Boronic acid-modified magnetic materials for antibody purification

Area of Science:

• Biochemistry
• Materials Science
• Biotechnology

Background:

• Aminophenyl boronic acids interact with cis-diols, enabling selective binding of glycoproteins like antibodies.
• Antibodies possess oligosaccharides in their Fv and Fc regions, making them targets for boronic acid-based affinity ligands.

Purpose of the Study:

• To develop and evaluate amino phenyl boronic acid-functionalized magnetic particles (APBA_MP) for efficient antibody molecule separation.
• To assess the binding capacity, selectivity, and purification performance of APBA_MP for human IgG (hIgG).

Main Methods:

• Iron oxide magnetic particles (MPs) were coated with dextran and 3-glycidyloxypropyl trimethoxysilane for APBA functionalization.
• APBA_MP were used to isolate human IgG (hIgG) from pure protein solutions and Chinese hamster ovary (CHO) cell supernatants.
• Binding and elution capacities, affinity constants, and purity of isolated IgG were analyzed.

Main Results:

• APBA_MP demonstrated high binding capacity for hIgG (170 mg g(-1) MP) with excellent elution (160 mg g(-1) MP) and high selectivity over bovine serum albumin (BSA).
• Estimated affinity constant (Ka) was 4.9 × 10(5) M(-1) and theoretical maximum capacity (Qmax) was 492 mg hIgG g(-1) MP, significantly outperforming control particles.
• Direct purification from CHO cell supernatants yielded >98% pure IgG with 95% recovery under mild conditions, binding 98% of loaded IgG.

Conclusions:

• APBA-functionalized magnetic particles are effective for selective and high-capacity antibody purification.
• The developed method offers a promising approach for antibody isolation under mild conditions, suitable for biotechnological applications.
• This technique provides a robust platform for separating and purifying antibody molecules from complex biological mixtures.