scholarly journals A Tug of War Between Condensate Phases in a Minimal Macromolecular System

2020 ◽  
Author(s):  
Archishman Ghosh ◽  
Xiaojia Zhang ◽  
Huan-Xiang Zhou
Keyword(s):  
Compositional Change ◽  
Binary Forms ◽  
Cationic Protein ◽  
Complex Phase ◽  
Macromolecular System ◽  
Phase Behaviors ◽  
Change Transformation ◽  
Oppositely Charged ◽  
Over Time ◽  
Liquid Liquid Phase Separation

AbstractMembraneless organelles formed via liquid-liquid phase separation (LLPS) contain a multitude of macromolecular species. A few of these species drive LLPS while most serve as regulators. The LLPS of SH35 (S) and PRM5 (P), two oppositely charged protein constructs, was promoted by a polyanion heparin (H) but suppressed by a cationic protein lysozyme (L). Here, using these four components alone, we demonstrate complex phase behaviors associated with membraneless organelles and uncover the underlying physical rules. The S:P, S:L, and P:H binaries form droplets, but the H:L binary forms precipitates, therefore setting off a tug of water between different phases within the S:P:H:L quaternary. We observe dissolution of precipitates upon compositional change, transformation from precipitates to droplet-like condensates over time, and segregation of S:L-rich and P:H-rich foci inside droplet-like condensates. A minimal macromolecular system can thus recapitulate membraneless organelles in essential ways and provide crucial physical understanding.

Mapping the Complex Phase Behaviors of Aqueous Mixtures of κ-Carrageenan and Type B Gelatin

2015 ◽  
Vol 119 (30) ◽  
pp. 9982-9992 ◽  
Author(s):  
Yiping Cao ◽  
Lu Wang ◽  
Ke Zhang ◽  
Yapeng Fang ◽  
Katsuyoshi Nishinari ◽  
...  
Keyword(s):  
Type B ◽  
Aqueous Mixtures ◽  
Complex Phase ◽  
Phase Behaviors

A light scattering study of interactions of oppositely charged proteins in solution

2007 ◽  
Vol 1061 ◽  
Author(s):  
Perumal Radha Ramasamy ◽  
Raafat Elmaghrabi ◽  
Gary Halada ◽  
Miriam Rafailovich
Keyword(s):  
Light Scattering ◽  
Zeta Potential ◽  
Fluorescent Dyes ◽  
Cationic Protein ◽  
Cationic Proteins ◽  
Low Concentrations ◽  
Scattering Study ◽  
Fluorescent Tags ◽  
Oppositely Charged ◽  
Electrophoresis Of Proteins

ABSTRACTIn experiments involving electrophoresis of proteins in gels, it was observed that the mobility of FITC tagged albumin (FITC albumin) was greater than that of TRITC tagged albumin (TRITC albumin). To further understand the effects of tagging proteins with fluorescent dyes, interactions of anionic proteins FITC albumin and untagged bovine serum albumin (BSA), with cationic protein ploy-L-lysine was studied using dynamical light scattering. It was found that aggregates formed by the interaction of FITC albumin with poly-L-lysine were larger than those formed by the interaction between poly-L-lysine and BSA. Using zeta potential measurements it was observed that irrespective of the fluorescent tags attached to them, the zeta potential values of cationic proteins changed from negative to positive with increasing amounts of poly-L-lysine. It was also observed that addition of small amounts of poly-L-lysine to solutions containing FITC albumin decreased the zeta potential drastically. To explain this data, we are proposing a model that suggests that low concentrations of poly-L-lysine serve as scaffold - like structures on which several FITC albumin molecules anchor. We conclude that FITC appears to change the surface charge of albumin significantly and thereby influencing its behavior in solution and its interaction with cationic poly-L-lysine.

scholarly journals Binary Solutions of Hyaluronan and Lactose-Modified Chitosan: The Influence of Experimental Variables in Assembling Complex Coacervates

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 897
Author(s):  
Federica Vecchies ◽  
Pasquale Sacco ◽  
Eleonora Marsich ◽  
Giuseppe Cinelli ◽  
Francesco Lopez ◽  
...  
Keyword(s):  
Hyaluronic Acid ◽  
Electrostatic Interactions ◽  
Weight Ratio ◽  
Mutual Solubility ◽  
Molecular Weights ◽  
Modified Chitosan ◽  
Ph Values ◽  
Oppositely Charged ◽  
Liquid Liquid Phase Separation

A miscibility study between oppositely charged polyelectrolytes, namely hyaluronic acid and a lactose-modified chitosan, is here reported. Experimental variables such as polymers’ weight ratios, pH values, ionic strengths and hyaluronic acid molecular weights were considered. Transmittance analyses demonstrated the mutual solubility of the two biopolymers at a neutral pH. The onset of the liquid-liquid phase separation due to electrostatic interactions between the two polymers was detected at pH 4.5, and it was found to be affected by the overall ionic strength, the modality of mixing and the polymers’ weight ratio. Thorough Dynamic Light Scattering (DLS) measurements were performed to check the quality of the formed coacervates by investigating their dimensions, homogeneity and surface charge. The whole DLS results highlighted the influence of the hyaluronic acid molecular weight in affecting coacervates’ dispersity and size.

scholarly journals Non-associative phase separation in an evaporating droplet as a model for prebiotic compartmentalization

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Wei Guo ◽  
Andrew B. Kinghorn ◽  
Yage Zhang ◽  
Qingchuan Li ◽  
Aditi Dey Poonam ◽  
...  
Keyword(s):  
Phase Separation ◽  
Liquid Phase ◽  
Building Blocks ◽  
In Vitro Transcription ◽  
Liquid Phase Separation ◽  
Sessile Droplet ◽  
And Storage ◽  
Oppositely Charged ◽  
Liquid Liquid Phase Separation

AbstractThe synthetic pathways of life’s building blocks are envisaged to be through a series of complex prebiotic reactions and processes. However, the strategy to compartmentalize and concentrate biopolymers under prebiotic conditions remains elusive. Liquid-liquid phase separation is a mechanism by which membraneless organelles form inside cells, and has been hypothesized as a potential mechanism for prebiotic compartmentalization. Associative phase separation of oppositely charged species has been shown to partition RNA, but the strongly negative charge exhibited by RNA suggests that RNA-polycation interactions could inhibit RNA folding and its functioning inside the coacervates. Here, we present a prebiotically plausible pathway for non-associative phase separation within an evaporating all-aqueous sessile droplet. We quantitatively investigate the kinetic pathway of phase separation triggered by the non-uniform evaporation rate, together with the Marangoni flow-driven hydrodynamics inside the sessile droplet. With the ability to undergo liquid-liquid phase separation, the drying droplets provide a robust mechanism for formation of prebiotic membraneless compartments, as demonstrated by localization and storage of nucleic acids, in vitro transcription, as well as a three-fold enhancement of ribozyme activity. The compartmentalization mechanism illustrated in this model system is feasible on wet organophilic silica-rich surfaces during early molecular evolution.

scholarly journals KIRSAL ALAN YEREL KİMLİKLERİNİN OLUŞUM VE GELİŞİMİNE İÇ VE DIŞ DİNAMİKLERİN ETKİSİ: BABAYAKUP KÖYÜ ÖRNEĞİ

2020 ◽  
Vol 15 (4) ◽  
pp. 113-128
Author(s):  
Begüm Demiroğlu ◽  
Bahtiyar Eroğlu ◽  
Fatih Semerci
Keyword(s):  
Aerial Photographs ◽  
Specific Time ◽  
Chronological Order ◽  
Time Intervals ◽  
Literature Reviews ◽  
The Matrix ◽  
Change Transformation ◽  
External Behavior ◽  
External Interventions ◽  
Over Time

As the science of settlement morphology is done intensively, it can be done at any time that settlements have similar setups but built on it. The aim of the study is to reveal the dynamics used in the analysis of settlement morphology and the changes/transformations in a specific time place, to define internal and external interventions, to enter and fulfill the existing field, and to reveal the change/transformation and transformation predictions in the invention from the first installation to the present. This study was chosen as a sample area for the study because of the readability of the changes in immigration and internal/external behavior over time in Babayakup village, one of the villages (neighborhood) of Polatlı district, Polatlı district in Ankara province. In the research; Aerial photographs, parts, examinations, oral interviews, literature reviews, computer programs to be studied were arranged. The entire realization was achieved by placing it in the matrix in chronological order, followed by comparative analysis. While reading the changes/transformations in the time intervals encountered during the study period, the predictions will come for the coming years, by looking at the duration of differentiation.

Coacervation-driven instant paintable underwater adhesives with tunable optical and electrochromic properties

2021 ◽  
Author(s):  
Qiongyao Peng ◽  
Jingsi Chen ◽  
Tao Wang ◽  
Lu Gong ◽  
Xuwen Peng ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Phase Separation ◽  
Liquid Phase ◽  
Liquid Phase Separation ◽  
Solution Phase ◽  
Dilute Solution ◽  
Electrochromic Properties ◽  
Oppositely Charged ◽  
Liquid Liquid Phase Separation ◽  
Coacervate Phase

Coacervation generally refers to liquid-liquid phase separation when mixing oppositely charged polyelectrolytes in an aqueous solution, which produces a polyelectrolyte‐dense coacervate phase in a dilute solution phase. Coacervation plays a...

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