Nonionic detergent micelle aggregates: an economical alternative to
Protein A chromatography
Abstract
We have recently described a non-chromatographic, ligand-free approach
for antibody (Ab) purification based on specially designed:
[Tween-20:bathophenanthroline:Fe2+] aggregates. To assess the
potential generality of this approach, a variety of detergents belonging
to four nonionic detergent families (Tween, Brij, Triton and Pluronic)
have now been studied. All surfactant aggregates lead to high purity of
the recovered Abs (>95%, by gel densitometry). Good
overall Ab recovery yields were observed with: Tween-20 (80-83%),
Brij-O20 (85-87%) and Triton X-100 (87-90%), while Pluronic F-127 was
less efficient (42-53%). Of additional importance is the finding that
the process can depend on filtration (rather than centrifugation),
thereby allowing a continuous purification mode that leads to the
recovery of monomeric IgG’s (by DLS) and preservation of Ab specificity
(by ELISA). The amphiphilic chelator, bathophenanthroline (batho) is
recycled almost quantitatively (95%) by crystallization. Good IgG
recovery yields (~80%) are also observed when Ab
concentrations are increased from 1 mg/ml to 3-5 mg/mL. Potential
advantages of the purification platform for industrial downstream
processing of therapeutic monoclonal antibodies (mAbs), are discussed.