The effect of polyelectrolyte binding affinity on selective coacervation of proteins with the cationic polyelectrolyte, poly(diallyldimethylammonium chloride) (PDADMAC), was investigated for bovine serum albumin/β-lactoglobulin (BSA/BLG) and for the isoforms BLG-A/BLG-B. High-sensitivity turbidimetric titrations were used to define conditions of complex formation and coacervation (pH(c) and pH(...

Polyelectrolyte-colloid coacervation could be viewed as a sub-category of complex coacervation, but is unique in (1) retaining the structure and properties of the colloid, and (2) reducing the heterogeneity and configurational complexity of polyelectrolyte-polyelectrolyte (PE-PE) systems. Interest in protein-polyelectrolyte coacervates arises from preservation of biofunctionality; in addition, ...

We review theories of polyelectrolyte (PE) coacervation, which is the spontaneous association oppositely charged units PEs and phase separation into a polymer-dense in aqueous solution. The simplest can be divided “physics-based” “chemistry-based” approaches. In former, are treated as charged, long-chain, molecules, defined by charge level, chain length, flexibility, but otherwise lacking chemi...

Spindle assembly required during mitosis depends on microtubule polymerization. We demonstrate that the evolutionarily conserved low-complexity protein, BuGZ, undergoes phase transition or coacervation to promote assembly of both spindles and their associated components. BuGZ forms temperature-dependent liquid droplets alone or on microtubules in physiological buffers. Coacervation in vitro or ...

The formation of isodesmosine and desmosine in vitro by the action of lysyl oxidase on tropoelastin was studied. The synthesis of desmosines occurred in the absence of additional substances. The formation of desmosines was not affected by removal of molecular O2 from the reaction medium nor was it affected by the lack of proline hydroxylation in tropoelastin. However, there was virtually no des...

The tropoelastin monomer undergoes stages of association by coacervation, deposition onto microfibrils, and cross-linking to form elastic fibers. Tropoelastin consists of an elastic N-terminal coil region and a cell-interactive C-terminal foot region linked together by a highly exposed bridge region. The bridge region is conveniently positioned to modulate elastic fiber assembly through associa...

Following cellular secretion into the extracellular matrix, tropoelastin is transported, deposited, and cross-linked to make elastin. Assembly by coacervation was examined for an isoform of tropoelastin that lacks the hydrophilic domain encoded by exon 26A. It is equivalent to a naturally secreted form of tropoelastin and shows similar coacervation performance to its partner containing 26A, the...

Coacervation is usually defined as the spontaneous formation of a dense liquid phase from a macromolecular solution of poor solvent affinity. In "coacervation", the loss of solvation arises from the interaction of complementary macromolecular species. The formation of such macromolecule-rich fluids is well-known in mixtures of complementary polyelectrolytes; it can also occur from mixtures of p...

The discovery of membraneless organelles (MLOs) formed by liquid-liquid phase separation raised many questions about the spatial organization biomolecular processes in cells, but also offered a new tool to mimic cellular media. Since disordered and charged protein domains are often necessary for separation, coacervates can be used as models both understand MLO regulation develop dynamic cellula...

Liquid-liquid phase transitions in complex mixtures of proteins and other molecules produce crowded compartments supporting in vitro transcription and translation. We developed a method based on picoliter water-in-oil droplets to induce coacervation in Escherichia coli cell lysate and follow gene expression under crowded and noncrowded conditions. Coacervation creates an artificial cell-like en...