Coexistence of two coacervate phases of polyglycine in water suggested by polymer reference interaction site model theory

The Journal of Chemical Physics, Journal Year: 2023, Volume and Issue: 159(24)

Published: Dec. 22, 2023

Mixing Gibbs energy and phase equilibria of aqueous solutions polyglycine were studied theoretically by means polymer reference interaction site model integral equation theory combined with the Gibbs-Duhem method. In addition to ordinary liquid-liquid separation between dilute concentrated solutions, theoretical calculation predicted coexistence two coacervate phases, namely, lower- higher-density coacervates. The relative thermodynamic stabilities these phases change polymerization degree polyglycine. was rapidly stabilized increasing length, lower-density became metastable at large polymers. hydrogen bonds peptide chains strengthened, water thermodynamically destabilized in coacervate. A possible relation formation amyloid fibril within a liquid droplet is also discussed.

Language: Английский

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Amyloid Morphology is Encoded in H-bonds and Electrostatics Interactions Ruling Protein Phase Separation

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: Jan. 11, 2024

Abstract Ion-protein interactions regulate biological processes and are the basis of key strategies modulating protein phase diagrams stability in drug development. Here, we report mechanisms by which H-bonds electrostatic ion-protein systems determine separation amyloid formation. Using microscopy, small-angle X-ray scattering, circular dichroism atomistic molecular dynamics (MD) simulations, found that anions specifically interacting with insulin induced neutralising charge forming H-bond bridges between molecules. The same interaction was responsible for an enhanced conformational resistance to oligomerisation. Under aggregation conditions, anion-protein translated into activation a coalescence process, leading amyloid-like microparticles. This reaction is alternative conformationally-driven pathways, giving rise elongated fibrils occurs absence preferential binding. Our findings depict unifying scenario common dictated both at low temperatures occurrence pronounced heterogeneity morphology high temperatures, similar what has previously been reported crystal growth.

Language: Английский

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A reaction-diffusion model captures the essence of liquid-liquid phase separation

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: April 30, 2024

In this work we propose the formulation of a continuum model for liquid-liquid phase separation (LLPS) using reaction diffusion framework. We consider well mixed liquid consisting three phases, dense droplet phase, dilute and remaining part to be solvent phase. As key feature, includes both spatial temporal aspects free energy functional between that is physically motivated by reference molecular simulation. The exhaustive numerical simulations captures dynamical formation droplets existence LLPS. time progresses, simulation reveal smaller gradually vanish, single undergoes continuous growth until it reaches stable size. predicts extent diffusivity as their mutual interaction would modulate kinetics formation. Finally show introduction fluctuation in accelerate process.

Language: Английский

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Screening of liquid–liquid phase separation conditions for proteins with a mixed solution kit of biomacromolecular crowding agents

Journal of Molecular Liquids, Journal Year: 2024, Volume and Issue: 406, P. 125038 - 125038

Published: May 19, 2024

Language: Английский

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Oligomerization-Mediated Phase-Separation in the Nucleoid-Associated Sensory Protein H-NS is Controlled by Ambient Cues

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: Aug. 11, 2024

ABSTRACT H-NS, a nucleoid-associated protein (NAP) from enterobacteria, regulates gene expression by dynamically transducing environmental cues to conformational assembly and DNA binding. In this work, we show that H-NS Escherichia coli , which can assemble into octameric tetrameric oligomerization states, forms spontaneous micron-sized liquid-like condensates with at sub-physiological concentrations in vitro . The heterotypic are metastable 298 K, partially solubilizing time, while still retaining their properties. display UCST-like phase behavior higher temperatures, but large decrease droplet-assembly propensities 310 K also ionic strength. Condensate formation be tuned cyclic manner between the extent of reversibility determined incubation highlighting strong hysteresis. An engineered phospho-mimetic variant (Y61E) is dimeric only weakly binds DNA, unable form condensates. Y61E mutant solubilizes pre-formed few minutes nearly an order magnitude speed-up droplet dissolution relative demonstrating rapid molecular transport dilute condensed phases. Our results establish intrinsically tied not binding its phase-separation tendencies, showcasing regulatable programmable nature formed archetypal NAP via multiple lifetimes.

Language: Английский

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Oligomerization‐mediated phase separation in the nucleoid‐associated sensory protein H‐NS is controlled by ambient cues

Protein Science, Journal Year: 2024, Volume and Issue: 34(1)

Published: Dec. 11, 2024

H-NS, a nucleoid-associated protein (NAP) from enterobacteria, regulates gene expression by dynamically transducing environmental cues to conformational assembly and DNA binding. In this work, we show that H-NS Escherichia coli, which can assemble into octameric tetrameric oligomerization states, forms spontaneous micron-sized liquid-like condensates with at sub-physiological concentrations in vitro. The heterotypic are metastable 298 K, partially solubilizing time, while still retaining their properties. display UCST-like phase behavior higher temperatures, but large decrease droplet-assembly propensities 310 K ionic strength. Condensate formation be tuned cyclic manner between the extent of reversibility determined incubation highlighting strong hysteresis. An engineered phospho-mimetic variant (Y61E), is dimeric only weakly binds DNA, unable form condensates. Y61E mutant solubilizes pre-formed few minutes nearly an order magnitude speed-up droplet dissolution relative demonstrating rapid molecular transport dilute condensed phases. Our results establish intrinsically tied not binding also its phase-separation tendencies, showcasing regulatable programmable nature formed archetypal NAP via multiple lifetimes.

Language: Английский

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Insulin Amyloid Morphology is Encoded in H-bonds and Electrostatics Interactions Ruling Protein Phase Separation

Journal of Colloid and Interface Science, Journal Year: 2024, Volume and Issue: 683, P. 1175 - 1187

Published: Dec. 16, 2024

Language: Английский

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