Protein A resins are the most frequently used affinity resins in biomanufacturing. Protein A chromatography is a very robust purification procedure and is used as a capture step due to its specificity. Today Protein A chromatography is the standard technique for capturing recombinant monoclonal antibodies. Depending on the intended use for the target molecule (antibodies for diagnostic testing) Protein A capturing might be the only chromatographic step required to achieve adequate product purity.
TOYOPEARL Protein A Resins
Tosoh Bioscience offers two Protein A affinity resins, both based on alkaline stable, recombinant ligands coupled to the proven TOYOPEARL polymethacrylate matrix. Both ligands are recombinant protein A variants expressed in E. coli. They are derived from one of the IgG binding domains of protein A. The ligand of TOYOPEARL AF-rProtein A-650F consists of a tetramer of theses modified protein A C domains. For the ultra-high capacity TOYOPEARL AF-rProtein A HC-650F, this domain was further optimized and expressed as a hexamer in order to further increase IgG binding capacity. Multipoint attachment of the ligands to the TOYOPEARL matrix enhances the chemical and thermal stability of the resins.
Both resins are based on the TOYOPEARL HW-65F base bead with a particle size of 45 μm and exhibit excellent pressure-flow characteristics. The new ultra-high capacity TOYOPEARL AF-rProtein A HC-650M excels all other commercially available protein A media with regard to its IgG binding capacity of >65 g IgG/L resin.