title: Hydrophobic interaction chromatography in dual salt system increases protein binding capacity.
abstract: Hydrophobic interaction chromatography (HIC) uses weakly hydrophobic resins and requires a salting-out salt to promote protein-resin interaction. The salting-out effects increase with protein and salt concentration. Dynamic binding capacity (DBC) is dependent on the binding constant, as well as on the flow characteristics during sample loading. DBC increases with the salt concentration but decreases with increasing flow rate. Dynamic and operational binding capacity have a major raw material cost/processing time impact on commercial scale production of monoclonal antibodies. In order to maximize DBC the highest salt concentration without causing precipitation is used. We report here a novel method to maintain protein solubility while increasing the DBC by using a combination of two salting-out salts (referred to as dual salt). In a series of experiments, we explored the dynamic capacity of a HIC resin (TosoBioscience Butyl 650M) with combinations of salts. Using a model antibody, we developed a system allowing us to increase the dynamic capacity up to twofold using the dual salt system over traditional, single salt system. We also investigated the application of this novel approach to several other proteins and salt combinations, and noted a similar protein solubility and DBC increase. The observed increase in DBC in the dual salt system was maintained at different linear flow rates and did not impact selectivity.
authors.affiliation: Purification Process Development, Amgen, Inc., 1201 Amgen Court West, Seattle, Washington 98119, USA. senczuka@amgen.com
authors.forename: Anna M
authors.initials: AM
authors.lastname: Senczuk
authors.forename: Ralph
authors.initials: R
authors.lastname: Klinke
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Arakawa
authors.forename: Ganesh
authors.initials: G
authors.lastname: Vedantham
authors.forename: Yinges
authors.initials: Y
authors.lastname: Yigzaw
mesh_terms: D002845:Chromatography / Q000379:methods*; D057927:Hydrophobic and Hydrophilic Interactions; D011485:Protein Binding; D011506:Proteins / Q000302:isolation & purification* / Q000378:metabolism*; D012492:Salts / Q000378:metabolism*
chemical_list: D011506:Proteins; D012492:Salts