predict Protein-Protein Interactions in Crowded Cellular Environments. Chem Rev 2024; 124:3932-3977. [PMID: 38535831 PMCID: PMC11009965 DOI: 10.1021/acs.chemrev.3c00550] [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: 07/31/2023] [Revised: 02/20/2024] [Accepted: 02/21/2024] [Indexed: 04/11/2024]
Abstract
Investigating protein-protein interactions is crucial for understanding cellular biological processes because proteins often function within molecular complexes rather than in isolation. While experimental and computational methods have provided valuable insights into these interactions, they often overlook a critical factor: the crowded cellular environment. This environment significantly impacts protein behavior, including structural stability, diffusion, and ultimately the nature of binding. In this review, we discuss theoretical and computational approaches that allow the modeling of biological systems to guide and complement experiments and can thus significantly advance the investigation, and possibly the predictions, of protein-protein interactions in the crowded environment of cell cytoplasm. We explore topics such as statistical mechanics for lattice simulations, hydrodynamic interactions, diffusion processes in high-viscosity environments, and several methods based on molecular dynamics simulations. By synergistically leveraging methods from biophysics and computational biology, we review the state of the art of computational methods to study the impact of molecular crowding on protein-protein interactions and discuss its potential revolutionizing effects on the characterization of the human interactome.
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Affiliation(s)
- Greta Grassmann
- Department
of Biochemical Sciences “Alessandro Rossi Fanelli”, Sapienza University of Rome, Rome 00185, Italy
- Center
for Life Nano & Neuro Science, Istituto
Italiano di Tecnologia, Rome 00161, Italy
| | - Mattia Miotto
- Center
for Life Nano & Neuro Science, Istituto
Italiano di Tecnologia, Rome 00161, Italy
| | - Fausta Desantis
- Center
for Life Nano & Neuro Science, Istituto
Italiano di Tecnologia, Rome 00161, Italy
- The
Open University Affiliated Research Centre at Istituto Italiano di
Tecnologia, Genoa 16163, Italy
| | - Lorenzo Di Rienzo
- Center
for Life Nano & Neuro Science, Istituto
Italiano di Tecnologia, Rome 00161, Italy
| | - Gian Gaetano Tartaglia
- Center
for Life Nano & Neuro Science, Istituto
Italiano di Tecnologia, Rome 00161, Italy
- Department
of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, Genoa 16163, Italy
- Center
for Human Technologies, Genoa 16152, Italy
| | - Annalisa Pastore
- Experiment
Division, European Synchrotron Radiation
Facility, Grenoble 38043, France
| | - Giancarlo Ruocco
- Center
for Life Nano & Neuro Science, Istituto
Italiano di Tecnologia, Rome 00161, Italy
- Department
of Physics, Sapienza University, Rome 00185, Italy
| | - Michele Monti
- RNA
System Biology Lab, Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, Genoa 16163, Italy
| | - Edoardo Milanetti
- Center
for Life Nano & Neuro Science, Istituto
Italiano di Tecnologia, Rome 00161, Italy
- Department
of Physics, Sapienza University, Rome 00185, Italy
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4
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Heravi S, Power JVD, Yethiraj A, Booth V. The effects of biological crowders on fibrillization, structure, diffusion, and conformational dynamics of α-synuclein. Protein Sci 2024; 33:e4894. [PMID: 38358134 PMCID: PMC10868423 DOI: 10.1002/pro.4894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 12/28/2023] [Accepted: 12/29/2023] [Indexed: 02/16/2024]
Abstract
α-synuclein is an intrinsically disordered protein (IDP) whose aggregation in presynaptic neuronal cells is a pathological hallmark of Lewy body formation and Parkinson's disease. This aggregation process is likely affected by the crowded macromolecular cellular environment. In this study, α-synuclein was studied in the presence of both a synthetic crowder, Ficoll70, and a biological crowder composed of lysed cells that better mimics the biocomplexity of the cellular environment. 15 N-1 H HSQC NMR results show similar α-synuclein chemical shifts in non-crowded and all crowded conditions implying that it remains similarly unstructured in all conditions. Nevertheless, both HSQC NMR and fluorescence measurements indicate that, only in the cell lysate, α-synuclein forms aggregates over a timescale of 48 h. 15 N-edited diffusion measurements indicate that all crowders slow down the α-synuclein's diffusivity. Interestingly, at high concentrations, α-synuclein diffuses faster in cell lysate than in Ficoll70, possibly due to additional soft (e.g., electrostatic or hydrophobic) interactions. 15 N-edited relaxation measurements show that some residues are more mobile in cell lysate than in Ficoll70; the rates that are most different are predominantly in hydrophobic residues. We thus examined cell lysates with reduced hydrophobicity and found slower dynamics (higher relaxation rates) in several α-synuclein residues. Taken together, these experiments suggest that while cell lysate does not substantially affect α-synuclein structure (HSQC spectra), it does affect chain dynamics and translational diffusion, and strongly affects aggregation over a timescale of days, in a manner that is different from either no crowder or an artificial crowder: soft hydrophobic interactions are implicated.
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Affiliation(s)
- Sina Heravi
- Department of BiochemistryMemorial University of NewfoundlandSt. John'sNewfoundland and LabradorCanada
| | - Jude Vincent Dobbin Power
- Department of BiochemistryMemorial University of NewfoundlandSt. John'sNewfoundland and LabradorCanada
| | - Anand Yethiraj
- Department of Physics and Physical OceanographyMemorial University of NewfoundlandSt. John'sNewfoundland and LabradorCanada
| | - Valerie Booth
- Department of BiochemistryMemorial University of NewfoundlandSt. John'sNewfoundland and LabradorCanada
- Department of Physics and Physical OceanographyMemorial University of NewfoundlandSt. John'sNewfoundland and LabradorCanada
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5
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Biswas S, Hecht AL, Noble SA, Huang Q, Gillilan RE, Xu AY. Understanding the Impacts of Molecular and Macromolecular Crowding Agents on Protein-Polymer Complex Coacervates. Biomacromolecules 2023; 24:4771-4782. [PMID: 37815312 PMCID: PMC10646951 DOI: 10.1021/acs.biomac.3c00545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 09/25/2023] [Indexed: 10/11/2023]
Abstract
Complex coacervation refers to the liquid-liquid phase separation (LLPS) process occurring between charged macromolecules. The study of complex coacervation is of great interest due to its implications in the formation of membraneless organelles (MLOs) in living cells. However, the impacts of the crowded intracellular environment on the behavior and interactions of biomolecules involved in MLO formation are not fully understood. To address this knowledge gap, we investigated the effects of crowding on a model protein-polymer complex coacervate system. Specifically, we examined the influence of sucrose as a molecular crowder and polyethylene glycol (PEG) as a macromolecular crowder. Our results reveal that the presence of crowders led to the formation of larger coacervate droplets that remained stable over a 25-day period. While sucrose had a minimal effect on the physical properties of the coacervates, PEG led to the formation of coacervates with distinct characteristics, including higher density, increased protein and polymer content, and a more compact internal structure. These differences in coacervate properties can be attributed to the effects of crowders on individual macromolecules, such as the conformation of model polymers, and nonspecific interactions among model protein molecules. Moreover, our results show that sucrose and PEG have different partition behaviors: sucrose was present in both the coacervate and dilute phases, while PEG was observed to be excluded from the coacervate phase. Collectively, our findings provide insights into the understanding of crowding effects on complex coacervation, shedding light on the formation and properties of coacervates in the context of MLOs.
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Affiliation(s)
- Shanta Biswas
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, United States
| | - Alison L Hecht
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, United States
| | - Sadie A Noble
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, United States
| | - Qingqiu Huang
- Cornell High Energy Synchrotron Source (CHESS), Cornell University, Ithaca, New York 14853, United States
| | - Richard E Gillilan
- Cornell High Energy Synchrotron Source (CHESS), Cornell University, Ithaca, New York 14853, United States
| | - Amy Y Xu
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, United States
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6
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Zong Y, Xu SM, Shi W, Lu C. Chiral Hierarchical Architecture Induced by Confinement-Assisted Living Supramolecular Polymerization of Simple Achiral Molecules. ACS NANO 2023; 17:3838-3846. [PMID: 36779509 DOI: 10.1021/acsnano.2c12063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Chiral supramolecular assembly (CSA) based on achiral molecules has provided important clues to understand the origin of biological chirality. However, a simple achiral monomer faces the challenge of chiral stacking with the absence of a chiral resource. The difficulty is that simple achiral monomer lacks steric repulsion to provide asymmetry during hierarchical assembly, which is a prerequisite for chiral stacking with an angle. Moreover, during chiral stacking of achiral molecules or units, the right-handed and left-handed chiral supramolecular isomers (CSIs) are equally formed due to the mirror-imaged conformation, which leads to chirality silence. Here, with the benefit of two-dimensional confinement space of layered double hydroxide (LDH), simple achiral molecules can be arranged to staggered bilayer arrays by imprinting the topological structure of LDH. Once LDH is removed, these staggered arrays can form asymmetric living seeds, which can further elongate to living units with the advantage of living supramolecular polymerization (LSP) by following off-pathway. Due to the asymmetry of living units, the possible chiral stacking outcomes, CSIs, are not mirror-imaged. With the increase of the molecular number in living units, the energy difference between CSIs can be amplified by self-replication of LSP, leading to handedness preference. Thus, the detectable CSA is mainly derived from the CSI with energetically favored hierarchical structure. Thus, our strategy breaks the stereotype that the complex molecular structure and symmetry breaking mechanism are necessary for the formation of detectable CSA by achiral molecules.
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Affiliation(s)
- Yingtong Zong
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, 15 Beisanhuan East Road, P. Box 98, 100029 Beijing, P. R. China
- Jiangxi Key Laboratory of Organo-Pharmaceutical Chemistry, College of Chemistry and Chemical Engineering, Gannan Normal University, 341000 Ganzhou, Jiangxi, P. R. China
| | - Si-Min Xu
- Jiangxi Key Laboratory of Organo-Pharmaceutical Chemistry, College of Chemistry and Chemical Engineering, Gannan Normal University, 341000 Ganzhou, Jiangxi, P. R. China
| | - Wenying Shi
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, 15 Beisanhuan East Road, P. Box 98, 100029 Beijing, P. R. China
| | - Chao Lu
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, 15 Beisanhuan East Road, P. Box 98, 100029 Beijing, P. R. China
- Green Catalysis Center, College of Chemistry, Zhengzhou University, 450001 Zhengzhou, P. R. China
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7
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Connecting the Dots: Macromolecular Crowding and Protein Aggregation. J Fluoresc 2023; 33:1-11. [PMID: 36417150 DOI: 10.1007/s10895-022-03082-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 11/09/2022] [Indexed: 11/24/2022]
Abstract
Proteins are one of the dynamic macromolecules that play a significant role in many physiologically important processes to sustain life on the earth. Proteins need to be properly folded into their active conformation to perform their function. Alteration in the protein folding process may lead to the formation of misfolded conformers. Accumulation of these misfolded conformers can result in the formation of protein aggregates which are attributed to many human pathological conditions including neurodegeneration, cataract, neuromuscular disorders, and diabetes. Living cells naturally have heterogeneous crowding environments with different concentrations of various biomolecules. Macromolecular crowding condition has been found to alter the protein conformation. Here in this review, we tried to show the relation between macromolecular crowding, protein aggregation, and its consequences.
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8
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Raina N, Hassan MI, Ahmad F, Islam A, Singh AK. PEG mediated destabilization of holo α-lactalbumin probed by in silico and in vitro studies: deviation from excluded volume effect. J Biomol Struct Dyn 2022; 40:13265-13277. [PMID: 34726117 DOI: 10.1080/07391102.2021.1987990] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Crowded and confined macromolecular milieus surround proteins, and both are stabilizing if the nature of the interaction between crowder and proteins are considered hard-core repulsive interactions. However, non-specific chemical interactions between a protein and its surroundings also play a significant role and the sum effect of both hard-core repulsion and soft interaction balances the overall effect of crowding/confinement. Previous studies showing the effect of polyethylene glycol (PEG) on protein and nucleic acid may be interpreted as either primarily excluded volume effect or, in some cases, chemical effect by changing solvent properties. In case of destabilizing interactions, charge-charge and hydrophobic contact have to gain more attention. For instance, in vitro and in vivo studies using protein as crowding agent revealed the destabilization of proteins induced by charge-charge interactions. To investigate the effect of PEG 10 kDa on holo α-lactalbumin (holo α-LA), structure and thermal stability of the protein were measured at different pH values using several techniques. Structural characterization by Trp-fluorescence, near-UV CD and far-UV measurements at different pH values clearly shows perturbation of tertiary and secondary structure of holo α-LA by PEG 10 kDa. Furthermore, the dynamic light scattering measurement shows that the protein is homogeneous under all experimental conditions. Analysis of the heat-induced denaturation profile in the presence of the crowder shows destabilization of the protein in terms of Tm (midpoint of denaturation) and ΔGD0 (Gibbs free energy change at 25 °C). To evaluate the interaction of PEG 10 kDa with holo α-LA and stability of PEG-α-LA complex, docking and molecular dynamic simulation were carried out for 100 ns.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Neha Raina
- Department of Biotechnology, Sharda University, Greater Noida, Uttar Pradesh, India.,Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, New Delhi, Delhi, India
| | - Md Imtaiyaz Hassan
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, New Delhi, Delhi, India
| | - Faizan Ahmad
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, New Delhi, Delhi, India
| | - Asimul Islam
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, New Delhi, Delhi, India
| | - Amit Kumar Singh
- Department of Biotechnology, Sharda University, Greater Noida, Uttar Pradesh, India
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9
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Jenkins NW, Kundrotas PJ, Vakser IA. Size of the protein-protein energy funnel in crowded environment. Front Mol Biosci 2022; 9:1031225. [PMID: 36425657 PMCID: PMC9679368 DOI: 10.3389/fmolb.2022.1031225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 10/26/2022] [Indexed: 11/09/2022] Open
Abstract
Association of proteins to a significant extent is determined by their geometric complementarity. Large-scale recognition factors, which directly relate to the funnel-like intermolecular energy landscape, provide important insights into the basic rules of protein recognition. Previously, we showed that simple energy functions and coarse-grained models reveal major characteristics of the energy landscape. As new computational approaches increasingly address structural modeling of a whole cell at the molecular level, it becomes important to account for the crowded environment inside the cell. The crowded environment drastically changes protein recognition properties, and thus significantly alters the underlying energy landscape. In this study, we addressed the effect of crowding on the protein binding funnel, focusing on the size of the funnel. As crowders occupy the funnel volume, they make it less accessible to the ligands. Thus, the funnel size, which can be defined by ligand occupancy, is generally reduced with the increase of the crowders concentration. This study quantifies this reduction for different concentration of crowders and correlates this dependence with the structural details of the interacting proteins. The results provide a better understanding of the rules of protein association in the crowded environment.
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Affiliation(s)
- Nathan W. Jenkins
- Computational Biology Program, The University of Kansas, Lawrence, KS, United States
| | - Petras J. Kundrotas
- Computational Biology Program, The University of Kansas, Lawrence, KS, United States
- *Correspondence: Petras J. Kundrotas, ; Ilya A. Vakser,
| | - Ilya A. Vakser
- Computational Biology Program, The University of Kansas, Lawrence, KS, United States
- Department of Molecular Biosciences, The University of Kansas, Lawrence, KS, United States
- *Correspondence: Petras J. Kundrotas, ; Ilya A. Vakser,
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10
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Bedi S, Kumar G, Rose SM, Rakshit S, Sinha S. Barrier-free liquid condensates of nanocatalysts as effective concentrators of catalysis. Chem Commun (Camb) 2022; 58:8634-8637. [PMID: 35819054 DOI: 10.1039/d2cc03111f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Traditional methods of molecular confinement have physicochemical barriers that restrict the free passage of substrates/products. Here, we explored liquid-liquid phase separation as a method to restrain protein-metal nanocomposites within barrier-free condensates. Confinement within liquid droplets was independent of the protein's native conformation and amplified the catalytic efficiency of metal nanocatalysts by one order of magnitude.
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Affiliation(s)
- Silky Bedi
- Chemical Biology Unit, Institute of Nano Science and Technology, Sector-81, Knowledge City, Sahibzada Ajit Singh Nagar, Punjab, 140306, India.
| | - Gaurav Kumar
- Chemical Biology Unit, Institute of Nano Science and Technology, Sector-81, Knowledge City, Sahibzada Ajit Singh Nagar, Punjab, 140306, India.
| | - S M Rose
- Chemical Biology Unit, Institute of Nano Science and Technology, Sector-81, Knowledge City, Sahibzada Ajit Singh Nagar, Punjab, 140306, India.
| | - Sabyasachi Rakshit
- Department of Chemical Sciences, Indian Institute of Science Education and Research, Sector-81, Knowledge City, Sahibzada Ajit Singh Nagar, Punjab, 140306, India.
| | - Sharmistha Sinha
- Chemical Biology Unit, Institute of Nano Science and Technology, Sector-81, Knowledge City, Sahibzada Ajit Singh Nagar, Punjab, 140306, India.
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11
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Parray ZA, Ahmad F, Chaudhary AA, Rudayni HA, Al-Zharani M, Hassan MI, Islam A. Size-Dependent Interplay of Volume Exclusion Versus Soft Interactions: Cytochrome c in Macromolecular Crowded Environment. Front Mol Biosci 2022; 9:849683. [PMID: 35693552 PMCID: PMC9174945 DOI: 10.3389/fmolb.2022.849683] [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: 01/06/2022] [Accepted: 02/28/2022] [Indexed: 12/03/2022] Open
Abstract
Even though there are a great number of possible conformational states, how a protein generated as a linear unfolded polypeptide efficiently folds into its physiologically active form remained a fascinating and unanswered enigma inside crowded conditions of cells. In this study, various spectroscopic techniques have been exploited to know and understand the effect and mechanism of action of two different sizes of polyethylene glycols, or PEGs (molecular mass ∼10 and ∼20 kilo Daltons, kDa), on cytochrome c (cyt c). The outcomes showed that small size of the PEG leads to perturbation of the protein structure, and conversely, large size of the PEG has stabilizing effect on cyt c. Moreover, binding measurements showed that small size of PEG interacts strongly via soft interactions compared to the larger size of PEG, the latter being governed more by excluded volume effect or preferential exclusion from the protein. Overall, this finding suggests that conformations of protein may be influenced in cellular crowded conditions via interactions which depend upon the size of molecule in the environment. This study proposes that both volume exclusion and soft (chemical) interactions governs the protein’s conformation and functional activities. The cellular environment’s internal architecture as evident from crowder size and shape in this study has a significant role.
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Affiliation(s)
- Zahoor Ahmad Parray
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, New Delhi, India
- Department of Chemistry, Indian Institute of Technology Delhi, New Delhi, India
| | - Faizan Ahmad
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, New Delhi, India
- Department of Biochemistry, School of Chemical and Life Sciences, Jamia Hamdard, New Delhi, India
| | - Anis Ahmad Chaudhary
- Department of Biology, College of Science, Imam Mohammad Ibn Saud Islamic University (IMSIU), Riyadh, Saudi Arabia
| | - Hassan Ahmad Rudayni
- Department of Biology, College of Science, Imam Mohammad Ibn Saud Islamic University (IMSIU), Riyadh, Saudi Arabia
| | - Mohammed Al-Zharani
- Department of Biology, College of Science, Imam Mohammad Ibn Saud Islamic University (IMSIU), Riyadh, Saudi Arabia
| | - Md. Imtaiyaz Hassan
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, New Delhi, India
| | - Asimul Islam
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, New Delhi, India
- *Correspondence: Asimul Islam,
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12
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Rajendran D, Mitra S, Oikawa H, Madhurima K, Sekhar A, Takahashi S, Naganathan AN. Quantification of Entropic Excluded Volume Effects Driving Crowding-Induced Collapse and Folding of a Disordered Protein. J Phys Chem Lett 2022; 13:3112-3120. [PMID: 35357183 PMCID: PMC7612738 DOI: 10.1021/acs.jpclett.2c00316] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
We investigate the conformational properties of the intrinsically disordered DNA-binding domain of CytR in the presence of the polymeric crowder polyethylene glycol (PEG). Integrating circular dichroism, nuclear magnetic resonance, and single-molecule Förster resonance energy transfer measurements, we demonstrate that disordered CytR populates a well-folded minor conformation in its native ensemble, while the unfolded ensemble collapses and folds with an increase in crowder density independent of the crowder size. Employing a statistical-mechanical model, the effective reduction in the accessible conformational space of a residue in the unfolded state is estimated to be 10% at 300 mg/mL PEG8000, relative to dilute conditions. The experimentally consistent PEG-temperature phase diagram thus constructed reveals that entropic effects can stabilize disordered CytR by 10 kJ mol-1, driving the equilibrium toward folded conformations under physiological conditions. Our work highlights the malleable conformational landscape of CytR, the presence of a folded conformation in the disordered ensemble, and proposes a scaling relation for quantifying excluded volume effects on protein stability.
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Affiliation(s)
- Divya Rajendran
- Department of Biotechnology, Bhupat & Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai 600036, India
| | - Shrutarshi Mitra
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan
- Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan
| | - Hiroyuki Oikawa
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan
- Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan
| | - Kulkarni Madhurima
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560012, India
| | - Ashok Sekhar
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560012, India
| | - Satoshi Takahashi
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan
- Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan
| | - Athi N Naganathan
- Department of Biotechnology, Bhupat & Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai 600036, India
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13
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Contessoto VG, Ferreira PHB, Chahine J, Leite VBP, Oliveira RJ. Small Neutral Crowding Solute Effects on Protein Folding Thermodynamic Stability and Kinetics. J Phys Chem B 2021; 125:11673-11686. [PMID: 34644091 DOI: 10.1021/acs.jpcb.1c07663] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Molecular crowding is a ubiquitous phenomenon in biological systems, with significant consequences on protein folding and stability. Small compounds, such as the osmolyte trimethylamine N-oxide (TMAO), can also present similar effects. To analyze the effects arising from these solute-like molecules, we performed a series of crowded coarse-grained folding simulations. Two well-known proteins were chosen, CI2 and SH3, modeled by the alpha-carbon-structure-based model. In the simulations, the crowding molecules were represented by low-sized neutral atom beads in different concentrations. The results show that a low level of the volume fraction occupied by neutral agents can change protein stability and folding kinetics for the two systems. However, the kinetics were shown to be unaffected in their respective folding temperatures. The faster kinetics correlates with changes in the folding route for systems at the same temperature, where non-native contacts were shown to be relevant. The transition states of the two systems with and without crowders are similar. In the case of SH3, there are differences in the structuring of two strands, which may be associated with the increase in its folding rate, in addition to the destabilization of the denatured ensemble. The present study also detected a crossover in the thermodynamic stability behavior, previously observed experimentally and theoretically. As the temperature increases, crowders change from destabilizing to stabilizing agents.
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Affiliation(s)
- Vinícius G Contessoto
- Department of Physics, Institute of Biosciences, Letters and Exact Sciences, São Paulo State University, São José do Rio Preto 15054-000, Brazil
| | - Paulo H B Ferreira
- Laboratório de Biofísica Teórica, Departamento de Física, Instituto de Ciências Exatas, Naturais e Educação, Universidade Federal do Triângulo Mineiro, Uberaba 38064-200, Brazil
| | - Jorge Chahine
- Department of Physics, Institute of Biosciences, Letters and Exact Sciences, São Paulo State University, São José do Rio Preto 15054-000, Brazil
| | - Vitor B P Leite
- Department of Physics, Institute of Biosciences, Letters and Exact Sciences, São Paulo State University, São José do Rio Preto 15054-000, Brazil
| | - Ronaldo J Oliveira
- Laboratório de Biofísica Teórica, Departamento de Física, Instituto de Ciências Exatas, Naturais e Educação, Universidade Federal do Triângulo Mineiro, Uberaba 38064-200, Brazil
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14
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TAR RNA Mediated Folding of a Single-Arginine-Mutant HIV-1 Tat Protein within HeLa Cells Experiencing Intracellular Crowding. Int J Mol Sci 2021; 22:ijms22189998. [PMID: 34576162 PMCID: PMC8468913 DOI: 10.3390/ijms22189998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Revised: 09/03/2021] [Accepted: 09/11/2021] [Indexed: 11/17/2022] Open
Abstract
The various effects of native protein folding on the stability and folding rate of intrinsically disordered proteins (IDPs) in crowded intracellular environments are important in biomedicine. Although most studies on protein folding have been conducted in vitro, providing valuable insights, studies on protein folding in crowded intracellular environments are scarce. This study aimed to explore the effects of intracellular molecular crowding on the folding of mutant transactivator HIV-1 Tat based on intracellular interactions, including TAR RNA, as proof of the previously reported chaperna-RNA concept. Considering that the Tat-TAR RNA motif binds RNA, we assessed the po tential function of TAR RNA as a chaperna for the refolding of R52Tat, a mutant in which the argi nine (R) residues at R52 have been replaced with alanine (A) by site-directed mutagenesis. We mon itored Tat-EGFP and Tat folding in HeLa cells via time-lapse fluorescence microscopy and biolayer interferometry using EGFP fusion as an indicator for folding status. These results show that the refolding of R52A Tat was stimulated well at a 0.3 μM TAR RNA concentration; wild-type Tat refolding was essentially abolished because of a reduction in the affinity for TAR RNA at that con centration. The folding and refolding of R52Tat were mainly promoted upon stimulation with TAR RNA. Our findings provide novel insights into the therapeutic potential of chaperna-mediated fold ing through the examination of as-yet-unexplored RNA-mediated protein folding as well as viral genetic variants that modulate viral evolutionary linkages for viral diseases inside a crowded intra cellular environment.
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15
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Li J, Hou C, Ma X, Guo S, Zhang H, Shi L, Liao C, Zheng B, Ye L, Yang L, He X. Entropy-Enthalpy Compensations Fold Proteins in Precise Ways. Int J Mol Sci 2021; 22:9653. [PMID: 34502559 PMCID: PMC8431812 DOI: 10.3390/ijms22179653] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 08/27/2021] [Accepted: 08/30/2021] [Indexed: 12/16/2022] Open
Abstract
Exploring the protein-folding problem has been a longstanding challenge in molecular biology and biophysics. Intramolecular hydrogen (H)-bonds play an extremely important role in stabilizing protein structures. To form these intramolecular H-bonds, nascent unfolded polypeptide chains need to escape from hydrogen bonding with surrounding polar water molecules under the solution conditions that require entropy-enthalpy compensations, according to the Gibbs free energy equation and the change in enthalpy. Here, by analyzing the spatial layout of the side-chains of amino acid residues in experimentally determined protein structures, we reveal a protein-folding mechanism based on the entropy-enthalpy compensations that initially driven by laterally hydrophobic collapse among the side-chains of adjacent residues in the sequences of unfolded protein chains. This hydrophobic collapse promotes the formation of the H-bonds within the polypeptide backbone structures through the entropy-enthalpy compensation mechanism, enabling secondary structures and tertiary structures to fold reproducibly following explicit physical folding codes and forces. The temperature dependence of protein folding is thus attributed to the environment dependence of the conformational Gibbs free energy equation. The folding codes and forces in the amino acid sequence that dictate the formation of β-strands and α-helices can be deciphered with great accuracy through evaluation of the hydrophobic interactions among neighboring side-chains of an unfolded polypeptide from a β-strand-like thermodynamic metastable state. The folding of protein quaternary structures is found to be guided by the entropy-enthalpy compensations in between the docking sites of protein subunits according to the Gibbs free energy equation that is verified by bioinformatics analyses of a dozen structures of dimers. Protein folding is therefore guided by multistage entropy-enthalpy compensations of the system of polypeptide chains and water molecules under the solution conditions.
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Affiliation(s)
- Jiacheng Li
- National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, Center for Composite Materials and Structures, Harbin Institute of Technology, Harbin 150080, China; (J.L.); (X.M.); (S.G.); (H.Z.); (L.S.)
| | - Chengyu Hou
- School of Electronics and Information Engineering, Harbin Institute of Technology, Harbin 150080, China; (C.H.); (C.L.)
| | - Xiaoliang Ma
- National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, Center for Composite Materials and Structures, Harbin Institute of Technology, Harbin 150080, China; (J.L.); (X.M.); (S.G.); (H.Z.); (L.S.)
| | - Shuai Guo
- National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, Center for Composite Materials and Structures, Harbin Institute of Technology, Harbin 150080, China; (J.L.); (X.M.); (S.G.); (H.Z.); (L.S.)
| | - Hongchi Zhang
- National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, Center for Composite Materials and Structures, Harbin Institute of Technology, Harbin 150080, China; (J.L.); (X.M.); (S.G.); (H.Z.); (L.S.)
| | - Liping Shi
- National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, Center for Composite Materials and Structures, Harbin Institute of Technology, Harbin 150080, China; (J.L.); (X.M.); (S.G.); (H.Z.); (L.S.)
| | - Chenchen Liao
- School of Electronics and Information Engineering, Harbin Institute of Technology, Harbin 150080, China; (C.H.); (C.L.)
| | - Bing Zheng
- Key Laboratory of Functional Inorganic Material Chemistry (Ministry of Education), School of Chemistry and Materials Science, Heilongjiang University, Harbin 150001, China;
| | - Lin Ye
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW 2006, Australia;
| | - Lin Yang
- National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, Center for Composite Materials and Structures, Harbin Institute of Technology, Harbin 150080, China; (J.L.); (X.M.); (S.G.); (H.Z.); (L.S.)
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, NSW 2006, Australia;
| | - Xiaodong He
- National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, Center for Composite Materials and Structures, Harbin Institute of Technology, Harbin 150080, China; (J.L.); (X.M.); (S.G.); (H.Z.); (L.S.)
- Shenzhen STRONG Advanced Materials Research Institute Co., Ltd., Shenzhen 518035, China
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16
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Horvath I, Kumar R, Wittung-Stafshede P. Macromolecular crowding modulates α-synuclein amyloid fiber growth. Biophys J 2021; 120:3374-3381. [PMID: 34242594 PMCID: PMC8391083 DOI: 10.1016/j.bpj.2021.06.032] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 05/31/2021] [Accepted: 06/28/2021] [Indexed: 11/18/2022] Open
Abstract
The crowdedness of living cells, hundreds of milligrams per milliliter of macromolecules, may affect protein folding, function, and misfolding. Still, such processes are most often studied in dilute solutions in vitro. To assess consequences of the in vivo milieu, we here investigated the effects of macromolecular crowding on the amyloid fiber formation reaction of α-synuclein, the amyloidogenic protein in Parkinson's disease. For this, we performed spectroscopic experiments probing individual steps of the reaction as a function of the macromolecular crowding agent Ficoll70, which is an inert sucrose-based polymer that provides excluded-volume effects. The experiments were performed at neutral pH at quiescent conditions to avoid artifacts due to shaking and glass beads (typical conditions for α-synuclein), using amyloid fiber seeds to initiate reactions. We find that both primary nucleation and fiber elongation steps during α-synuclein amyloid formation are accelerated by the presence of 140 and 280 mg/mL Ficoll70. Moreover, in the presence of Ficoll70 at neutral pH, secondary nucleation appears favored, resulting in faster overall α-synuclein amyloid formation. In contrast, sucrose, a small-molecule osmolyte and building block of Ficoll70, slowed down α-synuclein amyloid formation. The ability of cell environments to modulate reaction kinetics to a large extent, such as severalfold faster individual steps in α-synuclein amyloid formation, is an important consideration for biochemical reactions in living systems.
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Affiliation(s)
- Istvan Horvath
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Ranjeet Kumar
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Pernilla Wittung-Stafshede
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden.
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17
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Guihur A, Fauvet B, Finka A, Quadroni M, Goloubinoff P. Quantitative proteomic analysis to capture the role of heat-accumulated proteins in moss plant acquired thermotolerance. PLANT, CELL & ENVIRONMENT 2021; 44:2117-2133. [PMID: 33314263 PMCID: PMC8359368 DOI: 10.1111/pce.13975] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 12/03/2020] [Accepted: 12/03/2020] [Indexed: 05/08/2023]
Abstract
At dawn of a scorching summer day, land plants must anticipate upcoming extreme midday temperatures by timely establishing molecular defences that can keep heat-labile membranes and proteins functional. A gradual morning pre-exposure to increasing sub-damaging temperatures induces heat-shock proteins (HSPs) that are central to the onset of plant acquired thermotolerance (AT). To gain knowledge on the mechanisms of AT in the model land plant Physcomitrium patens, we used label-free LC-MS/MS proteomics to quantify the accumulated and depleted proteins before and following a mild heat-priming treatment. High protein crowding is thought to promote protein aggregation, whereas molecular chaperones prevent and actively revert aggregation. Yet, we found that heat priming (HP) did not accumulate HSP chaperones in chloroplasts, although protein crowding was six times higher than in the cytosol. In contrast, several HSP20s strongly accumulated in the cytosol, yet contributing merely 4% of the net mass increase of heat-accumulated proteins. This is in poor concordance with their presumed role at preventing the aggregation of heat-labile proteins. The data suggests that under mild HP unlikely to affect protein stability. Accumulating HSP20s leading to AT, regulate the activity of rare and specific signalling proteins, thereby preventing cell death under noxious heat stress.
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Affiliation(s)
- Anthony Guihur
- Department of Plant Molecular Biology, Faculty of Biology and MedicineUniversity of LausanneLausanneSwitzerland
| | - Bruno Fauvet
- Department of Plant Molecular Biology, Faculty of Biology and MedicineUniversity of LausanneLausanneSwitzerland
| | - Andrija Finka
- Department of Ecology, Agronomy and AquacultureUniversity of ZadarZadarCroatia
| | | | - Pierre Goloubinoff
- Department of Plant Molecular Biology, Faculty of Biology and MedicineUniversity of LausanneLausanneSwitzerland
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18
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It is time to crowd your cell culture media - Physicochemical considerations with biological consequences. Biomaterials 2021; 275:120943. [PMID: 34139505 DOI: 10.1016/j.biomaterials.2021.120943] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Revised: 05/24/2021] [Accepted: 05/29/2021] [Indexed: 12/12/2022]
Abstract
In vivo, the interior and exterior of cells is populated by various macromolecules that create an extremely crowded milieu. Yet again, in vitro eukaryotic cell culture is conducted in dilute culture media that hardly imitate the native tissue density. Herein, the concept of macromolecular crowding is discussed in both intracellular and extracellular context. Particular emphasis is given on how the physicochemical properties of the crowding molecules govern and determine kinetics, equilibria and mechanism of action of biochemical and biological reactions, processes and functions. It is evidenced that we are still at the beginning of appreciating, let alone effectively implementing, the potential of macromolecular crowding in permanently differentiated and stem cell culture systems.
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19
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Zong Y, Xu SM, Shi W, Lu C. Oriented arrangement of simple monomers enabled by confinement: towards living supramolecular polymerization. Nat Commun 2021; 12:2596. [PMID: 33972542 PMCID: PMC8110532 DOI: 10.1038/s41467-021-22827-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Accepted: 03/25/2021] [Indexed: 11/24/2022] Open
Abstract
The living supramolecular polymerization technique provides an exciting research avenue. However, in comparison with the thermodynamic spontaneous nucleation, using simple monomers to realize living supramolecular polymerization is hardly possible from an energy principle. This is because the activation barrier of kinetically trapped simple monomer (nucleation step) is insufficiently high to control the kinetics of subsequent elongation. Here, with the benefit of the confinement from the layered double hydroxide (LDH) nanomaterial, various simple monomers, (such as benzene, naphthalene and pyrene derivatives) successfully form living supramolecular polymer (LSP) with length control and narrow dispersity. The degree of polymerization can reach ~6000. Kinetics studies reveal LDH overcomes a huge energy barrier to inhibit undesired spontaneous nucleation of monomers and disassembly of metastable states. The universality of this strategy will usher exploration into other multifunctional molecules and promote the development of functional LSP. Using simple monomers in living supramolecular polymerization is difficult due to energy principles. Here the authors use confinement from a layered double hydroxide nanomaterial to successfully polymerise several simple monomers with length control and narrow dispersity.
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Affiliation(s)
- Yingtong Zong
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing, P. R. China
| | - Si-Min Xu
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing, P. R. China
| | - Wenying Shi
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing, P. R. China.
| | - Chao Lu
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing, P. R. China.
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20
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Iwakawa N, Morimoto D, Walinda E, Leeb S, Shirakawa M, Danielsson J, Sugase K. Transient Diffusive Interactions with a Protein Crowder Affect Aggregation Processes of Superoxide Dismutase 1 β-Barrel. J Phys Chem B 2021; 125:2521-2532. [PMID: 33657322 DOI: 10.1021/acs.jpcb.0c11162] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Aggregate formation of superoxide dismutase 1 (SOD1) inside motor neurons is known as a major factor in onset of amyotrophic lateral sclerosis. The thermodynamic stability of the SOD1 β-barrel has been shown to decrease in crowded environments such as inside a cell, but it remains unclear how the thermodynamics of crowding-induced protein destabilization relate to SOD1 aggregation. Here we have examined the effects of a protein crowder, lysozyme, on fibril aggregate formation of the SOD1 β-barrel. We found that aggregate formation of SOD1 is decelerated even in mildly crowded solutions. Intriguingly, transient diffusive interactions with lysozyme do not significantly affect the static structure of the SOD1 β-barrel but stabilize an alternative excited "invisible" state. The net effect of crowding is to favor species off the aggregation pathway, thereby explaining the decelerated aggregation in the crowded environment. Our observations suggest that the intracellular environment may have a similar negative (inhibitory) effect on fibril formation of other amyloidogenic proteins in living cells. Deciphering how crowded intracellular environments affect aggregation and fibril formation of such disease-associated proteins will probably become central in understanding the exact role of aggregation in the etiology of these enigmatic diseases.
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Affiliation(s)
- Naoto Iwakawa
- Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Kyoto-Daigaku Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Daichi Morimoto
- Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Kyoto-Daigaku Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Erik Walinda
- Department of Molecular and Cellular Physiology, Graduate School of Medicine, Kyoto University, Yoshida Konoe-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Sarah Leeb
- Department of Biochemistry and Biophysics, Arrhenius Laboratories of Natural Sciences, Stockholm University, 106 91 Stockholm, Sweden
| | - Masahiro Shirakawa
- Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Kyoto-Daigaku Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Jens Danielsson
- Department of Biochemistry and Biophysics, Arrhenius Laboratories of Natural Sciences, Stockholm University, 106 91 Stockholm, Sweden
| | - Kenji Sugase
- Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Kyoto-Daigaku Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
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21
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KhudaBukhsh WR, Kang HW, Kenah E, Rempała GA. Incorporating age and delay into models for biophysical systems. Phys Biol 2021; 18:015002. [PMID: 33075757 DOI: 10.1088/1478-3975/abc2ab] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
In many biological systems, chemical reactions or changes in a physical state are assumed to occur instantaneously. For describing the dynamics of those systems, Markov models that require exponentially distributed inter-event times have been used widely. However, some biophysical processes such as gene transcription and translation are known to have a significant gap between the initiation and the completion of the processes, which renders the usual assumption of exponential distribution untenable. In this paper, we consider relaxing this assumption by incorporating age-dependent random time delays (distributed according to a given probability distribution) into the system dynamics. We do so by constructing a measure-valued Markov process on a more abstract state space, which allows us to keep track of the 'ages' of molecules participating in a chemical reaction. We study the large-volume limit of such age-structured systems. We show that, when appropriately scaled, the stochastic system can be approximated by a system of partial differential equations (PDEs) in the large-volume limit, as opposed to ordinary differential equations (ODEs) in the classical theory. We show how the limiting PDE system can be used for the purpose of further model reductions and for devising efficient simulation algorithms. In order to describe the ideas, we use a simple transcription process as a running example. We, however, note that the methods developed in this paper apply to a wide class of biophysical systems.
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Affiliation(s)
- Wasiur R KhudaBukhsh
- Mathematical Biosciences Institute and the College of Public Health, The Ohio State University, 1735 Neil Avenue, Columbus OH 43210, United States of America
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Naresh V, Lee N. A Review on Biosensors and Recent Development of Nanostructured Materials-Enabled Biosensors. SENSORS (BASEL, SWITZERLAND) 2021; 21:1109. [PMID: 33562639 PMCID: PMC7915135 DOI: 10.3390/s21041109] [Citation(s) in RCA: 363] [Impact Index Per Article: 121.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 02/01/2021] [Accepted: 02/02/2021] [Indexed: 12/18/2022]
Abstract
A biosensor is an integrated receptor-transducer device, which can convert a biological response into an electrical signal. The design and development of biosensors have taken a center stage for researchers or scientists in the recent decade owing to the wide range of biosensor applications, such as health care and disease diagnosis, environmental monitoring, water and food quality monitoring, and drug delivery. The main challenges involved in the biosensor progress are (i) the efficient capturing of biorecognition signals and the transformation of these signals into electrochemical, electrical, optical, gravimetric, or acoustic signals (transduction process), (ii) enhancing transducer performance i.e., increasing sensitivity, shorter response time, reproducibility, and low detection limits even to detect individual molecules, and (iii) miniaturization of the biosensing devices using micro-and nano-fabrication technologies. Those challenges can be met through the integration of sensing technology with nanomaterials, which range from zero- to three-dimensional, possessing a high surface-to-volume ratio, good conductivities, shock-bearing abilities, and color tunability. Nanomaterials (NMs) employed in the fabrication and nanobiosensors include nanoparticles (NPs) (high stability and high carrier capacity), nanowires (NWs) and nanorods (NRs) (capable of high detection sensitivity), carbon nanotubes (CNTs) (large surface area, high electrical and thermal conductivity), and quantum dots (QDs) (color tunability). Furthermore, these nanomaterials can themselves act as transduction elements. This review summarizes the evolution of biosensors, the types of biosensors based on their receptors, transducers, and modern approaches employed in biosensors using nanomaterials such as NPs (e.g., noble metal NPs and metal oxide NPs), NWs, NRs, CNTs, QDs, and dendrimers and their recent advancement in biosensing technology with the expansion of nanotechnology.
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Affiliation(s)
- Varnakavi. Naresh
- School of Advanced Materials Engineering, Kookmin University, Seoul 02707, Korea
| | - Nohyun Lee
- School of Advanced Materials Engineering, Kookmin University, Seoul 02707, Korea
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23
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Response to crowded conditions reveals compact nucleus for amyloid formation of folded protein. QRB DISCOVERY 2021. [PMID: 37529678 PMCID: PMC10392690 DOI: 10.1017/qrd.2020.17] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Abstract
Although the consequences of the crowded cell environments may affect protein folding, function and misfolding reactions, these processes are often studied in dilute solutions in vitro. We here used biophysical experiments to investigate the amyloid fibril formation process of the fish protein apo-β-parvalbumin in solvent conditions that mimic steric and solvation aspects of the in vivo milieu. Apo-β-parvalbumin is a folded protein that readily adopts an amyloid state via a nucleation–elongation mechanism. Aggregation experiments in the presence of macromolecular crowding agents (probing excluded volume, entropic effects) as well as small molecule osmolytes (probing solvation, enthalpic effects) revealed that both types of agents accelerate overall amyloid formation, but the elongation step was faster with macromolecular crowding agents but slower in the presence of osmolytes. The observations can be explained by the steric effects of excluded volume favoring assembled states and that amyloid nucleation does not involve monomer unfolding. In contrast, the solvation effects due to osmolyte presence promote nucleation but not elongation. Therefore, the amyloid-competent nuclei must be compact with less osmolytes excluded from the surface than either the folded monomers or amyloid fibers. We conclude that, in contrast to other amyloidogenic folded proteins, amyloid formation of apo-β-parvalbumin is accelerated by crowded cell-like conditions due to a nucleation process that does not involve large-scale protein unfolding.
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24
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Welte H, Kovermann M. Insights into Protein Stability in Cell Lysate by 19 F NMR Spectroscopy. Chembiochem 2020; 21:3575-3579. [PMID: 32786103 PMCID: PMC7756264 DOI: 10.1002/cbic.202000413] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 07/27/2020] [Indexed: 02/03/2023]
Abstract
In living organisms, protein folding and function take place in an inhomogeneous, highly crowded environment possessing a concentration of diverse macromolecules of up to 400 g/L. It has been shown that the intracellular environment has a pronounced effect on the stability, dynamics and function of the protein under study, and has for this reason to be considered. However, most protein studies neglect the presence of these macromolecules. Consequently, we probe here the overall thermodynamic stability of cold shock protein B from Bacillus subtilis (BsCspB) in cell lysate. We found that an increase in cell lysate concentration causes a monotonic increase in the thermodynamic stability of BsCspB. This result strongly underlines the importance of considering the biological environment when inherent protein parameters are quantitatively determined. Moreover, we demonstrate that targeted application of 19 F NMR spectroscopy operates as an ideal tool for protein studies performed in complex cellular surroundings.
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Affiliation(s)
- Hannah Welte
- Department of ChemistryUniversity KonstanzResearch School Chemical Biology (KoRS-CB)Universitätsstrasse 1078457KonstanzGermany
| | - Michael Kovermann
- Department of ChemistryUniversity KonstanzResearch School Chemical Biology (KoRS-CB)Universitätsstrasse 1078457KonstanzGermany
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25
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Ma Q, Song Y, Sun W, Cao J, Yuan H, Wang X, Sun Y, Shum HC. Cell-Inspired All-Aqueous Microfluidics: From Intracellular Liquid-Liquid Phase Separation toward Advanced Biomaterials. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2020; 7:1903359. [PMID: 32274317 PMCID: PMC7141073 DOI: 10.1002/advs.201903359] [Citation(s) in RCA: 84] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2019] [Revised: 01/06/2020] [Indexed: 05/24/2023]
Abstract
Living cells have evolved over billions of years to develop structural and functional complexity with numerous intracellular compartments that are formed due to liquid-liquid phase separation (LLPS). Discovery of the amazing and vital roles of cells in life has sparked tremendous efforts to investigate and replicate the intracellular LLPS. Among them, all-aqueous emulsions are a minimalistic liquid model that recapitulates the structural and functional features of membraneless organelles and protocells. Here, an emerging all-aqueous microfluidic technology derived from micrometer-scaled manipulation of LLPS is presented; the technology enables the state-of-art design of advanced biomaterials with exquisite structural proficiency and diversified biological functions. Moreover, a variety of emerging biomedical applications, including encapsulation and delivery of bioactive gradients, fabrication of artificial membraneless organelles, as well as printing and assembly of predesigned cell patterns and living tissues, are inspired by their cellular counterparts. Finally, the challenges and perspectives for further advancing the cell-inspired all-aqueous microfluidics toward a more powerful and versatile platform are discussed, particularly regarding new opportunities in multidisciplinary fundamental research and biomedical applications.
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Affiliation(s)
- Qingming Ma
- Department of PharmaceuticsSchool of PharmacyQingdao UniversityQingdao266021China
| | - Yang Song
- Wallace H Coulter Department of Biomedical EngineeringGeorgia Institute of Technology & Emory School of MedicineAtlantaGA30332USA
| | - Wentao Sun
- Center for Basic Medical ResearchTEDA International Cardiovascular HospitalChinese Academy of Medical Sciences & Peking Union Medical CollegeTianjin300457China
| | - Jie Cao
- Department of PharmaceuticsSchool of PharmacyQingdao UniversityQingdao266021China
| | - Hao Yuan
- Institute of Applied MechanicsNational Taiwan UniversityTaipei10617Taiwan
| | - Xinyu Wang
- Institute of Thermal Science and TechnologyShandong UniversityJinan250061China
| | - Yong Sun
- Department of PharmaceuticsSchool of PharmacyQingdao UniversityQingdao266021China
| | - Ho Cheung Shum
- Department of Mechanical EngineeringUniversity of Hong KongPokfulam RoadHong Kong
- HKU‐Shenzhen Institute of Research and Innovation (HKU‐SIRI)Shenzhen518000China
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Wang Y, Zhang L, He Z, Deng J, Zhang Z, Liu L, Ye W, Liu S. Tunicamycin induces ER stress and inhibits tumorigenesis of head and neck cancer cells by inhibiting N-glycosylation. Am J Transl Res 2020; 12:541-550. [PMID: 32194902 PMCID: PMC7061826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2019] [Accepted: 01/06/2020] [Indexed: 06/10/2023]
Abstract
Glycosylation plays an important role in the genesis of various cancers. The inhibition of glycosylation disturbs the protein folding machinery, causing the accumulation of unfolded proteins in the cell endoplasmic reticulum (ER) and inducing ER stress. Tunicamycin (TM) is an inhibitor of glycosylation that has shown marked antitumor activity. In this study, we investigated the effect of TM on the tumorigenesis of head and neck cancer cells. The effects of TM on cell proliferation, colony formation and tumorsphere formation in vitro and tumorigenicity in vivo were investigated in head and neck cancer cells. ER stress was determined by the evaluation of PERK, PDI, IRE1-α, BIP, Ero1-Lα and calnexin expression using western blotting and immunofluorescence. We found that TM inhibited colony formation and tumorsphere formation of head and neck cancer cells in vitro and suppressed tumor growth in vivo. After incubation with TM, the expression of the cancer stem cell markers CD44 and Bmi-1 was reduced, and the expression of the ER stress markers BIP, Ero1-Lα and calnexin was elevated. Moreover, the EGFR signaling pathway was inhibited, and nonglycosylated EGFR degradation was accelerated with TM treatment. Our results suggest that inhibition of glycosylation by TM may be a novel treatment strategy for use with HNSCC patients.
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Affiliation(s)
- Yang Wang
- Department of Oral and Maxillofacial-Head and Neck Oncology, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of MedicineShanghai, China
- Laboratory of Oral Microbiota and Systemic Diseases, Shanghai Ninth People’s Hospital, College of Stomatology, Shanghai Jiao Tong University School of MedicineShanghai, China
- National Clinical Research Center for Oral Diseases, Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of StomatologyShanghai, China
| | - Ling Zhang
- Department of Oral and Maxillofacial-Head and Neck Oncology, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of MedicineShanghai, China
- National Clinical Research Center for Oral Diseases, Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of StomatologyShanghai, China
| | - Zhiyan He
- Laboratory of Oral Microbiota and Systemic Diseases, Shanghai Ninth People’s Hospital, College of Stomatology, Shanghai Jiao Tong University School of MedicineShanghai, China
- National Clinical Research Center for Oral Diseases, Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of StomatologyShanghai, China
| | - Jiong Deng
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Minister of Education, Shanghai Jiao Tong University School of MedicineShanghai, China
| | - Zhiyuan Zhang
- Department of Oral and Maxillofacial-Head and Neck Oncology, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of MedicineShanghai, China
- Laboratory of Oral Microbiota and Systemic Diseases, Shanghai Ninth People’s Hospital, College of Stomatology, Shanghai Jiao Tong University School of MedicineShanghai, China
- National Clinical Research Center for Oral Diseases, Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of StomatologyShanghai, China
| | - Liu Liu
- Department of Oral and Maxillofacial-Head and Neck Oncology, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of MedicineShanghai, China
- National Clinical Research Center for Oral Diseases, Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of StomatologyShanghai, China
| | - Weimin Ye
- Department of Oral and Maxillofacial-Head and Neck Oncology, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of MedicineShanghai, China
- National Clinical Research Center for Oral Diseases, Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of StomatologyShanghai, China
| | - Shuli Liu
- Department of Oral and Maxillofacial-Head and Neck Oncology, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University School of MedicineShanghai, China
- Laboratory of Oral Microbiota and Systemic Diseases, Shanghai Ninth People’s Hospital, College of Stomatology, Shanghai Jiao Tong University School of MedicineShanghai, China
- National Clinical Research Center for Oral Diseases, Shanghai Key Laboratory of Stomatology & Shanghai Research Institute of StomatologyShanghai, China
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Chu X, Suo Z, Wang J. Confinement and Crowding Effects on Folding of a Multidomain Y-Family DNA Polymerase. J Chem Theory Comput 2020; 16:1319-1332. [PMID: 31972079 PMCID: PMC7258223 DOI: 10.1021/acs.jctc.9b01146] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Proteins in vivo endure highly various interactions from the luxuriant surrounding macromolecular cosolutes. Confinement and macromolecular crowding are the two major effects that should be considered while comparing the results of protein dynamics from in vitro to in vivo. However, efforts have been largely focused on single domain protein folding up to now, and the quantifications of the in vivo effects in terms of confinements and crowders on modulating the structure and dynamics as well as the physical understanding of the underlying mechanisms on multidomain protein folding are still challenging. Here we developed a topology-based model to investigate folding of a multidomain Y-family DNA polymerase (DPO4) within spherical confined space and in the presence of repulsive and attractive crowders. We uncovered that the entropic component of the thermodynamic driving force led by confinements and repulsive crowders increases the stability of folded states relative to the folding intermediates and unfolded states, while the enthalpic component of the thermodynamic driving force led by attractive crowders gives rise to the opposite effects with less stability. We found that the shapes of DPO4 conformations influenced by the confinements and the crowders are quite different even when only the entropic component of the thermodynamic driving force is considered. We uncovered that under all in vivo conditions, the folding cooperativity of DPO4 decreases compared to that in bulk. We showed that the loss of folding cooperativity can promote the sequential domain-wise folding, which was widely found in cotranslational multidomain protein folding, and effectively prohibit the backtracking led by topological frustrations during multidomain protein folding processes.
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Affiliation(s)
- Xiakun Chu
- Department of Chemistry, State University of New York at Stony Brook, Stony Brook, New York 11794, United States
| | - Zucai Suo
- Department of Biomedical Sciences, College of Medicine, Florida State University, Tallahassee, Florida 32306, United States
| | - Jin Wang
- Department of Chemistry, State University of New York at Stony Brook, Stony Brook, New York 11794, United States
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Bagchi A. Latest trends in structure based drug design with protein targets. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2019; 121:1-23. [PMID: 32312418 DOI: 10.1016/bs.apcsb.2019.11.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Structure based drug designing is an important endeavor in the field of structural bioinformatics. Previously the entire process was dependent on the wet-lab experiments to build libraries of ligand molecules. And the molecules used to be tested to determine their binding efficacies with protein target. However, the entire process is very lengthy and above all highly expensive. With the advent of supercomputers and increasing computational powers, the search process for finding suitable ligand molecules against target proteins have become more streamlined and cost-effective. Now the entire ligand search process is performed in-silico with the help of the techniques of virtual screening, molecular docking simulations and molecular dynamics studies. In the present chapter, a brief overview of the computational techniques involved in structure based drug designing is presented with a special emphasis on the thermodynamic principles behind the molecular interactions.
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Affiliation(s)
- Angshuman Bagchi
- Department of Biochemistry and Biophysics, University of Kalyani, Kalyani, West Bengal, India
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29
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Kwon S, Sung BJ. Heterogeneous kinetics of the loop formation of a single polymer chain in crowded and disordered media. Phys Rev E 2019; 100:042501. [PMID: 31770886 DOI: 10.1103/physreve.100.042501] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Indexed: 11/06/2022]
Abstract
The cytoplasmic volume of cells is occupied and crowded by a variety of macromolecules, such as proteins and cytoskeleton structures. Such diverse macromolecules make the cell cytoplasm not only structurally heterogeneous but also dynamically heterogeneous: Some macromolecules may diffuse freely inside cell cytoplasm at certain timescales while others hardly diffuse. Studies on the effects of the dynamic heterogeneity on reaction kinetics have been limited even though the effects of the crowdedness and structural heterogeneity were investigated extensively. In this study, we employ a simple model of mixtures of mobile and immobile matrix particles, tune the degree of dynamic heterogeneity by changing the fraction of immobile matrix particles, and investigate reaction kinetics in such heterogeneous media. We employ the loop formation of a single polymer chain as a model reaction and perform Langevin dynamics simulations. We find that the free-energy barrier of the loop formation is decreased as the systems become more crowded with matrix particles. But the free-energy barrier is not sensitive to the dynamic heterogeneity. As dynamic heterogeneity increases with an increase in the fraction of immobile matrix particles, however, the diffusivity of the system decreases significantly. The decrease in the diffusion (due to the dynamic heterogeneity) and the decrease in the free-energy barrier (due to the crowdedness) lead together to a complicated trend of the loop formation kinetics. As the volume fraction of immobile matrix particles reaches a critical value at the percolation transition, the reaction kinetics becomes significantly heterogeneous and the survival probability distribution of the chain loop formation becomes stretched-exponential. We also illustrate that the heterogeneous reaction rate near the percolation transition relates closely to the structures of local pores in which the polymer is located.
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Affiliation(s)
- Seulki Kwon
- Department of Chemistry, Sogang University, Seoul 04107, Republic of Korea
| | - Bong June Sung
- Department of Chemistry, Sogang University, Seoul 04107, Republic of Korea
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30
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Chakravarty AK, Smejkal T, Itakura AK, Garcia DM, Jarosz DF. A Non-amyloid Prion Particle that Activates a Heritable Gene Expression Program. Mol Cell 2019; 77:251-265.e9. [PMID: 31757755 PMCID: PMC6980676 DOI: 10.1016/j.molcel.2019.10.028] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 08/29/2019] [Accepted: 10/17/2019] [Indexed: 11/16/2022]
Abstract
Spatiotemporal gene regulation is often driven by RNA-binding proteins that harbor long intrinsically disordered regions in addition to folded RNA-binding domains. We report that the disordered region of the evolutionarily ancient developmental regulator Vts1/Smaug drives self-assembly into gel-like condensates. These proteinaceous particles are not composed of amyloid, yet they are infectious, allowing them to act as a protein-based epigenetic element: a prion [SMAUG+]. In contrast to many amyloid prions, condensation of Vts1 enhances its function in mRNA decay, and its self-assembly properties are conserved over large evolutionary distances. Yeast cells harboring [SMAUG+] downregulate a coherent network of mRNAs and exhibit improved growth under nutrient limitation. Vts1 condensates formed from purified protein can transform naive cells to acquire [SMAUG+]. Our data establish that non-amyloid self-assembly of RNA-binding proteins can drive a form of epigenetics beyond the chromosome, instilling adaptive gene expression programs that are heritable over long biological timescales.
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Affiliation(s)
- Anupam K Chakravarty
- Department of Chemical and Systems Biology, Stanford University, 269 Campus Drive, Stanford, CA 94305, USA
| | - Tina Smejkal
- Department of Chemical and Systems Biology, Stanford University, 269 Campus Drive, Stanford, CA 94305, USA
| | - Alan K Itakura
- Department of Biology, Stanford University, 269 Campus Drive, Stanford, CA 94305, USA
| | - David M Garcia
- Department of Chemical and Systems Biology, Stanford University, 269 Campus Drive, Stanford, CA 94305, USA
| | - Daniel F Jarosz
- Department of Chemical and Systems Biology, Stanford University, 269 Campus Drive, Stanford, CA 94305, USA; Department of Developmental Biology, Stanford University, 269 Campus Drive, Stanford, CA 94305, USA.
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31
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Physicochemical considerations for bottom-up synthetic biology. Emerg Top Life Sci 2019; 3:445-458. [PMID: 33523159 PMCID: PMC7289010 DOI: 10.1042/etls20190017] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 08/05/2019] [Accepted: 08/07/2019] [Indexed: 12/18/2022]
Abstract
The bottom-up construction of synthetic cells from molecular components is arguably one of the most challenging areas of research in the life sciences. We review the impact of confining biological systems in synthetic vesicles. Complex cell-like systems require control of the internal pH, ionic strength, (macro)molecular crowding, redox state and metabolic energy conservation. These physicochemical parameters influence protein activity and need to be maintained within limits to ensure the system remains in steady-state. We present the physicochemical considerations for building synthetic cells with dimensions ranging from the smallest prokaryotes to eukaryotic cells.
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32
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Guin D, Gruebele M. Weak Chemical Interactions That Drive Protein Evolution: Crowding, Sticking, and Quinary Structure in Folding and Function. Chem Rev 2019; 119:10691-10717. [PMID: 31356058 DOI: 10.1021/acs.chemrev.8b00753] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
In recent years, better instrumentation and greater computing power have enabled the imaging of elusive biomolecule dynamics in cells, driving many advances in understanding the chemical organization of biological systems. The focus of this Review is on interactions in the cell that affect both biomolecular stability and function and modulate them. The same protein or nucleic acid can behave differently depending on the time in the cell cycle, the location in a specific compartment, or the stresses acting on the cell. We describe in detail the crowding, sticking, and quinary structure in the cell and the current methods to quantify them both in vitro and in vivo. Finally, we discuss protein evolution in the cell in light of current biophysical evidence. We describe the factors that drive protein evolution and shape protein interaction networks. These interactions can significantly affect the free energy, ΔG, of marginally stable and low-population proteins and, due to epistasis, direct the evolutionary pathways in an organism. We finally conclude by providing an outlook on experiments to come and the possibility of collaborative evolutionary biology and biophysical efforts.
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Affiliation(s)
- Drishti Guin
- Department of Chemistry , University of Illinois , Urbana , Illinois 61801 , United States
| | - Martin Gruebele
- Department of Chemistry , University of Illinois , Urbana , Illinois 61801 , United States.,Department of Physics , University of Illinois , Urbana , Illinois 61801 , United States.,Center for Biophysics and Quantitative Biology , University of Illinois , Urbana , Illinois 61801 , United States
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33
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Sustained activity and stability of lysozyme in aqueous ionic liquid solutions containing carboxymethylcellulose and polyethylene glycol. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2019.01.052] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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35
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Transgenic zebrafish models reveal distinct molecular mechanisms for cataract-linked αA-crystallin mutants. PLoS One 2018; 13:e0207540. [PMID: 30475834 PMCID: PMC6261105 DOI: 10.1371/journal.pone.0207540] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 11/01/2018] [Indexed: 11/19/2022] Open
Abstract
Mutations in the small heat shock proteins α-crystallins have been linked to autosomal dominant cataracts in humans. Extensive studies in vitro have revealed a spectrum of alterations to the structure and function of these proteins including shifts in the size of the oligomer, modulation of subunit exchange and modification of their affinity to client proteins. Although mouse models of these mutants were instrumental in identifying changes in cellular proliferation and lens development, a direct comparative analysis of their effects on lens proteostasis has not been performed. Here, we have transgenically expressed cataract-linked mutants of αA- and αB-crystallin in the zebrafish lens to dissect the underlying molecular changes that contribute to the loss of lens optical properties. Zebrafish lines expressing these mutants displayed a range of morphological lens defects. Phenotype penetrance and severity were dependent on the mutation even in fish lines lacking endogenous α-crystallin. The mechanistic origins of these differences were investigated by the transgenic co-expression of a destabilized human γD-crystallin mutant. We found that the R49C but not the R116C mutant of αA-crystallin drove aggregation of γD-crystallin, although both mutants have similar affinity to client proteins in vitro. Our working model attributes these differences to the propensity of R49C, located in the buried N-terminal domain of αA-crystallin, to disulfide crosslinking as previously demonstrated in vitro. Our findings complement and extend previous work in mouse models and emphasize the need of investigating chaperone/client protein interactions in appropriate cellular context.
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36
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Isogai Y, Imamura H, Nakae S, Sumi T, Takahashi KI, Nakagawa T, Tsuneshige A, Shirai T. Tracing whale myoglobin evolution by resurrecting ancient proteins. Sci Rep 2018; 8:16883. [PMID: 30442991 PMCID: PMC6237822 DOI: 10.1038/s41598-018-34984-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 10/29/2018] [Indexed: 11/24/2022] Open
Abstract
Extant cetaceans, such as sperm whale, acquired the great ability to dive into the ocean depths during the evolution from their terrestrial ancestor that lived about 50 million years ago. Myoglobin (Mb) is highly concentrated in the myocytes of diving animals, in comparison with those of land animals, and is thought to play a crucial role in their adaptation as the molecular aqualung. Here, we resurrected ancestral whale Mbs, which are from the common ancestor between toothed and baleen whales (Basilosaurus), and from a further common quadrupedal ancestor between whale and hippopotamus (Pakicetus). The experimental and theoretical analyses demonstrated that whale Mb adopted two distinguished strategies to increase the protein concentration in vivo along the evolutionary history of deep sea adaptation; gaining precipitant tolerance in the early phase of the evolution, and increase of folding stability in the late phase.
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Affiliation(s)
- Yasuhiro Isogai
- Department of Pharmaceutical Engineering, Toyama Prefectural University, Imizu, Toyama, 939-0398, Japan.
| | - Hiroshi Imamura
- Department of Applied Chemistry, College of Life Sciences, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu, Shiga, 525-8577, Japan
| | - Setsu Nakae
- Department of Computer Bioscience, Nagahama Institute of Bio-Science and Technology, 1266 Tamura-Cho, Nagahama, Shiga, 526-0829, Japan
| | - Tomonari Sumi
- Research Institute for Interdisciplinary Science, Okayama University, 3-1-1 Tsushima-Naka, Kita-ku, Okayama, 700-8530, Japan
| | - Ken-Ichi Takahashi
- Department of Computer Bioscience, Nagahama Institute of Bio-Science and Technology, 1266 Tamura-Cho, Nagahama, Shiga, 526-0829, Japan
| | - Taro Nakagawa
- Department of Computer Bioscience, Nagahama Institute of Bio-Science and Technology, 1266 Tamura-Cho, Nagahama, Shiga, 526-0829, Japan
| | - Antonio Tsuneshige
- Department of Frontier Bioscience and Research Center for Micro-Nano Technology, Hosei University, Koganei, Tokyo, Japan
| | - Tsuyoshi Shirai
- Department of Computer Bioscience, Nagahama Institute of Bio-Science and Technology, 1266 Tamura-Cho, Nagahama, Shiga, 526-0829, Japan.
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Tsarpali V, Dailianis S. [omim][BF 4]-mediated toxicity in mussel hemocytes includes its interaction with cellular membrane proteins. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2018; 203:88-94. [PMID: 30099324 DOI: 10.1016/j.aquatox.2018.08.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2018] [Revised: 07/13/2018] [Accepted: 08/05/2018] [Indexed: 06/08/2023]
Abstract
The current study is based on the increasing demand for the assessment of ionic liquid (IL)-mediated aquatic toxicity. Specifically, although a lot of studies have been performed so far, investigating IL-mediated adverse effects on numerous aquatic organisms, little is known about their mode of action. Given that the use of in vitro models is considered as a reliable tool for determining the mediated biological effects, the modulation of specific biochemical pathways and the onset of various forms of damage with great precision and reproducibility, mixed primary cultures of mussel Mytilus galloprovincialis hemocytes were used for investigating whether 1-octyl-3-methylimidazolium tetrafluoroborate ([omim][BF4]) mediated toxicity is related to its interaction with cellular membrane proteins. Specifically, [omim][BF4]-mediated cytotoxic, oxidative and genotoxic effects were investigated in mussel hemocytes before and after pre-treatment of cells with non-toxic concentration of guanidine hydrochloride (1 mM GndHCl). The results showed that [omim][BF4] at concentrations ranging from 0.7 to 1.75 μM can induce cytotoxic (almost <50% reduction of cell viability), oxidative (increased levels of O2•- production and lipid peroxidation by-products) and genotoxic (increased levels of DNA damage) effects, while cells pre-treated with 1 mM GndHCl showed a significant attenuation of IL's toxic potency in all cases. According to the latter, the current study showed that [omim][BF4]-mediated toxicity could be related not only to its well-known interaction with membrane lipid bilayers, but also to its interference with membrane proteins. Using GndHCl, a chaotropic agent that disrupts the hydrogen bonding network and the stability of membrane proteins via its interference with the intramolecular interactions mediated by non-covalent forces on cellular membranes, it was firstly shown that altering the membrane integrity as well as the native state of cellular membrane proteins, by weakening the hydrophobic effect, could attenuate the possible interaction of [omim][BF4] with cellular membranes and the concomitant induction of protein-based intracellular processes, commonly linked with the induction of severe cellular damage.
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Affiliation(s)
- Vasiliki Tsarpali
- Section of Animal Biology, Department of Biology, Faculty of Sciences, University of Patras, GR-26 500 Patras, Greece
| | - Stefanos Dailianis
- Section of Animal Biology, Department of Biology, Faculty of Sciences, University of Patras, GR-26 500 Patras, Greece.
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38
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Davis WJ, Denton AR. Influence of solvent quality on conformations of crowded polymers. J Chem Phys 2018; 149:124901. [PMID: 30278673 DOI: 10.1063/1.5043434] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
The structure and function of polymers in confined environments, e.g., biopolymers in the cytoplasm of a cell, are strongly affected by macromolecular crowding. To explore the influence of solvent quality on conformations of crowded polymers, we model polymers as penetrable ellipsoids, whose shape fluctuations are governed by the statistics of self-avoiding walks, appropriate for a polymer in a good solvent. Within this coarse-grained model, we perform Monte Carlo simulations of mixtures of polymers and hard-nanosphere crowders, including trial changes in polymer size and shape. Penetration of polymers by crowders is incorporated via a free energy cost predicted by polymer field theory. To analyze the impact of crowding on polymer conformations in different solvents, we compute the average polymer shape distributions, radius of gyration, volume, and asphericity over ranges of the polymer-to-crowder size ratio and crowder volume fraction. The simulation results are accurately predicted by a free-volume theory of polymer crowding. Comparison of results for polymers in good and theta solvents indicates that excluded-volume interactions between polymer segments significantly affect crowding, especially in the limit of crowders much smaller than polymers. Our approach may help to motivate future experimental studies of polymers in crowded environments, with possible relevance for drug delivery and gene therapy.
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Affiliation(s)
- Wyatt J Davis
- Department of Physics, North Dakota State University, Fargo, North Dakota 58108-6050, USA
| | - Alan R Denton
- Department of Physics, North Dakota State University, Fargo, North Dakota 58108-6050, USA
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39
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Hata Y, Sawada T, Serizawa T. Macromolecular crowding for materials-directed controlled self-assembly. J Mater Chem B 2018; 6:6344-6359. [PMID: 32254643 DOI: 10.1039/c8tb02201a] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Macromolecular crowding refers to intracellular environments where various macromolecules, including proteins and nucleic acids, are present at high total concentrations. Its influence on biological processes has been investigated using a highly concentrated in vitro solution of water-soluble polymers as a model. Studies have revealed significant effects of macromolecular crowding on the thermodynamic equilibria and dynamics of biomolecular self-assembly in vivo. Recently, macromolecular crowding has attracted materials scientists, especially those in bio-related areas, as a tool to control molecular/colloidal self-assembly. Macromolecular crowding has been exploited to control the structure of supramolecular materials, assemble nanomaterials, and improve the performance of polymeric materials. Furthermore, nanostructured materials have been shown to be an interesting alternative to water-soluble polymers for creating crowded environments for controlled self-assembly. In this review article, we summarize recent progress in research on macromolecular crowding for controlled self-assembly in bio-related materials chemistry.
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Affiliation(s)
- Yuuki Hata
- Department of Chemical Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, 2-12-1-H121 Ookayama, Meguro-ku, Tokyo 152-8550, Japan.
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40
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Liu W, Fu L, Wang Z, Sohrabpour Z, Li X, Liu Y, Wang HF, Yan ECY. Two dimensional crowding effects on protein folding at interfaces observed by chiral vibrational sum frequency generation spectroscopy. Phys Chem Chem Phys 2018; 20:22421-22426. [PMID: 30159555 DOI: 10.1039/c7cp07061f] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2023]
Abstract
The crowding effect is prevalent in cellular environments due to high concentrations of biomacromolecules. It can alter the structures and dynamics of proteins and thus impact protein functions. The crowding effect is important not only in 3-dimensional cytoplasm but also for a 2-dimensional (2D) cell surface due to the presence of membrane proteins and glycosylation of membrane proteins and phospholipids. These proteins and phospholipids - with limited translational degrees of freedom along the surface normal - are confined in 2D space. Although the crowding effect at interfaces has been studied by adding crowding agents to bulk solution, the 2D crowding effect remains largely unexplored. This is mostly due to challenges in controlling 2D crowding and synergistic use of physical methods for in situ protein characterization. To address these challenges, we applied chiral vibrational sum frequency generation (SFG) spectroscopy to probe the sp1 zinc finger (ZnF), a 31-amino acid protein, folding into a β-hairpin/α-helix (ββα) motif upon binding to Zn2+. We anchored ZnF at the air/water interface via covalent linkage of ZnF to palmitic acid and controlled 2D crowding by introducing neutral lipid as a spacer. We obtained chiral amide I SFG spectra upon addition of Zn2+ and/or spacer lipid. The chiral SFG spectra show that interfacial crowding in the absence of spacer lipid hinders ZnF from folding into the ββα structure even in the presence of Zn2+. The results establish a paradigm for future quantitative, systematic studies of interfacial crowding effects.
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Affiliation(s)
- Wei Liu
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520, USA.
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41
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Chen E, Esquerra RM, Meléndez PA, Chandrasekaran SS, Kliger DS. Microviscosity in E. coli Cells from Time-Resolved Linear Dichroism Measurements. J Phys Chem B 2018; 122:11381-11389. [PMID: 30118225 DOI: 10.1021/acs.jpcb.8b07362] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
A protein's folding or function depends on its mobility through the viscous environment that is defined by the presence of macromolecules throughout the cell. The relevant parameter for this mobility is microviscosity-the viscosity on a time and distance scale that is important for protein folding/function movements. A quasi-null, ultrasensitive time-resolved linear dichroism (TRLD) spectroscopy is proving to be a useful tool for measurements of viscosity on this scale, with previous in vitro studies reporting on the microviscosities of crowded environments mimicked by high concentrations of different macromolecules. This study reports the microviscosity experienced by myoglobin in the E. coli cell's heterogeneous cytoplasm by using TRLD to measure rotational diffusion times. The results show that photolyzed deoxyMb ensembles randomize through environment-dependent rotational diffusion with a lifetime of 34 ± 6 ns. This value corresponds to a microviscosity of 2.82 ± 0.42 cP, which is consistent with previous reports of cytoplasmic viscosity in E. coli. The results of these TRLD studies in E. coli (1) provide a measurement of myoglobin mobility in the cytoplasm, (2) taken together with in vitro TRLD studies yield new insights into the nature of the cytoplasmic environment in cells, and (3) demonstrate the feasibility of TRLD as a probe of intracellular viscosity.
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Affiliation(s)
- Eefei Chen
- Department of Chemistry and Biochemistry , University of California , Santa Cruz , California 95064 , United States
| | - Raymond M Esquerra
- Department of Chemistry and Biochemistry , San Francisco State University , San Francisco , California 94132 , United States
| | - Philipp A Meléndez
- Department of Chemistry and Biochemistry , San Francisco State University , San Francisco , California 94132 , United States
| | - Sita S Chandrasekaran
- Department of Chemistry and Biochemistry , San Francisco State University , San Francisco , California 94132 , United States
| | - David S Kliger
- Department of Chemistry and Biochemistry , University of California , Santa Cruz , California 95064 , United States
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Mahynski NA, Jiao S, Hatch HW, Blanco MA, Shen VK. Predicting structural properties of fluids by thermodynamic extrapolation. J Chem Phys 2018; 148:194105. [PMID: 30307179 PMCID: PMC6183068 DOI: 10.1063/1.5026493] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We describe a methodology for extrapolating the structural properties of multicomponent fluids from one thermodynamic state to another. These properties generally include features of a system that may be computed from an individual configuration such as radial distribution functions, cluster size distributions, or a polymer's radius of gyration. This approach is based on the principle of using fluctuations in a system's extensive thermodynamic variables, such as energy, to construct an appropriate Taylor series expansion for these structural properties in terms of intensive conjugate variables, such as temperature. Thus, one may extrapolate these properties from one state to another when the series is truncated to some finite order. We demonstrate this extrapolation for simple and coarse-grained fluids in both the canonical and grand canonical ensembles, in terms of both temperatures and the chemical potentials of different components. The results show that this method is able to reasonably approximate structural properties of such fluids over a broad range of conditions. Consequently, this methodology may be employed to increase the computational efficiency of molecular simulations used to measure the structural properties of certain fluid systems, especially those used in high-throughput or data-driven investigations.
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Affiliation(s)
- Nathan A. Mahynski
- Chemical Sciences Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8320, USA
| | - Sally Jiao
- Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544, USA
| | - Harold W. Hatch
- Chemical Sciences Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8320, USA
| | - Marco A. Blanco
- Chemical Sciences Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8320, USA
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, Maryland 20850, USA
| | - Vincent K. Shen
- Chemical Sciences Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8320, USA
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Abstract
Cytochrome c (Cyt c) was rapidly oxidized by molecular oxygen in the presence, but not absence of PEG. The redox potential of heme c was determined by the potentiometric titration to be +236 ± 3 mV in the absence of PEG, which was negatively shifted to +200 ± 4 mV in the presence of PEG. The underlying the rapid oxidation was explored by examining the structural changes in Cyt c in the presence of PEG using UV-visible absorption, circular dichroism, resonance Raman, and fluorescence spectroscopies. These spectroscopic analyses suggested that heme oxidation was induced by a modest tertiary structural change accompanied by a slight shift in the heme position (<1.0 Å) rather than by partial denaturation, as is observed in the presence of cardiolipin. The near-infrared spectra showed that PEG induced dehydration from Cyt c, which triggered heme displacement. The primary dehydration site was estimated to be around surface-exposed hydrophobic residues near the heme center: Ile81 and Val83. These findings and our previous studies, which showed that hydrated water molecules around Ile81 and Val83 are expelled when Cyt c forms a complex with CcO, proposed that dehydration of these residues is functionally significant to electron transfer from Cyt c to CcO.
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Krainer G, Hartmann A, Anandamurugan A, Gracia P, Keller S, Schlierf M. Ultrafast Protein Folding in Membrane-Mimetic Environments. J Mol Biol 2018; 430:554-564. [DOI: 10.1016/j.jmb.2017.10.031] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 10/12/2017] [Accepted: 10/27/2017] [Indexed: 01/06/2023]
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Caccia S, Suffritti C, Carzaniga T, Berardelli R, Berra S, Martorana V, Fra A, Drouet C, Cicardi M. Intermittent C1-Inhibitor Deficiency Associated with Recessive Inheritance: Functional and Structural Insight. Sci Rep 2018; 8:977. [PMID: 29343682 PMCID: PMC5772639 DOI: 10.1038/s41598-017-16667-w] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 11/15/2017] [Indexed: 12/13/2022] Open
Abstract
C1-inhibitor is a serine protease inhibitor (serpin) controlling complement and contact system activation. Gene mutations result in reduced C1-inhibitor functional plasma level causing hereditary angioedema, a life-threatening disorder. Despite a stable defect, the clinical expression of hereditary angioedema is unpredictable, and the molecular mechanism underlying this variability remains undisclosed. Here we report functional and structural studies on the Arg378Cys C1-inhibitor mutant found in a patient presenting reduced C1-inhibitor levels, episodically undergoing normalization. Expression studies resulted in a drop in mutant C1-innhibitor secretion compared to wild-type. Notwithstanding, the purified proteins had similar features. Thermal denaturation experiments showed a comparable denaturation profile, but the mutant thermal stability decays when tested in conditions reproducing intracellular crowding.Our findings suggest that once correctly folded, the Arg378Cys C1-inhibitor is secreted as an active, although quite unstable, monomer. However, it could bear a folding defect, occasionally promoting protein oligomerization and interfering with the secretion process, thus accounting for its plasma level variability. This defect is exacerbated by the nature of the mutation since the acquired cysteine leads to the formation of non-functional homodimers through inter-molecular disulphide bonding. All the proposed phenomena could be modulated by specific environmental conditions, rendering this mutant exceptionally vulnerable to mild stress.
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Affiliation(s)
- Sonia Caccia
- "L. Sacco" Department of Biomedical and Clinical Sciences, University of Milan, via GB Grassi 74, 20157, Milan, Italy.
| | - Chiara Suffritti
- "L. Sacco" Department of Biomedical and Clinical Sciences, University of Milan, via GB Grassi 74, 20157, Milan, Italy
| | - Thomas Carzaniga
- "L. Sacco" Department of Biomedical and Clinical Sciences, University of Milan, via GB Grassi 74, 20157, Milan, Italy
| | - Romina Berardelli
- Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Silvia Berra
- "L. Sacco" Department of Biomedical and Clinical Sciences, University of Milan, via GB Grassi 74, 20157, Milan, Italy
| | - Vincenzo Martorana
- Institute of Biophysics, National Research Council of Italy, Palermo, Italy
| | - Annamaria Fra
- Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Christian Drouet
- GREPI EA7408, Universite Grenoble Alpes, and CREAK, CHU Grenoble, Grenoble, France
| | - Marco Cicardi
- "L. Sacco" Department of Biomedical and Clinical Sciences, University of Milan, via GB Grassi 74, 20157, Milan, Italy
- Luigi Sacco Hospital, Milan, Italy
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Carlisle C, Prill K, Pilgrim D. Chaperones and the Proteasome System: Regulating the Construction and Demolition of Striated Muscle. Int J Mol Sci 2017; 19:E32. [PMID: 29271938 PMCID: PMC5795982 DOI: 10.3390/ijms19010032] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2017] [Revised: 11/28/2017] [Accepted: 12/18/2017] [Indexed: 12/21/2022] Open
Abstract
Protein folding factors (chaperones) are required for many diverse cellular functions. In striated muscle, chaperones are required for contractile protein function, as well as the larger scale assembly of the basic unit of muscle, the sarcomere. The sarcomere is complex and composed of hundreds of proteins and the number of proteins and processes recognized to be regulated by chaperones has increased dramatically over the past decade. Research in the past ten years has begun to discover and characterize the chaperones involved in the assembly of the sarcomere at a rapid rate. Because of the dynamic nature of muscle, wear and tear damage is inevitable. Several systems, including chaperones and the ubiquitin proteasome system (UPS), have evolved to regulate protein turnover. Much of our knowledge of muscle development focuses on the formation of the sarcomere but recent work has begun to elucidate the requirement and role of chaperones and the UPS in sarcomere maintenance and disease. This review will cover the roles of chaperones in sarcomere assembly, the importance of chaperone homeostasis and the cooperation of chaperones and the UPS in sarcomere integrity and disease.
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Affiliation(s)
- Casey Carlisle
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada.
| | - Kendal Prill
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada.
| | - Dave Pilgrim
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada.
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Shamsi TN, Athar T, Parveen R, Fatima S. A review on protein misfolding, aggregation and strategies to prevent related ailments. Int J Biol Macromol 2017; 105:993-1000. [PMID: 28743576 DOI: 10.1016/j.ijbiomac.2017.07.116] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2017] [Revised: 07/13/2017] [Accepted: 07/18/2017] [Indexed: 01/28/2023]
Abstract
This review aims to highlight the fundamental mechanism of protein misfolding leading to protein aggregation and associated diseases. It also aims to anticipate novel therapeutic strategies with which to prevent or treat these highly debilitating conditions linked to these pathologies. The failure of a protein to correctly fold de novo or to remain correctly folded can have profound consequences on a living system especially when the cellular quality control processes fail to eliminate the rogue proteins. The core cause of over 20 different human diseases which have now been designated as 'conformational diseases' including neurodegenerative diseases such as Alzheimer's disease (AD), Huntington's disease (HD) and Parkinson's disease (PD) etc. A comprehensive study on protein misfolding, aggregation, and the outcomes of the effects of cytotoxic aggregates will lead to understand the aggregation-mediated cell toxicity and serves as a foundation for future research in development of promising therapies and drugs. This review has also shed light on the mechanism of protein misfolding which leads to its aggregation and hence the neurodegeneration. From these considerations, one could also envisage the possibility that protein aggregation may be exploited by nature to perform specific physiological functions in differing biological contexts.
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Affiliation(s)
- Tooba Naz Shamsi
- Department of Biotechnology, Jamia Millia Islamia, New Delhi 110025, India.
| | - Teeba Athar
- Department of Biotechnology, Jamia Millia Islamia, New Delhi 110025, India.
| | - Romana Parveen
- Department of Biotechnology, Jamia Millia Islamia, New Delhi 110025, India.
| | - Sadaf Fatima
- Department of Biotechnology, Jamia Millia Islamia, New Delhi 110025, India.
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Gorensek-Benitez AH, Smith AE, Stadmiller SS, Perez Goncalves GM, Pielak GJ. Cosolutes, Crowding, and Protein Folding Kinetics. J Phys Chem B 2017; 121:6527-6537. [PMID: 28605189 PMCID: PMC5982521 DOI: 10.1021/acs.jpcb.7b03786] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Long accepted as the most important interaction, recent work shows that steric repulsions alone cannot explain the effects of macromolecular cosolutes on the equilibrium thermodynamics of protein stability. Instead, chemical interactions have been shown to modulate, and even dominate, crowding-induced steric repulsions. Here, we use 19F NMR to examine the effects of small and large cosolutes on the kinetics of protein folding and unfolding using the metastable 7 kDa N-terminal SH3 domain of the Drosophila signaling protein drk (SH3), which folds by a two-state mechanism. The small cosolutes consist of trimethylamine N-oxide and sucrose, which increase equilibrium protein stability, and urea, which destabilizes proteins. The macromolecules comprise the stabilizing sucrose polymer, Ficoll, and the destabilizing globular protein, lysozyme. We assessed the effects of these cosolutes on the differences in free energy between the folded state and the transition state and between the unfolded ensemble and the transition state. We then examined the temperature dependence to assess changes in activation enthalpy and entropy. The enthalpically mediated effects are more complicated than suggested by equilibrium measurements. We also observed enthalpic effects with the supposedly inert sucrose polymer, Ficoll, that arise from its macromolecular nature. Assessment of activation entropies shows important contributions from solvent and cosolute, in addition to the configurational entropy of the protein that, again, cannot be gleaned from equilibrium data. Comparing the effects of Ficoll to those of the more physiologically relevant cosolute lysozyme reveals that synthetic polymers are not appropriate models for understanding the kinetics of protein folding in cells.
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Affiliation(s)
| | - Austin E. Smith
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599, United States
| | - Samantha S. Stadmiller
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599, United States
| | | | - Gary J. Pielak
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599, United States
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, North Carolina 27599, United States
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599, United States
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Carpinteri A, Lacidogna G, Piana G, Bassani A. Terahertz mechanical vibrations in lysozyme: Raman spectroscopy vs modal analysis. J Mol Struct 2017. [DOI: 10.1016/j.molstruc.2017.02.099] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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50
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Abstract
Based on the Shannon's information communication theory, information amount of the entire length of a polymeric macromolecule can be calculated in bits through adding the entropies of each building block. Proteins, DNA and RNA are such macromolecules. When only the building blocks' variation is considered as the source of entropy, there is seemingly lower information in case of the protein if this approach is applied directly on a protein of specific size and the coding sequence size of the mRNA corresponding to the particular length of the protein. This decrease in the information amount seems contradictory but this apparent conflict is resolved by considering the conformational variations in proteins as a new variable in the calculation and balancing the approximated entropy of the coding part of the mRNA and the protein. Probabilities can change therefore we also assigned hypothetical probabilities to the conformational states, which represent the uneven distribution as the time spent in one conformation, providing the probability of the presence in either or one of the possible conformations. Results that are obtained by using hypothetical probabilities are in line with the experimental values of variations in the conformational-state of protein populations. This equalization approach has further biological relevance that it compensates for the degeneracy in the codon usage during protein translation and it leads to the conclusion that the alphabet size for the protein is rather optimal for the proper protein functioning within the thermodynamic milieu of the cell. The findings were also discussed in relation to the codon bias and have implications in relation to the codon evolution concept. Eventually, this work brings the fields of protein structural studies and molecular protein translation processes together with a novel approach.
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Affiliation(s)
- Y Adiguzel
- Biophysics Department, School of Medicine, Istanbul Kemerburgaz University, Istanbul, Turkey.
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