1
|
Workman RJ, Huang CJ, Lynch GC, Pettitt BM. Peptide diffusion in biomolecular condensates. Biophys J 2024; 123:1668-1675. [PMID: 38751116 DOI: 10.1016/j.bpj.2024.05.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 04/22/2024] [Accepted: 05/10/2024] [Indexed: 05/30/2024] Open
Abstract
Diffusion determines the turnover of biomolecules in liquid-liquid phase-separated condensates. We considered the mean square displacement and thus the diffusion constant for simple model systems of peptides GGGGG, GGQGG, and GGVGG in aqueous solutions after phase separation by simulating atomic-level models. These solutions readily separate into aqueous and peptide-rich droplet phases. We noted the effect of the peptides being in a solvated, surface, or droplet state on the peptide's diffusion coefficients. Both sequence and peptide conformational distribution were found to influence diffusion and condensate turnover in these systems, with sequence dominating the magnitude of the differences. We found that the most compact structures for each sequence diffused the fastest in the peptide-rich condensate phase. This model result may have implications for turnover dynamics in signaling systems.
Collapse
Affiliation(s)
- Riley J Workman
- University of Texas Medical Branch, 301 University Boulevard, Galveston, Texas
| | - Caleb J Huang
- University of Texas Medical Branch, 301 University Boulevard, Galveston, Texas
| | - Gillian C Lynch
- University of Texas Medical Branch, 301 University Boulevard, Galveston, Texas
| | | |
Collapse
|
2
|
Yamaguchi T, Chong SH, Yoshida N. Coexistence of two coacervate phases of polyglycine in water suggested by polymer reference interaction site model theory. J Chem Phys 2023; 159:245101. [PMID: 38131487 DOI: 10.1063/5.0185157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2023] [Accepted: 11/30/2023] [Indexed: 12/23/2023] Open
Abstract
Mixing Gibbs energy and phase equilibria of aqueous solutions of polyglycine were studied theoretically by means of polymer reference interaction site model integral equation theory combined with the Gibbs-Duhem method. In addition to the ordinary liquid-liquid phase separation between dilute and concentrated solutions, the theoretical calculation predicted the coexistence of two coacervate phases, namely, the lower- and higher-density coacervates. The relative thermodynamic stabilities of these two phases change with the polymerization degree of polyglycine. The higher-density coacervate phase was rapidly stabilized by increasing the polymer length, and the lower-density phase became metastable at large polymers. The hydrogen bonds between the peptide chains were strengthened, and water was thermodynamically destabilized in the higher-density coacervate. A possible relation with the formation of amyloid fibril within a liquid droplet is also discussed.
Collapse
Affiliation(s)
- Tsuyoshi Yamaguchi
- Graduate School of Engineering, Nagoya University, Chikusa, Nagoya 464-8603, Japan
| | - Song-Ho Chong
- Global Center for Natural Resources Sciences, Faculty of Life Sciences, Kumamoto University, Oe-honmachi 5-1, Chuo-ku, Kumamoto 862-0973, Japan
| | - Norio Yoshida
- Graduate School of Informatics, Nagoya University, Chikusa, Nagoya 464-8601, Japan
| |
Collapse
|
3
|
Skriver K, Theisen FF, Kragelund BB. Conformational entropy in molecular recognition of intrinsically disordered proteins. Curr Opin Struct Biol 2023; 83:102697. [PMID: 37716093 DOI: 10.1016/j.sbi.2023.102697] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 08/12/2023] [Accepted: 08/14/2023] [Indexed: 09/18/2023]
Abstract
Broad conformational ensembles make intrinsically disordered proteins or regions entropically intriguing. Although methodologically challenging and understudied, emerging studies into their changes in conformational entropy (ΔS°conf) upon complex formation have provided both quantitative and qualitative insight. Recent work based on thermodynamics from isothermal titration calorimetry and NMR spectroscopy uncovers an expanded repertoire of regulatory mechanisms, where ΔS°conf plays roles in partner selection, state behavior, functional buffering, allosteric regulation, and drug design. We highlight these mechanisms to display the large entropic reservoir of IDPs for the regulation of molecular communication. We call upon the field to make efforts to contribute to this insight as more studies are needed for forwarding mechanistic decoding of intrinsically disordered proteins and their complexes.
Collapse
Affiliation(s)
- Karen Skriver
- The Linderstrøm Lang Centre for Protein Science, University of Copenhagen, Ole Maaloes Vej 5, DK-2200 Copenhagen N, Denmark; REPIN, University of Copenhagen, Ole Maaloes Vej 5, DK-2200 Copenhagen N, Denmark
| | - Frederik Friis Theisen
- The Linderstrøm Lang Centre for Protein Science, University of Copenhagen, Ole Maaloes Vej 5, DK-2200 Copenhagen N, Denmark; REPIN, University of Copenhagen, Ole Maaloes Vej 5, DK-2200 Copenhagen N, Denmark; Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Ole Maaloes Vej 5, DK-2200 Copenhagen N, Denmark. https://twitter.com/@FrederikTheisen
| | - Birthe B Kragelund
- The Linderstrøm Lang Centre for Protein Science, University of Copenhagen, Ole Maaloes Vej 5, DK-2200 Copenhagen N, Denmark; REPIN, University of Copenhagen, Ole Maaloes Vej 5, DK-2200 Copenhagen N, Denmark; Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Ole Maaloes Vej 5, DK-2200 Copenhagen N, Denmark.
| |
Collapse
|
4
|
Huang C, Pettitt BM. Parameter Dependence of the Solubility Limit for Disodium Phosphate. J Phys Chem B 2023; 127:8690-8696. [PMID: 37788371 PMCID: PMC10913426 DOI: 10.1021/acs.jpcb.3c05343] [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] [Indexed: 10/05/2023]
Abstract
The solubility limit was calculated for supersaturated solutions of disodium phosphate in water as a function of the sodium-oxygen Lennard-Jones radius parameter Rmin. We found that changes in the sodium-oxygen Rmin were clearly exponentially related to the concentration of the solubility limit. Starting from standard force fields more suited to nucleic acids and phospholipids, only relatively small changes were required to achieve the experimentally known solubility limit. Simultaneously, we found that it was possible to achieve the solubility limit and the osmotic pressure with the same model parameters. Based on transferability, the adjusted Rmin parameter can be used to more accurately model phosphorylated proteins.
Collapse
Affiliation(s)
- Caleb Huang
- Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, Texas 77555-0304, United States
| | - B Montgomery Pettitt
- Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, Texas 77555-0304, United States
| |
Collapse
|
5
|
Nam J, Gwon Y. Neuronal biomolecular condensates and their implications in neurodegenerative diseases. Front Aging Neurosci 2023; 15:1145420. [PMID: 37065458 PMCID: PMC10102667 DOI: 10.3389/fnagi.2023.1145420] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 03/01/2023] [Indexed: 04/03/2023] Open
Abstract
Biomolecular condensates are subcellular organizations where functionally related proteins and nucleic acids are assembled through liquid-liquid phase separation, allowing them to develop on a larger scale without a membrane. However, biomolecular condensates are highly vulnerable to disruptions from genetic risks and various factors inside and outside the cell and are strongly implicated in the pathogenesis of many neurodegenerative diseases. In addition to the classical view of the nucleation-polymerization process that triggers the protein aggregation from the misfolded seed, the pathologic transition of biomolecular condensates can also promote the aggregation of proteins found in the deposits of neurodegenerative diseases. Furthermore, it has been suggested that several protein or protein-RNA complexes located in the synapse and along the neuronal process are neuron-specific condensates displaying liquid-like properties. As their compositional and functional modifications play a crucial role in the context of neurodegeneration, further research is needed to fully understand the role of neuronal biomolecular condensates. In this article, we will discuss recent findings that explore the pivotal role of biomolecular condensates in the development of neuronal defects and neurodegeneration.
Collapse
Affiliation(s)
| | - Youngdae Gwon
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea
| |
Collapse
|
6
|
Workman RJ, Gorle S, Pettitt BM. Effects of Conformational Constraint on Peptide Solubility Limits. J Phys Chem B 2022; 126:10510-10518. [PMID: 36450134 DOI: 10.1021/acs.jpcb.2c06458] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
Liquid-liquid phase separation of proteins preferentially involves intrinsically disordered proteins or disordered regions. Understanding the solution chemistry of these phase separations is key to learning how to quantify and manipulate systems that involve such processes. Here, we investigate the effect of cyclization on the liquid-liquid phase separation of short polyglycine peptides. We simulated separate aqueous systems of supersaturated cyclic and linear GGGGG and observed spontaneous liquid-liquid phase separation in each of the solutions. The cyclic GGGGG phase separates less robustly than linear GGGGG and has a higher aqueous solubility, even though linear GGGGG has a more favorable single molecule solvation free energy. The versatile and abundant interpeptide contacts formed by the linear GGGGG stabilize the condensed droplet phase, driving the phase separation in this system. In particular, we find that van der Waals close contact interactions are enriched in the droplet phase as opposed to electrostatic interactions. An analysis of the change in backbone conformational entropy that accompanies the phase transition revealed that cyclic peptides lose significantly less entropy in this process as expected. However, we find that the enhanced interaction enthalpy of linear GGGGG in the droplet phase is enough to compensate for a larger decrease in conformational entropy.
Collapse
Affiliation(s)
- Riley J Workman
- Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, Texas 77555-0304, United States
| | - Suresh Gorle
- Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, Texas 77555-0304, United States
| | - B Montgomery Pettitt
- Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, Texas 77555-0304, United States
| |
Collapse
|
7
|
Multivalent interactions between molecular components involved in fast endophilin mediated endocytosis drive protein phase separation. Nat Commun 2022; 13:5017. [PMID: 36028485 PMCID: PMC9418313 DOI: 10.1038/s41467-022-32529-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 08/03/2022] [Indexed: 11/30/2022] Open
Abstract
A specific group of transmembrane receptors, including the β1-adrenergic receptor (β1-AR), is internalized through a non-clathrin pathway known as Fast Endophilin Mediated Endocytosis (FEME). A key question is: how does the endocytic machinery assemble and how is it modulated by activated receptors during FEME. Here we show that endophilin, a major regulator of FEME, undergoes a phase transition into liquid-like condensates, which facilitates the formation of multi-protein assemblies by enabling the phase partitioning of endophilin binding proteins. The phase transition can be triggered by specific multivalent binding partners of endophilin in the FEME pathway such as the third intracellular loop (TIL) of the β1-AR, and the C-terminal domain of lamellipodin (LPD). Other endocytic accessory proteins can either partition into, or target interfacial regions of, these condensate droplets, and LPD also phase separates with the actin polymerase VASP. On the membrane, TIL promotes protein clustering in the presence of endophilin and LPD C-terminal domain. Our results demonstrate how the multivalent interactions between endophilin, LPD, and TIL regulate protein assembly formation on the membrane, providing mechanistic insights into the priming and initiation steps of FEME. Here the authors show that protein phase separation is a key mechanism in cellular receptor internalization via fast endophilin mediated endocytosis (FEME). Phase separation facilitates multivalent FEME-protein assembly in this clathrin-independent pathway.
Collapse
|
8
|
Arora L, Mukhopadhyay S. Conformational Characteristics and Phase Behavior of Intrinsically Disordered Proteins─Where Physical Chemistry Meets Biology. J Phys Chem B 2022; 126:5137-5139. [PMID: 35860904 DOI: 10.1021/acs.jpcb.2c04017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Lisha Arora
- Centre for Protein Science, Design and Engineering, Indian Institute of Science Education and Research (IISER) Mohali, Sector 81, Mohali, SAS Nagar, Knowledge City, Punjab 140306, India.,Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector 81, Mohali, SAS Nagar, Knowledge City, Punjab 140306, India
| | - Samrat Mukhopadhyay
- Centre for Protein Science, Design and Engineering, Indian Institute of Science Education and Research (IISER) Mohali, Sector 81, Mohali, SAS Nagar, Knowledge City, Punjab 140306, India.,Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector 81, Mohali, SAS Nagar, Knowledge City, Punjab 140306, India.,Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector 81, Mohali, SAS Nagar, Knowledge City, Punjab 140306, India
| |
Collapse
|
9
|
Theisen FF, Staby L, Tidemand FG, O'Shea C, Prestel A, Willemoës M, Kragelund BB, Skriver K. Quantification of Conformational Entropy Unravels Effect of Disordered Flanking Region in Coupled Folding and Binding. J Am Chem Soc 2021; 143:14540-14550. [PMID: 34473923 DOI: 10.1021/jacs.1c04214] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Intrinsic disorder (ID) constitutes a new dimension to the protein structure-function relationship. The ability to undergo conformational changes upon binding is a key property of intrinsically disordered proteins and remains challenging to study using conventional methods. A 1994 paper by R. S. Spolar and M. T. Record presented a thermodynamic approach for estimating changes in conformational entropy based on heat capacity changes, allowing quantification of residues folding upon binding. Here, we adapt the method for studies of intrinsically disordered proteins. We integrate additional data to provide a broader experimental foundation for the underlying relations and, based on >500 protein-protein complexes involving disordered proteins, reassess a key relation between polar and nonpolar surface area changes, previously determined using globular protein folding. We demonstrate the improved suitability of the adapted method to studies of the folded αα-hub domain RST from radical-induced cell death 1, whose interactome is characterized by ID. From extensive thermodynamic data, quantifying the conformational entropy changes upon binding, and comparison to the NMR structure, the adapted method improves accuracy for ID-based studies. Furthermore, we apply the method, in conjunction with NMR, to reveal hitherto undetected effects of interaction-motif context. Thus, inclusion of the disordered context of the DREB2A RST-binding motif induces structuring of the binding motif, resulting in major enthalpy-entropy compensation in the interaction interface. This study, also evaluating additional interactions, demonstrates the strength of the ID-adapted Spolar-Record thermodynamic approach for dissection of structural features of ID-based interactions, easily overlooked in traditional studies, and for translation of these into mechanistic knowledge.
Collapse
Affiliation(s)
| | | | - Frederik Grønbæk Tidemand
- Structural Biophysics, X-ray and Neutron Science, The Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen Ø, Denmark
| | | | | | | | | | | |
Collapse
|