title: Ligand-Induced Cross-Linking of Z-Elastin-like Polypeptide-Functionalized E2 Protein Nanoparticles for Enhanced Affinity Precipitation of Antibodies.
abstract: Affinity precipitation is an ideal alternative to chromatography for antibody purification because it combines the high selectivity of an affinity ligand with the operational benefits of precipitation. However, the widespread use of elastin-like polypeptide (ELP) capture scaffolds for antibody purification has been hindered by the high salt concentrations and temperatures necessary for efficient ELP aggregation. In this paper, we employed a tandem approach to enhance ELP aggregation by enlarging the dimension of the capturing scaffold and by creating IgG-triggered scaffold cross-linking. This was accomplished by covalently conjugating the Z-domain-ELP (Z-ELP) capturing scaffold to a 25 nm diameter E2 protein nanocage using Sortase A ligation. We demonstrated the isothermal recovery of IgG in the virtual absence of salt due to the significantly increased scaffold dimension and cross-linking from multivalent IgG-E2 interactions. Because IgG cross-linking is reversible at low pH, it may be feasible to achieve a high yielding IgG purification by isothermal phase separation using a simple pH trigger.
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of Delaware , Newark, Delaware 19716, United States.
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Swartz
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of Delaware , Newark, Delaware 19716, United States.
authors.forename: Qing
authors.initials: Q
authors.lastname: Sun
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of Delaware , Newark, Delaware 19716, United States.
authors.forename: Wilfred
authors.identifier: http://orcid.org/0000-0002-6386-6958
authors.initials: W
authors.lastname: Chen
mesh_terms: D019881:Aminoacyltransferases / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism; D003432:Cross-Linking Reagents; D003546:Cysteine Endopeptidases / Q000378:metabolism; D004549:Elastin / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007074:Immunoglobulin G / Q000737:chemistry; D047468:Immunoprecipitation / Q000379:methods*; D008024:Ligands; D053758:Nanoparticles / Q000737:chemistry*; D009994:Osmolar Concentration; D010455:Peptides / Q000737:chemistry*; D017510:Protein Folding; D011768:Pyruvate Dehydrogenase Complex / Q000737:chemistry
chemical_list: D001426:Bacterial Proteins; D003432:Cross-Linking Reagents; D007074:Immunoglobulin G; D008024:Ligands; D010455:Peptides; D011768:Pyruvate Dehydrogenase Complex; D004549:Elastin; D019881:Aminoacyltransferases; C120542:sortase A; D003546:Cysteine Endopeptidases