Engineered-Micelles: Alternative to Protein A Chromatography?

Guy Patchornik , Chemical Sciences, Ariel University , Ariel , Israel (guyp@ariel.ac.il)
Gunasekaran Dhandapni, Chemical Sciences, Ariel University, Ariel, Israel

We introduce a new concept and a potentially general platform for antibody (Ab) purification that does not rely on chromatography nor specific ligands (e.g. Protein A); rather, it makes use of detergent aggregates capable of efficiently capturing Ab's while rejecting hydrophilic impurities. Captured Ab's are then extracted from the aggregates in pure form (>95%) without co-extraction of hydrophobic impurities or aggregate dissolution. The aggregates studied consist of conjugated "Engineered-micelles" built from the nonionic detergent, Tween-20; the hydrophobic metal chelator, bathophenanthroline and Fe²⁺ions. When tested in serum-free media with\without BSA (or HSA) as additives, human or mouse IgG's were recovered at high overall yields (74-80%). Extraction of IgG's with 7 different buffers at pH 3.8 sheds light on possible interactions between captured Ab's and their surrounding detergent matrix. Extracted Ab's preserve their secondary structure, specificity and monomeric character as determined by CD, ELISA and DLS, respectively. Possible integration of the approach within industrial-scale downstream processing of therapeutic grade monoclonal Ab's, will be discussed.