Phosphatide auto-complex coacervates as ionic systems and their relation to the protoplasmic membrane

Biomolecular condensation of the microtubule-associated protein tau

“…LLPS is a phenomenon inherent to the thermodynamics of liquids [7,36,37]. Complex fluids gain unique thermodynamic, rheological, and other physical properties through liquid-liquid demixing: the two states -homogeneous and phase-separated state -have different free energies depending on temperature and pressure [38].…”

“…Coacervation (Table 1) of oppositely charged molecules (e.g. protein and RNA, or protein and polyelectrolyte) promotes LLPS [37,48], highlighting the importance of electrostatic interactions for biomolecular LLPS [18,47,49]. In addition, hydrophobic interactions can influence protein LLPS (please see 2.1.…”

Small Amphiphile‐Based Coacervation

“…Additionally, intracellular LLPS of RNA‐binding proteins, such as hnRNPA1, [10,11] TDP‐43 [10] and FUS, [12,13] are found to be closely related to neurodegenerative diseases (e. g., amyotrophic lateral sclerosis, ALS) [14,15] . On the other hand, Oparin proposed the concept of coacervation underlying the origin of life in the 1930s, following the research of LLPS in gum Arabic and gelatin system by Bungenberg de Jong and Kruyth [16,17] . Recently, coacervate droplets are generally regarded as attractive candidates of protocell models since they can be formed by simple prebiotically relevant molecules, offering a compartmentalized entity isolated from the surroundings, selectively accumulating biochemical molecules and acting as a hub of chemical reactions [18,19] .…”

“…[14,15] On the other hand, Oparin proposed the concept of coacervation underlying the origin of life in the 1930s, following the research of LLPS in gum Arabic and gelatin system by Bungenberg de Jong and Kruyth. [16,17] Recently, coacervate droplets are generally regarded as attractive candidates of protocell models since they can be formed by simple prebiotically relevant molecules, offering a compartmentalized entity isolated from the surroundings, selectively accumulating biochemical molecules and acting as a hub of chemical reactions. [18,19] These membraneless droplets are also capable of generating a chemical gradient by concentrating target molecules and maintaining dynamic exchange with the environment.…”

Stabilizing Coacervate by Microfluidic Engulfment Induced by Controlled Interfacial Energy

“…Complex coacervation, a fluid–fluid separation phenomenon, occurs when two oppositely charged polyelectrolytes are mixed in an aqueous solution at optimal ranges of concentrations, pH, and ionic strength. − When the oppositely charged polycations and polyanions are mixed in an aqueous solution (Figure A-i), they form dense coacervate droplets to neutralize their charges during the complex coacervation (Figure A-ii), and eventually the coacervate droplets coalesce with each other and separate into a dense coacervate phase (Figure A-iii). The coacervate is a highly dense liquid phase with up to ∼2000 mg/mL of complexed polyelectrolytes, and it can hold the desired cargo substances. − In addition, it possesses an extremely low interfacial energy (generally lower than 2 mN/m) in aqueous solutions, making it possible to encapsulate most substances in aqueous solutions. ,− These two key properties make the coacervate a good asset in encapsulation technology for various applications such as drugs carrier, nanoparticles, flavor additives, adhesive, fragrances, explosives, and cells. − ,− Notably, these two properties have been used to postulate the biological significance of the coacervate: the origin of life, the carrier across the biological membrane and membrane-less organelles. − …”