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The plant plasma membrane (PM) is the outermost membrane of the cell and constitutes the cell border across which nutrients are imported and metabolic products exported. It is also the site for receptors recording the environment and the interphase between the cell wall and the cytoskeleton. ...

Plasma membranes from various sources, e.g., higher plants (1), green algae (2), cyanobacteria (3), and yeast (4,5) have, during the last two decades, been isolated in pure state by the two-phase partitioning method. The aqueous two-phase method is, in addition to being mild, rapid, and reproducible, ...

Cyanobacteria, as gram-negative bacteria, are surrounded by a cell envelope consisting of the outer membrane and the plasma membrane with a peptidoglycan layer in between. However, cyanobacteria, is a unique prokaryote, because in addition to the cell envelope, there is an inner cytoplas ...

This chapter describes the purification of rat liver plasma membranes by affinity partitioning in an aqueous polymer two-phase system using the lectin wheat germ agglutinin (WGA) as affinity ligand. Affinity partitioning is advantageous for conventional membrane fractionat ...

In addition to its application as a separation process, aqueous two-phase partitioning often yields information on important physical properties of proteins, replacing other more cumbersome analytical techniques. For example, aqueous two-phase partitioning can be used to mea ...

Partitioning in aqueous two-phase systems (ATPS) is mainly a process where the exposed groups of molecules come into contact with the phase components, and is therefore surface-dependent (1). Among the main protein properties, hydrophobicity and charge appear to be the most important pa ...

All biological life is dependent on interactions. On the molecular level, interactions between proteins, nucleic acids, and lipids are required for formation of the organelles, as well as other cellular structures such as cytoskeletons, ribosomes, and multienzyme complexes. In addi ...

Aqueous two-phase systems, based on two polymers, usually freeze at temperatures below -1�C. The freezing point can be considerably lowered by exchanging part of the water for a water miscible organic solvent such as ethylene glycol or glycerol (1). Partitioning of proteins and particles has ...

Solvent extraction is a proven technology for the recovery of metal ions from aqueous solution (1,2). Through the application of different diluents, extractants, and aqueous phase conditions, the technique may be adapted to handle a wide variety of solutes. Extraction kinetics are often r ...

The extraction of proteins in aqueous phase systems is one of the most rapid purification methods available, and very useful for separation of cell debris.

Partition behavior of amino acids and peptides in the aqueous two-phase (ATP) systems is of academic and practical importance for the following reasons.

An important use for aqueous two-phase systems is in protein purification processes for the removal of cell disintegrate and nucleic acids in combination with partial protein purification. When a phase system is to be applied in the primary purification of an intracellular protein, the op ...

The expression of eukaryotic proteins in a foreign host is frequently accompanied by the formation of aggregates or inclusion bodies of inactive proteins that accumulate within the cell (1),(2). Although inclusion bodies have been found mainly in Escherichia coli, they have also been found ...

This chapter covers the use of aqueous two-phase systems for extracting and purifying enzymes and other proteins of interest from animal tissue. This area was the subject of a general review by the author in 1990 (1).

Extraction systems based on nonionic surfactants have been described as an alternative to the standard polymer/polymer or polymer/salt systems. Phaseforming surfactants are, for example, the nonionic polyoxyethylene-type detergents. This kind of aqueous two-phase system ( ...

Ethylene oxide (EO)-propylene oxide (PO) random copolymers are watersoluble and separate into two phases above a lower critical solution temperature (LCST), i.e., the cloud point, a polymer-rich phase, and a water phase depleted of polymer. Traditionally, the removal of polymer from prot ...

The partitioning of biopolymers and bioparticles between the two phases of polymer-polymer aqueous two-phase systems depends on the kind of electrolytes present in the system. This is a consequence of the ionic charge of the partitioned material and the difference in affinity of cation and ...

Many biological processes, such as regulation, catalysis, and complex formation, depend on the capacity of biopolymers to interact with apolar groups, i.e., their surface or “effective” hydrophobicity (1). The determination of surface hydrophobicity is therefore important for un ...

Two-phase extraction of protein mixtures leads to one or several protein fractions, which also contain mainly one of the phase-forming polymers. To separate proteins from the phase polymer, a number of methods can be used (1). If proteins and polymer differ strongly in their respective molecu ...

The partitioning in aqueous two-phase systems (ATPS) has become an established and well-known method for the separation and purification of biological materials (1–1). In order to increase the selectivity and effectiveness of the separation, a ligand that partitions favorably into o ...