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Han Q, El Mohamad M, Brown S, Zhai J, Rosado CJ, Shen Y, Blanch EW, Drummond CJ, Greaves TL. Small angle X-ray scattering investigation of ionic liquid effect on the aggregation behavior of globular proteins. J Colloid Interface Sci 2023; 648:376-388. [PMID: 37302221 DOI: 10.1016/j.jcis.2023.05.130] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 05/02/2023] [Accepted: 05/18/2023] [Indexed: 06/13/2023]
Abstract
Globular proteins are well-folded model proteins, where ions can substantially influence their structure and aggregation. Ionic liquids (ILs) are salts in the liquid state with versatile ion combinations. Understanding the IL effect on protein behavior remains a major challenge. Here, we employed small angle X-ray scattering to investigate the effect of aqueous ILs on the structure and aggregation of globular proteins, namely, hen egg white lysozyme (Lys), human lysozyme (HLys), myoglobin (Mb), β-lactoglobulin (βLg), trypsin (Tryp) and superfolder green fluorescent protein (sfGFP). The ILs contain ammonium-based cations paired with the mesylate, acetate or nitrate anion. Results showed that only Lys was monomeric, whereas the other proteins formed small or large aggregates in buffer. Solutions with over 17 mol% IL resulted in significant changes in the protein structure and aggregation. The Lys structure was expanded at 1 mol% but compact at 17 mol% with structural changes in loop regions. HLys formed small aggregates, with the IL effect similar to Lys. Mb and βLg mostly had distinct monomer and dimer distributions depending on IL type and IL concentration. Complex aggregation was noted for Tryp and sfGFP. While the anion had the largest ion effect, changing the cation also induced the structural expansion and protein aggregation.
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Affiliation(s)
- Qi Han
- School of Science, STEM College, RMIT University, Melbourne, VIC 3000, Australia.
| | - Mohamad El Mohamad
- School of Science, STEM College, RMIT University, Melbourne, VIC 3000, Australia
| | - Stuart Brown
- School of Science, STEM College, RMIT University, Melbourne, VIC 3000, Australia
| | - Jiali Zhai
- School of Science, STEM College, RMIT University, Melbourne, VIC 3000, Australia
| | - Carlos J Rosado
- Department of Diabetes, Central Clinical School, Monash University, VIC 3004, Australia; Department of Biochemistry, Monash University, VIC 3800, Australia
| | - Yi Shen
- School of Chemical and Biomolecular Engineering, The University of Sydney, Sydney, NSW 2006, Australia; The University of Sydney Nano Institute, The University of Sydney, Sydney, NSW 2006, Australia
| | - Ewan W Blanch
- School of Science, STEM College, RMIT University, Melbourne, VIC 3000, Australia
| | - Calum J Drummond
- School of Science, STEM College, RMIT University, Melbourne, VIC 3000, Australia
| | - Tamar L Greaves
- School of Science, STEM College, RMIT University, Melbourne, VIC 3000, Australia.
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Jussupow A, Lopez A, Baumgart M, Mader SL, Sattler M, Kaila VRI. Extended conformational states dominate the Hsp90 chaperone dynamics. J Biol Chem 2022; 298:102101. [PMID: 35667441 PMCID: PMC9251789 DOI: 10.1016/j.jbc.2022.102101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 05/29/2022] [Accepted: 05/30/2022] [Indexed: 11/16/2022] Open
Abstract
The heat shock protein 90 (Hsp90) is a molecular chaperone central to client protein folding and maturation in eukaryotic cells. During its chaperone cycle, Hsp90 undergoes ATPase-coupled large-scale conformational changes between open and closed states, where the N-terminal and middle domains of the protein form a compact dimerized conformation. However, the molecular principles of the switching motion between the open and closed states remain poorly understood. Here we show by integrating atomistic and coarse-grained molecular simulations with small-angle X-ray scattering experiments and NMR spectroscopy data that Hsp90 exhibits rich conformational dynamics modulated by the charged linker, which connects the N-terminal with the middle domain of the protein. We show that the dissociation of these domains is crucial for the conformational flexibility of the open state, with the separation distance controlled by a β-sheet motif next to the linker region. Taken together, our results suggest that the conformational ensemble of Hsp90 comprises highly extended states, which could be functionally crucial for client processing.
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Affiliation(s)
- Alexander Jussupow
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Abraham Lopez
- Center of Integrated Protein Science, Department Chemie, Technische Universität München Lichtenbergstr. 4, 85747 Garching (Germany); Institute of Structural Biology, Helmholtz Zentrum Mu¨nchen, Ingolstädter Landstrasse 1, Neuherberg 85764, Germany
| | - Mona Baumgart
- Center of Integrated Protein Science, Department Chemie, Technische Universität München Lichtenbergstr. 4, 85747 Garching (Germany)
| | - Sophie L Mader
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Michael Sattler
- Center of Integrated Protein Science, Department Chemie, Technische Universität München Lichtenbergstr. 4, 85747 Garching (Germany); Institute of Structural Biology, Helmholtz Zentrum Mu¨nchen, Ingolstädter Landstrasse 1, Neuherberg 85764, Germany
| | - Ville R I Kaila
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden.
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Metrick CM, Koenigsberg AL, Heldwein EE. Conserved Outer Tegument Component UL11 from Herpes Simplex Virus 1 Is an Intrinsically Disordered, RNA-Binding Protein. mBio 2020; 11:e00810-20. [PMID: 32371601 DOI: 10.1128/mBio.00810-20] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Herpesvirus virions contain a unique tegument layer sandwiched between the capsid and lipid envelope and composed of multiple copies of about two dozen viral proteins. However, little is known about the structure of the tegument or how it is assembled. Here, we show that a conserved tegument protein UL11 from herpes simplex virus 1, a prototypical alphaherpesvirus, is an intrinsically disordered protein that undergoes liquid-liquid phase separation in vitro. Through sequence analysis, we find intrinsically disordered regions of different lengths in all HSV-1 tegument proteins. We hypothesize that intrinsic disorder is a common characteristic of tegument proteins and propose a new model of tegument as a biomolecular condensate. A distinguishing morphological feature of all herpesviruses is the multiprotein tegument layer located between the nucleocapsid and lipid envelope of the virion. Tegument proteins play multiple roles in viral replication, including viral assembly, but we do not yet understand their individual functions or how the tegument is assembled and organized. UL11, the smallest tegument protein, is important for several distinct processes in replication, including efficient virion morphogenesis and cell-cell spread. However, the mechanistic understanding of its role in these and other processes is limited in part by the scant knowledge of its biochemical and structural properties. Here, we report that UL11 from herpes simplex virus 1 (HSV-1) is an intrinsically disordered, conformationally dynamic protein that undergoes liquid-liquid phase separation (LLPS) in vitro. Intrinsic disorder may underlie the ability of UL11 to exert multiple functions and bind multiple partners. Sequence analysis suggests that not only all UL11 homologs but also all HSV-1 tegument proteins contain intrinsically disordered regions of different lengths. The presence of intrinsic disorder, and potentially, the ability to form LLPS, may thus be a common feature of the tegument proteins. We hypothesize that tegument assembly may involve the formation of a biomolecular condensate, driven by the heterogeneous mixture of intrinsically disordered tegument proteins.
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