Two-phase aqueous micellar systems: an alternative method for protein purification

Abstract

-Two-phase aqueous micellar systems can be exploited in separation science for the extraction/purification of desired biomolecules. This article reviews recent experimental and theoretical work by Blankschtein and co-workers on the use of two-phase aqueous micellar systems for the separation of hydrophilic proteins. The experimental partitioning behavior of the enzyme glucose-6-phosphate dehydrogenase (G6PD) in two-phase aqueous micellar systems is also reviewed and new results are presented. Specifically, we discuss very recent work on the purification of G6PD using: i) a two-phase aqueous micellar system composed of the nonionic surfactant n-decyl tetra(ethylene oxide) (C 10 E 4 ), and (ii) a two-phase aqueous mixed micellar system composed of C 10 E 4 and the cationic surfactant decyltrimethylammonium bromide (C 10 TAB). Our results indicate that the two-phase aqueous mixed (C 10 E 4 /C 10 TAB) micellar system can improve significantly the partitioning behavior of G6PD relative to that observed in the two-phase aqueous C 10 E 4 micellar system.

Dextran sulfate/Triton X two-phase micellar systems as an alternative first purification step for clavulanic acid

“…As can be seen, cloud-point values at similar Dx-S concentrations were always lower for TX-114; T CLOUD of TX-100 in the presence only of buffer is approximately 65 C. Taking into consideration that for alkylphenol ethoxylated surfactants the T CLOUD increases with the enhance of polyethylene glycol (PEO) chain and decreases with the hydrophobic tail increase, higher T CLOUD values were expected for TX-100 [25]. It is known that the minimum of the coexistence curve is referred to as the lowest critical point, characterized by a critical temperature (T c ) and a critical surfactant concentration [26]. At any given temperature above T c , a tie line, which is a line in the temperatureconcentration phase diagram along which phase separation proceeds, is obtained by drawing a line parallel to the surfactant concentration axis.…”

Liquid–liquid extraction of biomolecules: an overview and update of the main techniques

“…69,70,75 In addition, a theoretical description was developed to model the partitioning behavior of hydrophilic proteins in two-phase aqueous nonionic micellar systems based on statistical thermodynamics. 70 According to this theory, the partitioning of proteins is governed primarily by repulsive, steric, excluded-volume interactions between the globular hydrophilic proteins and the noncharged cylindrical micelles, which drive the proteins preferentially to the micelle-poor phase.…”

Influence of salts on the coexistence curve and protein partitioning in nonionic aqueous two-phase micellar systems

“…In these systems, an aqueous surfactant solution, under the appropriate solution conditions, spontaneously separates into two predominantly aqueous, yet immiscible, liquid phases, one of which has a greater concentration of micelles than the other (Liu et al, 1998;Rangel-Yagui et al, 2004). The difference between the physicochemical environments in the micelle-rich and in the micelle-poor phases forms the basis for an effective separation and makes ATPMS a convenient and potentially useful method for the separation, purification, and concentration of biomaterials (Liu et al, 1996;Dutra-Molino et al, 2014).…”