Demonstration of a Strategy for Product Purification by High-Gradient Magnetic Fishing: Recovery of Superoxide Dismutase from Unconditioned Whey

Abstract

A systematic approach for the design of a bioproduct recovery process employing magnetic supports and the technique of high-gradient magnetic fishing (HGMF) is described. The approach is illustrated for the separation of superoxide dismutase (SOD), an antioxidant protein present in low concentrations (ca. 0.15-0.6 mg L(-1)) in whey. The first part of the process design consisted of ligand screening in which metal chelate supports charged with copper(II) ions were found to be the most suitable. The second stage involved systematic and sequential optimization of conditions for the following steps: product adsorption, support washing, and product elution. Next, the capacity of a novel high-gradient magnetic separator (designed for biotechnological applications) for trapping and holding magnetic supports was determined. Finally, all of the above elements were assembled to deliver a HGMF process for the isolation of SOD from crude sweet whey, which consisted of (i) binding SOD using Cu2+ -charged magnetic metal chelator particles in a batch reactor with whey; (ii) recovery of the "SOD-loaded" supports by high-gradient magnetic separation (HGMS); (iii) washing out loosely bound and entrained proteins and solids; (iv) elution of the target protein; and (v) recovery of the eluted supports from the HGMF rig. Efficient recovery of SOD was demonstrated at approximately 50-fold increased scale (cf magnetic rack studies) in three separate HGMF experiments, and in the best of these (run 3) an SOD yield of >85% and purification factor of approximately 21 were obtained.

Mechanism of Free Radical Scavenging and Role of Phytohormones in Plants Under Abiotic Stresses

“…SOD regulates the concentration of superoxide anionic radical, and it has received great attention because of its protective effect against oxygen toxicity (Nordberg and Arner 2001). Hence, SOD has gained considerable interest in the pharmaceutical and food industries (Meyer et al 2005). The over-expression of SODs combats the negative effects of oxidative stress and has a significant role in tolerance and survival of plants.…”

Controlled heteroaggregation of two types of nanoparticles in an aqueous suspension

“…Such magnetic nanoparticles have attracted a lot of attention in biomedicine, for example, in drug delivery or in the detection and targeting of specific (bio)molecules or cells [1][2][3][4][5]. They can also be used in technologies related to magnetic separation, particularly in environmental engineering [6,7], in chemical engineering [8,9], or in bioseparation processes [10][11][12]. Magnetic separation is a technique where magnetic carriers, i.e., small particles of a magnetic material, are dispersed into a liquid mixture containing specific targets, e.g., ions, such as toxic heavy metals, biomolecules, including proteins and enzymes, or cells and microorganisms [13,14].…”

Future of antibody purification

“…This has been adapted from chemical and mineral processing industries for protein separations [128][129][130]. Small (sub-micron) superparamagnetic particles are formed from magnetite crystals and are coated with polyglutarldehyde, which can then be derivatized to provide different selectivities.…”