Pilot-scale purification of α-lactalbumin from enriched whey protein concentrate by anion-exchange chromatography and ultrafiltration

Abstract

A method based on anion exchange chromatography (AIEX) in combination with ultrafiltration (UF) was developed to obtain kilogram-scale amounts of bovine α-lactalbumin (α-La) of high purity from α-La-enriched whey protein concentrate (αWPC). Initially, α-La was successfully purified, at laboratory scale, from a 10% solution of αWPC. Removal of casein and denatured whey protein by acid precipitation resulted in a α-La purity of 78%. A further purification by AIEX eluting with sodium acetate (NaAc) buffer led to a final purity and recovery of 100 and 85%, respectively. Based on this, the process was simplified and optimized for pilot-scale purification by selective binding of β-lactoglobulin (β-Lg). Batchwise expanded bed AIEX using a column with 5 L of Q Sepharose matrix was performed. Pure α-La was obtained in the run through buffer. In the end, 1100 g of holo form α-La was obtained with a purity of 97.4% in protein and a recovery of 80%, calculated based on the protein detectable in reversed phase high-performance liquid chromatography (RP-HPLC). Thus, by combining AIEX and UF, heating was avoided allowing production of α-La in kilo-scale with high purity and recovery from αWPC with a minimum volume of buffer solutions.

Production of highly purified fractions of α-lactalbumin and β-lactoglobulin from cheese whey using high hydrostatic pressure

“…With 75% purity and 95% yield of α-LA, this treatment could achieve higher purification and yield than those obtained by chromatography (90.6 and 47.9%, respectively, using affinity) or filtration (80 and 10%, respectively, using ultrafiltration; Gurgel et al, 2000;Holland et al, 2012). Moreover, the approach presented in this study could reach the highest degree of purification and highest yield, similar to those obtained from a combination of affinity chromatography and selective precipitation (90 and 80%, respectively) or of cation exchange chromatography and ultrafiltration (97.4 and 80%, respectively; Blomkalns and Gomez, 1997;Geng et al, 2015). However, comparisons of protein purities and yields should be done carefully because the method of quantification and the degree of denaturation of the initial protein may differ from one work to the other.…”

Variable surface transport modalities on functionalized nylon films revealed with single molecule spectroscopy

“…The effects of surface functionalization on analyte adsorption are of profound interest to the elds of separation and puri-cation sciences and their corresponding multi-billion dollar industries. [1][2][3][4] Functionalization of a membrane or surface changes the interfacial chemical properties and thus can tune the ability of a surface to interact with target molecules [5][6][7][8][9] without changing the other bulk properties of the membrane. 10,11 The performance of a functionalized surface for ltration or separation is difficult to determine a priori because heterogeneous surface dynamics cause deviations from predictive models, [12][13][14] especially when the target molecules are large and complex like proteins.…”

One-step chromatographic method to purify α-lactalbumin from whey for nanotube synthesis purposes

“…However, they did not indicate the protein concentration on that whey, so we cannot compare the yields. Geng et al (2015) described an interesting work where α-LA was purified from α-LA-enriched-WPC treated with different steps of diafiltration and precipitation to obtain a prepurified solution. Then a chromatographic step was applied achieving good results (Table 1).…”

“…In the last chromatographic method, proteins are selectively eluted using a salt gradient (Neyestani et al, 2003) or a pH gradient (Tarhan & Harsa, 2014). Only a few works describing the application of a single chromatographic method are found in the literature (Geng, Tolkach, Otte, & Ipsen, 2015;Liang, Chen, Chen, & Chen, 2006;Mao et al, 2017), whose results (Table 1) we pretend to improve.…”