Partitioning of bovine lactoferrin in aqueous two-phase system containing poly(ethylene glycol) and sodium citrate

Abstract

ATPS Molar mass PEG pH Phase diagram Whey protein a b s t r a c tThe partitioning of the whey protein lactoferrin, which is an iron transporter glycoprotein, in an aqueous two-phase system composed of poly(ethylene glycol) (PEG) and sodium citrate was evaluated. Equilibrium data at 25 • C were determined for each system studied using PEG with a molar mass of 1000 and 4000 g mol −1 at pH values of 5.5, 6.5, and 7.5. An increase in the molar mass of the polymer promoted the expansion of the two-phase region and caused the migration of the lactoferrin to the salt-rich bottom phase. An increase in pH also led to the expansion of the biphasic region. However, changing the pH over the tested range slightly affected protein partitioning. Lactoferrin recovery percentages greater than 94% were observed for all of the systems evaluated. The results indicated that lactoferrin can be successfully partitioned in an aqueous two-phase system formed of 14% (w/w) PEG and 10% (w/w) sodium citrate at pH 5.5 and 25 • C. The protein was concentrated 1000-fold in the salt-rich bottom phase in this system. of purity and recovery; and (iii) be efficient, effective, and economical for large-scale processes. Aqueous two-phase systems (ATPS) are an alternative for separating, concentrating, and purifying biologically active molecules such as proteins in complex mixtures. ATPS are formed by mixing either two polymers (such as poly(ethylene glycol)/dextran) or one polymer http://dx.

Extraction of protease from ora‐pro‐nobis ( Pereskia aculeata Miller) and partial purification in polyethylene glycol + sodium phosphate aqueous two‐phase system

“…Although the Kp values indicate a preferential partition of proteins to the lower phase, for all systems studied, it was verified that proteins with proteolytic activity remained in greater concentration in the upper phase ( Ke > 1). Since the lower phase has greater hydrophilicity, it is possible to infer that the proteases from OPN have a hydrophobic character (Costa et al., 2015). The increase in Ke is observed with the increase in TLL since this parameter can favor the interaction between the molecule and the constituents of the system.…”

“…These interactions can be expressed in terms of Gibbs free transfer energy (Δ G ) which is defined as the free energy associated with the transfer of the biomolecule from the saline phase to the polymeric phase. Thermodynamically, Δ G is divided into contributions of an enthalpic and entropic nature (Costa et al., 2015; Johansson et al., 1998; Mageste et al., 2009).…”

Selective extraction of lactoferrin from acidic whey using CTAB/n-heptanol reverse micellar system

“…Ionic liquid based three-phase partitioning (ILTPP) was used by Alvarez-Guerra and Irabien (2014) for LF extraction from bovine whey and 74 to 99% LF recovery has been observed at the interface of the system. Partitioning of commercially available LF was studied in an aqueous two-phase system formed by PEG4000 (10% w/w)-sodium citrate (14% w/w) and a 1000-fold increase of LF concentration in the salt-rich bottom phase was reported (Da Costa et al 2015).…”

Enrichment of Lactoferrin by a Simple Process Based on Solid Phase Extraction

“…Lactoferrin (Lf) is a glycoprotein of transferrins group and is found in mammals' milk in low concentrations (20-200 µg L −1 ) (Wakabayashi et al 2006). It is constituted by 690 amino acid residues, including all essential amino acids, and has a molecular weight of 80 kDa (da Costa et al, 2015). Lf structure (Fig.…”