A New Mixed-Mode Resin for Large Scale Biomolecule Purification

Chromatographic resins with high capacities and selectivities differing from those seen with traditional hydrophobic interaction and ion exchange media are now in demand. Mixed-mode chromatography media is an alternative. Some mixed-mode resins combine both traditional hydrophobic interaction and ion exchange media. This poster introduces TOYOPEARL® MX-Trp-650M, a high-capacity weak cation mixed-mode resin for the purification of biomolecules.

The polymethacrylic base bead was chemically modified with the amino acid tryptophan which combines a weak cationic group with a hydrophobic functional group. The resulting resin exhibited high dynamic binding capacities (approximately 90 mg/mL for IgG). Separation of proteins from crude feedstocks with measured conductivities of 12 mS/cm was routinely possible. Increasing the salt concentration up to 200 mmol/L NaCl at pH values as low as 4.0 also had capacities usable in large scale biomolecule purifications.

Experiments were performed to compare TOYOPEARL MX-Trp-650M selectivity with two commercially available cation exchange resins and a commercially available mixed-mode resin. The selectivity was demonstrated by the elution of three common proteins at different pH values. Overall, TOYOPEARL MX-Trp-650M selectivity was different from the cation exchange media as well as the other commercially available mixed-mode resin.