The role of cluster formation and metastable liquid—liquid phase separation in protein crystallization

2012 ◽  
Vol 159 ◽  
pp. 313 ◽  
Author(s):  
Fajun Zhang ◽  
Felix Roosen-Runge ◽  
Andrea Sauter ◽  
Roland Roth ◽  
Maximilian W. A. Skoda ◽  
...  
Keyword(s):  
Phase Separation ◽  
Liquid Phase ◽  
Protein Crystallization ◽  
Cluster Formation ◽  
Liquid Phase Separation ◽  
Metastable Liquid ◽  
Liquid Liquid Phase Separation

Reentrant condensation, liquid–liquid phase separation and crystallization in protein solutions induced by multivalent metal ions

2014 ◽  
Vol 86 (2) ◽  
pp. 191-202 ◽  
Author(s):  
Fajun Zhang ◽  
Felix Roosen-Runge ◽  
Andrea Sauter ◽  
Marcell Wolf ◽  
Robert M. J. Jacobs ◽  
...  
Keyword(s):  
Phase Separation ◽  
Liquid Phase ◽  
Metal Ions ◽  
Protein Interactions ◽  
Protein Crystallization ◽  
Liquid Phase Separation ◽  
Protein Solutions ◽  
Metastable Liquid ◽  
Multivalent Metal ◽  
Liquid Liquid Phase Separation

Abstract We briefly summarize the recent progress in tuning protein interactions as well as phase behavior in protein solutions using multivalent metal ions. We focus on the influence of control parameters and the mechanism of reentrant condensation, the metastable liquid–liquid phase separation and classical vs. non-classical pathways of protein crystallization.

Protein Crystallization in the Presence of a Metastable Liquid–Liquid Phase Separation

2020 ◽  
Vol 20 (12) ◽  
pp. 7951-7962
Author(s):  
Ralph Maier ◽  
Georg Zocher ◽  
Andrea Sauter ◽  
Stefano Da Vela ◽  
Olga Matsarskaia ◽  
...  
Keyword(s):  
Phase Separation ◽  
Liquid Phase ◽  
Protein Crystallization ◽  
Liquid Phase Separation ◽  
Metastable Liquid ◽  
Liquid Liquid Phase Separation

scholarly journals Deciphering the Role of π-Interactions in Polyelectrolyte Complexes Using Rationally Designed Peptides

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2074
Author(s):  
Sara Tabandeh ◽  
Cristina Elisabeth Lemus ◽  
Lorraine Leon
Keyword(s):  
Hydrogen Bonding ◽  
Phase Separation ◽  
Liquid Phase ◽  
Charge Density ◽  
Secondary Structures ◽  
Liquid Phase Separation ◽  
Polyelectrolyte Complexes ◽  
Π Interactions ◽  
Liquid Liquid Phase Separation

Electrostatic interactions, and specifically π-interactions play a significant role in the liquid-liquid phase separation of proteins and formation of membraneless organelles/or biological condensates. Sequence patterning of peptides allows creating protein-like structures and controlling the chemistry and interactions of the mimetic molecules. A library of oppositely charged polypeptides was designed and synthesized to investigate the role of π-interactions on phase separation and secondary structures of polyelectrolyte complexes. Phenylalanine was chosen as the π-containing residue and was used together with lysine or glutamic acid in the design of positively or negatively charged sequences. The effect of charge density and also the substitution of fluorine on the phenylalanine ring, known to disrupt π-interactions, were investigated. Characterization analysis using MALDI-TOF mass spectroscopy, H NMR, and circular dichroism (CD) confirmed the molecular structure and chiral pattern of peptide sequences. Despite an alternating sequence of chirality previously shown to promote liquid-liquid phase separation, complexes appeared as solid precipitates, suggesting strong interactions between the sequence pairs. The secondary structures of sequence pairs showed the formation of hydrogen-bonded structures with a β-sheet signal in FTIR spectroscopy. The presence of fluorine decreased hydrogen bonding due to its inhibitory effect on π-interactions. π-interactions resulted in enhanced stability of complexes against salt, and higher critical salt concentrations for complexes with more π-containing amino acids. Furthermore, UV-vis spectroscopy showed that sequences containing π-interactions and increased charge density encapsulated a small charged molecule with π-bonds with high efficiency. These findings highlight the interplay between ionic, hydrophobic, hydrogen bonding, and π-interactions in polyelectrolyte complex formation and enhance our understanding of phase separation phenomena in protein-like structures.

scholarly journals Liquid–liquid phase separation in human health and diseases

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Bin Wang ◽  
Lei Zhang ◽  
Tong Dai ◽  
Ziran Qin ◽  
Huasong Lu ◽  
...  
Keyword(s):  
Phase Separation ◽  
Liquid Phase ◽  
Human Health ◽  
Essential Role ◽  
Current Knowledge ◽  
Vital Role ◽  
Liquid Phase Separation ◽  
Eukaryotic Cells ◽  
Liquid Liquid Phase Separation

AbstractEmerging evidence suggests that liquid–liquid phase separation (LLPS) represents a vital and ubiquitous phenomenon underlying the formation of membraneless organelles in eukaryotic cells (also known as biomolecular condensates or droplets). Recent studies have revealed evidences that indicate that LLPS plays a vital role in human health and diseases. In this review, we describe our current understanding of LLPS and summarize its physiological functions. We further describe the role of LLPS in the development of human diseases. Additionally, we review the recently developed methods for studying LLPS. Although LLPS research is in its infancy—but is fast-growing—it is clear that LLPS plays an essential role in the development of pathophysiological conditions. This highlights the need for an overview of the recent advances in the field to translate our current knowledge regarding LLPS into therapeutic discoveries.

scholarly journals Taurine suppresses liquid-liquid phase separation of lysozyme protein

2021 ◽  
Author(s):  
Kanae Tsubotani ◽  
Sayuri Maeyama ◽  
Shigeru Murakami ◽  
Stephen W Schaffer ◽  
Takashi Ito
Keyword(s):  
Phase Separation ◽  
Polyethylene Glycol ◽  
Critical Temperature ◽  
Liquid Phase ◽  
Liquid Phase Separation ◽  
Compatible Osmolyte ◽  
Hen Egg ◽  
Liquid Liquid Phase Separation ◽  
In Cells

AbstractTaurine is a compatible osmolyte that infers stability to proteins. Recent studies have revealed that liquid-liquid phase separation (LLPS) of proteins underlie the formation of membraneless organelles in cells. In the present study, we evaluated the role of taurine on LLPS of hen egg lysozyme. We demonstrated that taurine decreases the turbidity of the polyethylene glycol-induced crowding solution of lysozyme. We also demonstrated that taurine attenuates LLPS-dependent cloudiness of lysozyme solution with 0.5 or 1M NaCl at a critical temperature. Moreover, we observed that taurine inhibits LLPS formation of a heteroprotein mix solution of lysozyme and ovalbumin. These data indicate that taurine can modulate the formation of LLPS of proteins.

scholarly journals Bi-directional protein-protein interactions control liquid-liquid phase separation of PSD-95 and its interaction partners

2021 ◽  
Author(s):  
Nikolaj Riis Christensen ◽  
Christian Parsbæk Pedersen ◽  
Vita Sereikaite ◽  
Jannik Nedergaard Pedersen ◽  
Maria Vistrup-Parry ◽  
...  
Keyword(s):  
Phase Separation ◽  
Liquid Phase ◽  
Protein Interactions ◽  
Postsynaptic Density ◽  
Specific Protein ◽  
Liquid Phase Separation ◽  
Protein Protein Interactions ◽  
New Perspective ◽  
Liquid Liquid Phase Separation

SUMMARYThe organization of the postsynaptic density (PSD), a protein-dense semi-membraneless organelle, is mediated by numerous specific protein-protein interactions (PPIs) which constitute a functional post-synapse. Postsynaptic density protein 95 (PSD-95) interacts with a manifold of proteins, including the C-terminal of transmembrane AMPA receptor (AMAPR) regulatory proteins (TARPs). Here, we uncover the minimal essential peptide responsible for the stargazin (TARP-γ2) mediated liquid-liquid phase separation (LLPS) formation of PSD-95 and other key protein constituents of the PSD. Furthermore, we find that pharmacological inhibitors of PSD-95 can facilitate formation of LLPS. We found that in some cases LLPS formation is dependent on multivalent interactions while in other cases short peptides carrying a high charge are sufficient to promote LLPS in complex systems. This study offers a new perspective on PSD-95 interactions and their role in LLPS formation, while also considering the role of affinity over multivalency in LLPS systems.

scholarly journals Liquid–liquid phase separation of tau protein: The crucial role of electrostatic interactions

2019 ◽  
Vol 294 (29) ◽  
pp. 11054-11059 ◽  
Author(s):  
Solomiia Boyko ◽  
Xu Qi ◽  
Tien-Hao Chen ◽  
Krystyna Surewicz ◽  
Witold K. Surewicz
Keyword(s):  
Phase Separation ◽  
Liquid Phase ◽  
Tau Protein ◽  
Crucial Role ◽  
Electrostatic Interactions ◽  
Liquid Phase Separation ◽  
Liquid Liquid Phase Separation

scholarly journals Liquid–Liquid Phase Separation in Crowded Environments

2020 ◽  
Vol 21 (16) ◽  
pp. 5908 ◽  
Author(s):  
Alain A. M. André ◽  
Evan Spruijt
Keyword(s):  
Phase Separation ◽  
Liquid Phase ◽  
Macromolecular Crowding ◽  
Liquid Phase Separation ◽  
The Impact ◽  
Crowded Environments ◽  
Liquid Liquid Phase Separation ◽  
In Cells

Biomolecular condensates play a key role in organizing cellular fluids such as the cytoplasm and nucleoplasm. Most of these non-membranous organelles show liquid-like properties both in cells and when studied in vitro through liquid–liquid phase separation (LLPS) of purified proteins. In general, LLPS of proteins is known to be sensitive to variations in pH, temperature and ionic strength, but the role of crowding remains underappreciated. Several decades of research have shown that macromolecular crowding can have profound effects on protein interactions, folding and aggregation, and it must, by extension, also impact LLPS. However, the precise role of crowding in LLPS is far from trivial, as most condensate components have a disordered nature and exhibit multiple weak attractive interactions. Here, we discuss which factors determine the scope of LLPS in crowded environments, and we review the evidence for the impact of macromolecular crowding on phase boundaries, partitioning behavior and condensate properties. Based on a comparison of both in vivo and in vitro LLPS studies, we propose that phase separation in cells does not solely rely on attractive interactions, but shows important similarities to segregative phase separation.

Charge-controlled metastable liquid–liquid phase separation in protein solutions as a universal pathway towards crystallization

Soft Matter ◽  
2012 ◽  
Vol 8 (5) ◽  
pp. 1313-1316 ◽  
Author(s):  
Fajun Zhang ◽  
Roland Roth ◽  
Marcell Wolf ◽  
Felix Roosen-Runge ◽  
Maximilian W. A. Skoda ◽  
...  
Keyword(s):  
Phase Separation ◽  
Liquid Phase ◽  
Liquid Phase Separation ◽  
Protein Solutions ◽  
Metastable Liquid ◽  
Liquid Liquid Phase Separation
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